Valve Junior Full Stack

[rocknroller]

Hi,

 

I'm basically clueless when it comes to electronics and wiring and don't have a soldering iron so I apologize if this has been covered before (is it just me or is the search function useless. It seems no matter how direct I try to make the keywordd I get pages of unrelated posts to my topic. Anyway, I have 2 EVJ extension cabs that I want to hook up to my EVJ head without having to do any wiring or adding output jacks to the speaker cabs. Can I just use this 1/4" mono Y-adapter from Radio shack and plug a cable from each cab into it, and then plug the adapter into the 8-ohm input on the head? http://www.radioshack.com/product/index.jsp?productId=2103712#

 

I also thought I read somewhere where you can just plug one cab into the 16ohm input on the head and the other into the 8ohm. Would either of these "simple" solutions work for a simpleton like me?

 

Thanks in advance,

Fred

[Jan Vigne]

Hi,

 

I'm basically clueless when it comes to electronics and wiring and don't have a soldering iron so I apologize if this has been covered before (is it just me or is the search function useless. It seems no matter how direct I try to make the keywordd I get pages of unrelated posts to my topic. Anyway, I have 2 EVJ extension cabs that I want to hook up to my EVJ head without having to do any wiring or adding output jacks to the speaker cabs. Can I just use this 1/4" mono Y-adapter from Radio shack and plug a cable from each cab into it, and then plug the adapter into the 8-ohm input on the head? http://www.radioshack.com/product/index.jsp?productId=2103712#

 

I also thought I read somewhere where you can just plug one cab into the 16ohm input on the head and the other into the 8ohm. Would either of these "simple" solutions work for a simpleton like me?

 

Thanks in advance,

Fred

 

 

First, check this thread; http://forum.gibson.com/index.php?/topic/56882-impedance-matching/

 

You can use a "Y" splitter to split an output but not that one. You'll need a 1/4" phone lug (male) split to two 1/4" female jacks. Don't use a "Y" connector to combine two inputs to a pre amp, amp or source. The "Y" will place both cabinets in parallel which will result in approximately half the lowest impedance point of either cabinet. Two 8 Ohm nominal cabinets in parallel would result in a load best suited to the 4 Ohm tap. Lower impedance loads place more stress on the amplifier. If your intent is to overdrive the amp, this might be problematic. It would be much better IMO to run the two cabinets in series which will raise the nominal impedance to 2X the lowest impedance point. As a general rule, tubes output more voltage than current, which makes them more suited to higher impedance loads of 8-16 Ohms. Solid state amps are optimized for full power output at 8 Ohms but can typically get by with a solid 4 Ohm load without much trouble. A solid state amp will often increase its total available wattage into a lower impedance load while a transformer coupled amp (tubes) will output roughly the same wattage from each output transformer tap. In the case of the Valve jr, that's five watts into 16, 8 or 4 Ohms. This doubling of power sounds great but doesn't amount to much in reality. Doubling the amp's wattage will only porvide about 3dB of additional headroom. That's hardly noticeable on peaks and not at all at lesser volumes. You need to go 10 times the wattage to actually have the peaks reach twice the volume level. It's easier to find a more electrically sensitive speaker than it is to buy lots-o-watts. There will probably be slightly less overall volume with a series rather than a parallel connection but it's a more stable load which will allow the amp to IMO sound better.

 

http://search.yahoo.com/search?ei=utf-8&fr=slv8-hptb5&p=parallel%2fseries%20speaker%20connection&type=

 

When making a daisy chained parallel or series connection the first speaker from the amp will receiver the lion's share of the amp's "power" which will mean the two cabinets might not play at equal sound pressure levels (SPL's; http://www.goodsearch.com/search.aspx?source=goodshopbar&keywords=sound+pressure+level) Also, make note that in a series connection, should one speaker system stop working, the other speaker will also stop working. If this should happen, you should check both speakers individually for proper operation and you'll possibly still have a cabinet to use.

[mtheory]

He's got two 16 ohm cabinets, so it wouldn't be advisable to run them in series. The best way to run them both from a single head would be to add a parallel-wired, second jack to one of the cabinets, plug the second cabinet into that additinoal jack, and plug into the 8 ohm tap on the amp. I have a strong dislike for mickey mouse solutions, and those flimsy little Y-cables are 100% mickey mouse. It takes so very little effort to do this the right way, that I just can't see advising anything less. Don't cheap out on the jack, either, and while you're installing a new SWITCHCRAFT for that additional jack, buy an extra 3, so you can add a second jack to the other cabinet and replace the crappy, plastic junk jacks that came in the cabinets. Do it right the first time, and you won't have to revisit it in the future. Mickey mouse it, and you'll almost certainly be redoing it later on.

[mtheory]

Also, make note that in a series connection, should one speaker system stop working, the other speaker will also stop working. If this should happen, you should check both speakers individually for proper operation and you'll possibly still have a cabinet to use.

 

But, not likely an amp. It takes a mere instant to fry an output transformer, when a tube amp is pushed and into no load.

[Jan Vigne]

But, not likely an amp. It takes a mere instant to fry an output transformer, when a tube amp is pushed and into no load.

 

 

I guess to begin with you shouldn't be "pushing" the amp if you are troubleshooting. IMO the simplest way to test a speaker for basic function is with a small battery. I don't know if most guitarists keep any spare cabling around for such things but you would need to either access the terminals of the driver (speaker) or have a dummy cable with the appropriate plug on one end and bare wires on the other. With the leads connected to the "+" and "-" terminals of the driver (or the dummy cable inserted into the input of the cabinet) hold one bare wire conductor leg on the "-" terminal of the battery and flick the other bare conductor end across the "+" terminal. If the speaker is at all operational, the diaphragm should move (forward and backward) when the battery is applied and removed from across its terminals. If the diaphragm is frozen, the driver is dead. If it first moves backward and then forward, reverse the polarity of the wires on the battery.

 

With two 16 Ohm cabinets a series connection isn't the best choice, no, though the amp should survive the load. The grafted on jack is the best way but now we're dealing with someone who doesn't claim much electrical knowledge to do such things. Experience is something you can gain from doing a simple modification like this. If you're at all nervous about drilling into the cabinet to install the jack and make the connections, then it would be best to spend the money to allow a technician to do the work.

[mtheory]

I guess to begin with you shouldn't be "pushing" the amp if you are troubleshooting

This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on. And, since a series speaker connection will take both speakers down if one goes down, there's a strong possibility of frying the output transformer, if that should happen. It only takes a very brief moment of running the amp with no load, to smoke that iron.

 

I personally wouldn't run a 32 ohm load with this amp, or any other amp that didn't have a 32 ohm tap, for that matter...at least not without first putting it on a scope to see how angry the amp gets under that mismatch. The stock iron in this thing isn't terribly robust. It MIGHT survive, but I sure wouldn't put money on it.

 

I realize that Fred doesn't have much experience in soldering, but adding a jack is a very simple, rather painless way for him to gain some of that experience. Yes, a tech would certainly do this, for a nominal fee of minimum bench labor (generally $50-$60) and the cost of the jacks, but it's really something that anybody with a pair of hands, at least one good eye, and at least a minimal amount of common sense and rudimentary knowledge, even if only gathered from the web, could tackle successfully. I'd certainly be willing to guide him along, as I'm sure several others around here would. This is one of those very basic skills that every guitarist should put into his arsenal, if for no other reason than to fix a broken cable now and then. It's a skill that, once gathered and brought into use, will stay with him and be useful to him for the rest of his life. "teach a man to fish..." ;-)

[Jan Vigne]

This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on. And, since a series speaker connection will take both speakers down if one goes down, there's a strong possibility of frying the output transformer, if that should happen. It only takes a very brief moment of running the amp with no load, to smoke that iron.

 

I personally wouldn't run a 32 ohm load with this amp, or any other amp that didn't have a 32 ohm tap, for that matter...at least not without first putting it on a scope to see how angry the amp gets under that mismatch. The stock iron in this thing isn't terribly robust. It MIGHT survive, but I sure wouldn't put money on it.

 

I realize that Fred doesn't have much experience in soldering, but adding a jack is a very simple, rather painless way for him to gain some of that experience. Yes, a tech would certainly do this, for a nominal fee of minimum bench labor (generally $50-$60) and the cost of the jacks, but it's really something that anybody with a pair of hands, at least one good eye, and at least a minimal amount of common sense and rudimentary knowledge, even if only gathered from the web, could tackle successfully. I'd certainly be willing to guide him along, as I'm sure several others around here would. This is one of those very basic skills that every guitarist should put into his arsenal, if for no other reason than to fix a broken cable now and then. It's a skill that, once gathered and brought into use, will stay with him and be useful to him for the rest of his life. "teach a man to fish..." ;-)

 

 

 

 

At the risk if antagonizing someone when we've both just started to post on this forum ...

 

"This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on.

 

I'm not seeing a logical cause and effect in your claims. Class A operation means nothing more than the amplifier is not being run in class AB, C, D, or so on. In other words, class A operation implies only that the circuit lacks a phase splitter which would divide the top and bottom half of each waveform between two discrete output devices. In a class A amplifier there is no division of its duty cycle between two different/discrete output devices as in the other modes of operation. In class A one device (or muliptle devices in parallel), say, one tube or one transistor, is never cycled "off" and therefore handles the entire 180 degrees of both the "+" and "-" waveforms. For the most part, that's really all "class A" implies.* Along with that comes greater inefficiencies (due to the constant duty cycle) which are expressed in (typically) lower power output and higher heat dissipation but those are relative values. (If your amplifier has a "Pentode/Triode" switch, flipping from pentode to triode will also mean lower power output. There are numerous considerations when it comes to efficiencies in an circuit.) A "potentially" 25 watt amplifier running in class A will not produce "higher heat dissipation" or, IMO, be "stressed" when run at 1 watt. So running the amp at 7 O'Clock on the volume control will be far less stressful than running the amp at 5 O'Clock. This is a function of the amount of voltage and current passing through the amplifier and the resultant heat (which is the loss associated with any amplifier's gain stages) and not strictly its class of operation. Push any amplifier operating in any duty cycle or "class" and it's going to get hotter and be more stressed. We're hoping for common sense on the part of the user here.

 

There's a lot of confusion about the "class" of operation and what it exactly means to the amplifier. I se comments like this, "Class A amps with two (or 4) output tubes are also push/pull circuits." No, the amp could simply have paralleled outputs to increase total wattage. Claiming "Class A" automatically states the amplifier cannot be a push/pull design. I don't doubt you can find some very bizarre claims for what class A and AB "do". Here's my evidence for my claims;

 

 

 

In a Class A circuit, a positive voltage is applied to the Grid, which controls the flow of electrons. In this circuit design current is flowing at all times through the tube. In a Class "AB" design a negative "bias" voltage is applied to the grid, which will cause the tube to "shut off" when the audio waveform is below a certain point. Meanwhile there is another tube and associated circuit that is turning on before the first one turns off and is reproducing the rest of the waveform. In short these two tubes share the job of reproducing the full audio waveform.

http://www.sweetwater.com/expert-center/techtips/d--01/12/2005

 

 

Classes of biasing of an amplifier. Biasing refers to a constant power being consumed by an amplifier or its output stage.

 

The term class A refers to biasing of the output stage (in a transistor power amp). Bias is an engineering term that actually means what it implies (i.e. Leaning in one direction). By that, we refer to the amount of current flowing through the output stage.

 

Class A is when both devices conduct at all times while Class B is when only one device is on at any instant. These are both limiting cases and there is thus a setting between these two limits where, for small signal levels, both devices conduct but for larger levels, only one conducts. This is termed Class AB.

 

Class AB is not a true class, but is a very common term applied to the biasing levels used in most audio amplifiers. The output stage is biased to carry a quiescent current significantly less than half the maximum output current, (as needed for full Class A) but sufficient to keep both devices running in Class A for small output signals. However as the output signal increases, the amplifier becomes Class B with one device cutting off on each half cycle. This biasing scheme effectively moves the linearity curves toward one another resulting in a transfer curve that is more linear as it passes through the origin. This scheme approaches the efficiency of class B yet offers class A distortion levels (nearly) especially for small output levels where class B suffers most.

http://www.psaudio.com/ps/knowledge/what-is-the-difference-between-class-a-and-class-ab

 

 

D. What is Class A, B, AB, ultralinear, etc?

 

1. Class A means that the power tube conducts the same amount of current all the time, whether idling or producing full power. Class A is very inefficient with electricity but usually gives very low distortion.

 

There are single-ended class-A, or SE, amplifiers. They use one or more tubes in parallel, which are all in phase with each other. This is commonly used in smaller guitar amps and in exotic high-end amplifiers. Many audiophiles prefer the SE amplifier, even though it has relatively high levels of even-order distortion. Most 300B high-end amplifiers are SE. Negative feedback, which can be used to decrease the distortion of an amplifier, is felt by some people to sound inferior. Most SE amps have no feedback.

Push-pull class-A amplifiers also exist--they use two, four or more tubes (always in pairs) which are driven in opposite phase to each other. This cancels out the even-order distortion and gives very clean sound. An example of a class-A push-pull amplifier is the Vox AC-30 guitar amp. Push-pull Class A operation usually involves low plate voltages and high plate currents, compared to Class AB operation below. The high currents might tend to wear out the tube cathodes faster than in an AB amplifier.

There are two kinds of class-A operation, which can apply to single-ended or push-pull.

--Class A1 means that the grid voltage is always more negative than the cathode voltage. This gives the greatest possible linearity and is used with triodes such as the SV300B, and with audio beam tetrodes and pentodes.

--Class A2 means that the grid is driven MORE POSITIVE than the cathode for part or all of the waveform. This means the grid will draw current from the cathode and heat up. A2 is not often used with beam tetrodes, pentodes or triodes like the SV300B, especially in audio. Usually a class-A2 amplifier will use tubes with special rugged grids, such as the SV811 and SV572 series of triodes.

Class A2 also requires a special driver circuit, that can supply power to the grid.

 

2. Class AB applies only to push-pull amplifiers. It means that when one tube's grid is driven until its plate current cuts off (stops) completely, the other tube takes over and handles the power output. This gives greater efficiency than Class A. It also results in increased distortion, unless the amplifier is carefully designed and uses some negative feedback. There are class-AB1 and class-AB2 amplifiers; the differences are the same as were explained above--the tube's grids are not (AB1) or are (AB2) driven positive.

http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm

 

 

 

*Class A operation will always be single ended. With only one output device carrying the full duty cycle it can be nothing else and therefore cannot be p/p just as p/p is not se and therefore cannot be class A. Circular logic is sometimes a wonderful thing. Most pre amps operate in class A for higher linearity and lower distortion (there is a lack of "crossover" or "notch" distortion [http://www.aikenamps.com/CrossoverNotchBiasing.html] inherent in class A) since there is insufficient voltage and current to stress the circuits. I wouldn't say the pre amp section of a class AB "amplifier" is necessarily "being pushed if it's on". If the circuit is operating in any other class than class A, the circuit will be a push/pull design and will require two output devices minimum - one for each half of the waveform. More than that would be a paralleled output in a push/pull circuit. http://www.aikenamps.com/CrossoverDistortion.htm

 

 

 

"I personally wouldn't run a 32 ohm load with this amp, or any other amp that didn't have a 32 ohm tap, for that matter...at least not without first putting it on a scope to see how angry the amp gets under that mismatch.

 

 

Tubed power amplifiers generally prefer high impedance loading to low impedance loading which demands more current be delivered through the outputs. Current is not so much what tubed power amplifiers do well. They prefer high impedance loads which exist on voltage feed, that is as long as the total load remains fairly stable - not much of a problem for guitar speakers without crossovers. But, we agree, the VJ will potentially suffer some loss of power with the higher load - that's Ohm's Law. Using two 16 Ohm speaker systems in series probably isn't the best approach here. I hadn't realized the cabinets were each 16 Ohm. My advice would still stand should the cabinets be of a lower impedance.

 

 

 

"It only takes a very brief moment of running the amp with no load, to smoke that iron.

 

 

IMO that depends on the amp and the abuse it has been taking. It is the self induced oscillation from the "open" negative feedback loop which is the most common cause for "unloaded" transformer failure. In most amps that will take awhile to do serious damage. If you stand there for a few minutes and wonder why the sound stopped, you risk failure. If you immediately shut the amplifier down, then you're chances of still having a workable amp increase expotentially. Once again, common sense is all we expect. A more well designed and executed and more therefore more stable amp can probably run for an hour or more without a load - not that I'm suggesting anyone try this for verification. The stock VJ is a budget amplifier. Budget amplifiers tend to live closer to the edge than the boutique and high dollar stuff. The user should - we would hope, common sense and all being the key - have an actual idea of what they have and that it is not a 100 watt Marshall head or a 300 watt McIntosh amplifier. If you want volume, buy a speaker system with a higher electrical sensitivity spec. A five watt amplifier playing into a 94dB speaker will sound more like a 15 watt amplifier when it works into a 100dB speaker - and it will have to work less hard to do so.

 

 

 

I would guess if the op had someone to provide minimal assistance with the addition of the jacks, he should be able to accomplish this. On the other hand, good solder joints do take time and practice to accomplish and a crappy solder joint is, IMO, far more frustrating than a cheap "Y" splitter you can throw away and replace. The op needs to decide which is the better option with the permanent fix being highly suggested but with cautions.

[Jan Vigne]

 

"mtheory" isn't a "noob" here

 

:o :)

 

He sure knows what he speaks about....IMO

 

 

"I don't have any reason to lie to you - I just do it for fun"

 

 

 

Awwww, now how do I know you're telling the truth?

 

 

 

 

Sorry, I'm going by the word "Newbie" on his post and that of the op, and his post number looks like a new member's. I stand corrected. He sounds like he has a fair amount of experience and information to share. I just disagree with his concept of class A operation and the value of soldering jacks for a real admitted noobie. Civil disagreement is not a bad thing, is it? I've provided some proof of what I say for others to judge and he can do the same. Don't forget, we actually agree on several things.

[mtheory]

Jan, I think you're confused about what the members of this forum are. You seem to think that we're all either EEs or budding EEs, or at the very least, that we're all interested in reading EE literature. It appears that you, for one, have some interest in becoming one, and I applaud that, but I don't think it's all that useful to others around here to C&P this type of literature. We tend to speak in English as much as possible around here.

 

Beyond that, I personally have spent a great deal of time over the past 10 years with a friend who happens to have spent a good portion of the past 40 years sniffing solder over countless tube guitar amps. The man is, in short, an "amp whisperer." I cannot even count how many times he's scolded me for bringing EE literature "absolutes" to him.

 

He's seen it all, and I can assure you, the information that you're finding and posting is NOT absolute, in guitar amp world. There are a WHOLE lot of things that happen inside a tube guitar amp, especially when things start to distort. Why do you think nobody has been able to create a solid state version of a tube amp that convinces anyone? If it were as simple as the math involved, don't you think we'd have no use for tubes at this point?

 

Some of us tinker here more than others, and, by extension, happen to have some real world experience beyond others, and are willing to share it. This forum has been a rather low-key, humble, friendly, non-intimidating place for average folks to gather and share information, in a manner that makes it useful for other forumites. In all due respect, Jan, you're coming off as pretentious and snobbish, and not at all helpful. You're muddying the water, to say the least. Try to think of whom you're addressing around here. You're not teaching an EE class at MIT.

 

I stand by what I've said previously, and I'll further add that it really doesn't matter whether a tube amp is class A or B, or if it's pushed or not, if there's no load connected. It WILL FRY THE OUTPUT. Tube amps do NOT like not having a speaker load. Period. You are welcome to argue that until you turn blue in the face, but it will not change the facts, I assure you. If you still cannot believe it, try it out for yourself, and see how it works for you. Better yet, go visit an actual tube amp tech and try to convince him that you know more about his work than he does.

 

As for teaching a man to fish, by encouraging him to solder in his own jack, I stand by that as well. Far more can be accomplished by reaching out to help someone with something that you're capable of helping him with, than by intimidating him through a flood of documentation that makes absolutely no sense whatsoever to him.

[mtheory]

Oh, and yes, I've been lurking and posting around here for probably 5 years or so. When the brilliant masterminds at Gibson decided to overtake the forum and host it through their server, they magically made it impossible for me to post with my other moniker, m-theory. I contacted them more than once to alert them to the issue and request resolution, but my requests were ignored, so I finally just created a new name and carried on.

[Jan Vigne]

Jan, I think you're confused about what the members of this forum are. You seem to think that we're all either EEs or budding EEs, or at the very least, that we're all interested in reading EE literature. It appears that you, for one, have some interest in becoming one, and I applaud that, but I don't think it's all that useful to others around here to C&P this type of literature. We tend to speak in English as much as possible around here.

 

Beyond that, I personally have spent a great deal of time over the past 10 years with a friend who happens to have spent a good portion of the past 40 years sniffing solder over countless tube guitar amps. The man is, in short, an "amp whisperer." I cannot even count how many times he's scolded me for bringing EE literature "absolutes" to him.

 

He's seen it all, and I can assure you, the information that you're finding and posting is NOT absolute, in guitar amp world. There are a WHOLE lot of things that happen inside a tube guitar amp, especially when things start to distort. Why do you think nobody has been able to create a solid state version of a tube amp that convinces anyone? If it were as simple as the math involved, don't you think we'd have no use for tubes at this point?

 

Some of us tinker here more than others, and, by extension, happen to have some real world experience beyond others, and are willing to share it. This forum has been a rather low-key, humble, friendly, non-intimidating place for average folks to gather and share information, in a manner that makes it useful for other forumites. In all due respect, Jan, you're coming off as pretentious and snobbish, and not at all helpful. You're muddying the water, to say the least. Try to think of whom you're addressing around here. You're not teaching an EE class at MIT.

 

I stand by what I've said previously, and I'll further add that it really doesn't matter whether a tube amp is class A or B, or if it's pushed or not, if there's no load connected. It WILL FRY THE OUTPUT. Tube amps do NOT like not having a speaker load. Period. You are welcome to argue that until you turn blue in the face, but it will not change the facts, I assure you. If you still cannot believe it, try it out for yourself, and see how it works for you. Better yet, go visit an actual tube amp tech and try to convince him that you know more about his work than he does.

 

As for teaching a man to fish, by encouraging him to solder in his own jack, I stand by that as well. Far more can be accomplished by reaching out to help someone with something that you're capable of helping him with, than by intimidating him through a flood of documentation that makes absolutely no sense whatsoever to him.

 

 

 

 

 

Hmmmmm ...

 

At the risk of antagonizing anyone at all ...

 

You put me in the rather awkward position of defending not my knowledge but myself personally. More over you've confused me. You promote "teaching a man to fish" yet, if I make an attempt at providing that man some real knowledge of fishing, it is seen as "pretentious and snobbish". This forum, as you describe it, "has been a rather low-key, humble, friendly, non-intimidating place for average folks to gather and share information, in a manner that makes it useful for other forumites." Yet any facts I present are seen not as "information" but as "muddying the water ... You're not teaching an EE class at MIT." Just for the record, I don't claim to be an engineer, a designer nor a real technician. But "electronics" has been my hobby and my career for decades. I try to know what I'm talking about before I say anything and I've found it useful not even to attempt knowing everything but to know how to find what is required. It is the paradox of knowing enough that you realize how much there is still to learn.

 

"I don't think it's all that useful to others around here to C&P this type of literature" implies I'm posting pornography or something far worse - a challenge to learn. I have to say, mtheory, I find that rather insulting and closeminded.

 

Before you find yourself insulted, I did not come to this forum to make enemies - or friends for that matter. I consider forums to be places where discussion takes place and an honest and civil exchange of ideas might occur without food fights. I see I've rocked the boat and that bothers me. Therefore, as briefly as I can state them, here are the "principles" of how I - a newbie to this forum - go about all this. I say what I feel I can prove when proof is needed and do not state what I know I cannot prove. I do have many strong opinions but they are my own and they are seldom expressed. I encourage subjective opinions based upon knowledge and to the extent they become "priorities" which inform your decisions. Buying blindly is a terrible waste of money and time practiced by far too many. I will find proofs when called upon to do so and I hope others will do the same. I encourage a discussion of ideas but not of "take it or leave it" opinions. I would like to hear what others have to say and I would hope they respect my input as much as they intend for me to respect their's. And, no matter the outcome of a discussion, I don't hold grudges or carry one thread over to the next until someone has proven to me I should. I'm not expecting it to come to that on a low key forum. That said, I do approach things logically just as I was taught to do by a certain nun who insisted there were no shortcuts to logic or proof. And from that stand point, mtheory, your "I personally have spent a great deal of time over the past 10 years with ... an "amp whisperer" is, in terms of logic, what is known as an "argument from authority", a "strawman" and a "red herring". (Excuse the link here but I feel it might do some good to once again teach a man to fish; http://www.logicalfallacies.info/) That you know someone talented is no guarantee of you knowing ampifiers. That your "expert" rejected absolutes does not mean there are no absolutes. And, I have to add, since you played that card, I too have my own list of "authorities" with whom I've sniffed some solder and singed some fingers. However, I think we've all played the game of passing a sentence from one person to the next and having the final turn be outrageously not like the original. My one opinion I will state is, technically, I feel I know enough to know when to get my hands out of a piece of equipment. To me that's important while to others it's dive in and see your if heart doesn't stop. I don't claim to always be right but I realize we all can hold incorrect opinions, None of that changes the facts of how class A operates. Your "pretentious and snobbish" etc. are low key ad hominems which are meant to say I don't know anything because I present facts rather than your opinions. "Pretentious" of me to point that out, I suppose, but a fact none the less.

 

 

"He's seen it all, and I can assure you, the information that you're finding and posting is NOT absolute."

 

I have to disagree once more and say, yes, how class A operates is an absolute, your "assurances" to the contrary not withstanding. Whether this amp/guitar/beer is better than that amp/guitar/beer has no aboslute, how class A operates does. The reason I can say that is I inserted the proofs for what I claimed. You, mtheory, have done nothing more (beyond castigating me) than say you are right because you say you are right. That too is a logical fallacy. "Far more can be accomplished by reaching out to help someone with something that you're capable of helping him with, than by intimidating him through a flood of documentation that makes absolutely no sense whatsoever to him." But you don't see the presentation of available facts as "something that you're capable of helping him with"? If someone feels "intimidated" by the links I provide, they are under no obligation to read them. We all learn as we prefer to learn and at the pace we can tolerate. They are there for the sake of those who prefer to know things rather than run on blind faith and marketing slogans. Others can move on as they wish. No one needs to fear factual information and I fail to see how your argument against me personally makes my argument of the operation of class A circuits any the less factual. Neither are they intended to "attack" you or your opinion, merely to defend my own.

 

 

Before this becomes too longwinded and complaints are lodged against how many words I post I will stop here and ask you, metheory, not to argue against me personally but rather to defend your concept of class A, "This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on." This, "There are a WHOLE lot of things that happen inside a tube guitar amp, especially when things start to distort. Why do you think nobody has been able to create a solid state version of a tube amp that convinces anyone? If it were as simple as the math involved, don't you think we'd have no use for tubes at this point?", is another logical fallacy and does not even make sense. This argues, first, we do not know tubes therefore we cannot know class A operation - which is false. Solid state has nothing to do with this, class A is essentially the same in tubes or transistors. And, secondly, you argue that we do not understand tube amps and, therefore, we shouldn't try to understand tube amps. Well, maybe we could learn about tubes amps and how they operate anyway, eh? Wouldn't that be the better idea? Do you not learn the major scales just because you don't understand them? Is it to your advantage to go ahead and learn more scales? Even if we never understand everything there is to know about tube amps or scales and many of the opinions about which is "better" remain subjective, wouldn't it be to our advantage to know more today than we did last week? That any individual here might not personally be fully versed in tube amps actually has nothing to do with how class A amps operate. Others do know and they have established those absolutes of "math" (scary word inserted for effect?) which assist others in also understanding. That's a fact.

 

Now, if this goes as most forums go, you're pretty well convinced I've attacked you. That was not my intent. I came to this forum for a civil discussion of information an on ocassion a few opinions. Should we disagree, I feel you are welcome to your own opinions but you are not welcome to your own facts and no red herrings are allowed in - they stink. This need not turn contentious. Simply debate your facts and I'll stand behind mine. After that, everyone gets to form their own opinions. My intent is to inform not to intimidate.

 

 

Finally, "Tube amps do NOT like not having a speaker load. Period. You are welcome to argue that until you turn blue in the face, but it will not change the facts, I assure you. If you still cannot believe it, try it out for yourself, and see how it works for you. Better yet, go visit an actual tube amp tech and try to convince him that you know more about his work than he does." was unnecessary. Read what I've actually posted about this and don't go to the srawman or the attack red herring of falsely claiming I said what you believe you read. We agreee on several things but not as you prefer to see them. I would hope we can work with those things we actually agree on and discuss with civility and respect those things we do not.

 

:D

[mtheory]

Jan, you've made several comments in this thread that either aren't meaningful to the discussion in any way, could be detrimental to the amp in question (32 ohm load? Really? When did you verify that on a scope? You're making a blanket assumption that could very well be harmful to the output section of this amp, regardless of what you may have read somewhere), or were based on nothing but false implication and conjecture on your part (For instance, not ONCE have I stated that we should never attempt to duplicate tube amps with transistors, yet you devoted an entire paragraph to pointing out how "wrong and stupid" I was for saying it. I also NEVER stated that there were NEVER any absolutes, as you've stated I have).

 

I would suggest you learn to be more careful in reading and comprehending what you read, before posting a response. You seem to be rather defensive, and frankly, your positions haven't always been entirely defensible in all cases.

 

Meanwhile, I will continue to stand by everything I've said, because I've seen it all with my own two lying eyes and heard it with my own two lying ears. As for "debating the facts," as I've stated already, there are simply times in tube amp world in which so-called "facts" really aren't entirely relevant. There are general guidelines to follow, such as avoiding applying more B+ voltage to a given tube than the spec sheet says that the tube can handle. But, just because you may have read somewhere that tube amps ALWAYS perform better with higher than recommended speaker loads simply does NOT necessarily make it so. I'm sorry. If you don't wish to believe that, so be it, but I'm telling you that I've seen for myself, the PROOF that this is simply not the case. You've read differently in some book. Big deal. The real world doesn't always follow strict, immoveable, rigid rules. This is especially so in the case of an overdriven tube amp, because when the amp starts to distort, it's beyond the realm of what your books were written to describe.

 

I frankly don't have a clue what your big issue is regarding Class A. In terms of a tube amp not being real happy with no speaker load, it doesn't matter WHAT class it is. ANY tube amp that's run without a speaker load will suffer a toasted output transformer, in VERY short order. I have a friend who fried the OT in a 1974 circuit amp, simply by turning it on and hitting a chord at low volume, with no load. He instantly turned the amp off, but in that short amount of time, he fried his OT. His amp was Class AB, he wasn't pushing it, and he didn't expose it for more time than it took to reach down and turn it off.

 

Yet, YOUR initial comment regarding this VERY REAL threat of a dead OT, was that "you shouldn't be pushing it when performing diagnostics," as if this had ANYTHING to do with what I'd said, or if it had ANY BASIS in fact, which it does NOT. You IMPLIED that one of a pair of series-wired speakers would NEVER fail under load. I reject that notion wholeheartedly. And, I also reject the notion that running a tube amp w/o a speaker load, even for diagnostic purposes, is a good idea or is in some way acceptable practice.

 

Look at what you're defending here, in order to claim some sort of bizarre "victory."

 

1. You feel that series wiring two 16 ohm cabinets in order to show an amp with no higher than a 16 ohm tap, and an output transformer that's inescapably flimsey to begin with, a wicked mismatch of 32 ohms, is a good idea.

 

2. You feel that it's a bad idea for anyone short of a technician to wire up a second jack.

 

3. You feel that tube amps will be fine run without a load, as long as it's done for "diagnostic purposes,"

 

4. You feel that class A amps don't run 100%, all the time.

 

 

I won't even discuss these with you any further, because it's gone on long enough. I promise you, you won't convince me that your opinions on these points are worthy of my adopting them for myself, and it's clear that I won't convince you otherwise, either. We're going to have to simply agree to disagree.

 

However, as to the point of what constitutes the definition of a Class A amp, here's a little C&P to clarify for you:

 

Class A

The amplifier conducts current throughout the entire cycle (360º). The Class A design is the most inefficient and is used in low-power applications as well as in very high-end stereo. Such devices may be as little as 15% efficient, with 85% of the energy wasted as heat.

 

"The amplifier conducts current throughout the entire cycle." In other words, the amp is full on, all the time, just as I'd previously stated. I hope that clears up the confusion. What it means, in REAL world terms, is that, when you turn the amp on, it's running at the output as if the volume was at "10," whether it's at "10" or "1." It doesn't matter to the output section in a class A amp, because that output is running full on, all the time.

[Jan Vigne]

Jan, you've made several comments in this thread that either aren't meaningful to the discussion in any way, could be detrimental to the amp in question (32 ohm load? Really? When did you verify that on a scope? You're making a blanket assumption that could very well be harmful to the output section of this amp, regardless of what you may have read somewhere), or were based on nothing but false implication and conjecture on your part (For instance, not ONCE have I stated that we should never attempt to duplicate tube amps with transistors, yet you devoted an entire paragraph to pointing out how "wrong and stupid" I was for saying it. I also NEVER stated that there were NEVER any absolutes, as you've stated I have).

 

I would suggest you learn to be more careful in reading and comprehending what you read, before posting a response. You seem to be rather defensive, and frankly, your positions haven't always been entirely defensible in all cases.

 

Meanwhile, I will continue to stand by everything I've said, because I've seen it all with my own two lying eyes and heard it with my own two lying ears. As for "debating the facts," as I've stated already, there are simply times in tube amp world in which so-called "facts" really aren't entirely relevant. There are general guidelines to follow, such as avoiding applying more B+ voltage to a given tube than the spec sheet says that the tube can handle. But, just because you may have read somewhere that tube amps ALWAYS perform better with higher than recommended speaker loads simply does NOT necessarily make it so. I'm sorry. If you don't wish to believe that, so be it, but I'm telling you that I've seen for myself, the PROOF that this is simply not the case. You've read differently in some book. Big deal. The real world doesn't always follow strict, immoveable, rigid rules. This is especially so in the case of an overdriven tube amp, because when the amp starts to distort, it's beyond the realm of what your books were written to describe.

 

I frankly don't have a clue what your big issue is regarding Class A. In terms of a tube amp not being real happy with no speaker load, it doesn't matter WHAT class it is. ANY tube amp that's run without a speaker load will suffer a toasted output transformer, in VERY short order. I have a friend who fried the OT in a 1974 circuit amp, simply by turning it on and hitting a chord at low volume, with no load. He instantly turned the amp off, but in that short amount of time, he fried his OT. His amp was Class AB, he wasn't pushing it, and he didn't expose it for more time than it took to reach down and turn it off.

 

Yet, YOUR initial comment regarding this VERY REAL threat of a dead OT, was that "you shouldn't be pushing it when performing diagnostics," as if this had ANYTHING to do with what I'd said, or if it had ANY BASIS in fact, which it does NOT. You IMPLIED that one of a pair of series-wired speakers would NEVER fail under load. I reject that notion wholeheartedly. And, I also reject the notion that running a tube amp w/o a speaker load, even for diagnostic purposes, is a good idea or is in some way acceptable practice.

 

Look at what you're defending here, in order to claim some sort of bizarre "victory."

 

1. You feel that series wiring two 16 ohm cabinets in order to show an amp with no higher than a 16 ohm tap, and an output transformer that's inescapably flimsey to begin with, a wicked mismatch of 32 ohms, is a good idea.

 

2. You feel that it's a bad idea for anyone short of a technician to wire up a second jack.

 

3. You feel that tube amps will be fine run without a load, as long as it's done for "diagnostic purposes,"

 

4. You feel that class A amps don't run 100%, all the time.

 

 

I won't even discuss these with you any further, because it's gone on long enough. I promise you, you won't convince me that your opinions on these points are worthy of my adopting them for myself, and it's clear that I won't convince you otherwise, either. We're going to have to simply agree to disagree.

 

However, as to the point of what constitutes the definition of a Class A amp, here's a little C&P to clarify for you:

 

 

"The amplifier conducts current throughout the entire cycle." In other words, the amp is full on, all the time, just as I'd previously stated. I hope that clears up the confusion. What it means, in REAL world terms, is that, when you turn the amp on, it's running at the output as if the volume was at "10," whether it's at "10" or "1." It doesn't matter to the output section in a class A amp, because that output is running full on, all the time.

 

 

 

"Now, if this goes as most forums go, you're pretty well convinced I've attacked you. That was not my intent."

 

 

Jan, you've made several comments in this thread that either aren't meaningful to the discussion in any way, could be detrimental to the amp in question (32 ohm load? Really?"

 

No, I didn't initially realize the cabinets were 16 Ohm @. "Tubed power amplifiers generally prefer high impedance loading to low impedance loading which demands more current be delivered through the outputs. Current is not so much what tubed power amplifiers do well. They prefer high impedance loads which exist on voltage feed, that is as long as the total load remains fairly stable - not much of a problem for guitar speakers without crossovers. But, we agree, the VJ will potentially suffer some loss of power with the higher load - that's Ohm's Law. Using two 16 Ohm speaker systems in series probably isn't the best approach here. I hadn't realized the cabinets were each 16 Ohm. My advice would still stand should the cabinets be of a lower impedance."

 

"You're making a blanket assumption that could very well be harmful to the output section of this amp, regardless of what you may have read somewhere), or were based on nothing but false implication and conjecture on your part ... "

 

There's no "false implication" (whatever that is supposed to mean) on my part. Read the above. The output section of the VJ amp isn't going to be "harmed" even on a budget amp by working into a higher impedance load. The output transformer's transfer function will be mismatched and a loss of power will result. Sound quality (into a single or multiple common driver) is unlikely to change other than THD will decrease slightly. I've never even considered how high the load impedance would need to be to cause amplifier failure, I suspect several times several that 32 Ohm figure when fed from the 16 Ohm tap and that due finally to the amp simply not producing sufficient voltage into the load - it will eventually sound like crap long before it blows up.

 

 

"(For instance, not ONCE have I stated that we should never attempt to duplicate tube amps with transistors, yet you devoted an entire paragraph to pointing out how "wrong and stupid" I was for saying it."

 

I don't believe I did what you claim. I certainly never used the word "stupid" no matter how you've interpreted my post.

 

" I also NEVER stated that there were NEVER any absolutes, as you've stated I have).

 

Once again, no, I did not. "That you know someone talented is no guarantee of you knowing ampifiers. That your "expert" rejected absolutes does not mean there are no absolutes."

 

"I would suggest you learn to be more careful in reading and comprehending what you read, before posting a response. You seem to be rather defensive, and frankly, your positions haven't always been entirely defensible in all cases"

 

 

"Meanwhile, I will continue to stand by everything I've said, because I've seen it all with my own two lying eyes and heard it with my own two lying ears. As for "debating the facts," as I've stated already, there are simply times in tube amp world in which so-called "facts" really aren't entirely relevant."

 

"Should we disagree, I feel you are welcome to your own opinions but you are not welcome to your own facts and no red herrings are allowed in - they stink. This need not turn contentious. Simply debate your facts and I'll stand behind mine. After that, everyone gets to form their own opinions. My intent is to inform not to intimidate."

 

"There are general guidelines to follow, such as avoiding applying more B+ voltage to a given tube than the spec sheet says that the tube can handle."

 

Well, here I say you could try. You'll be buying tubes constantly and endangering those around you, but, hey! that's life, right? :lol:

 

"But, just because you may have read somewhere that tube amps ALWAYS perform better with higher than recommended speaker loads simply does NOT necessarily make it so. I'm sorry. If you don't wish to believe that, so be it, but I'm telling you that I've seen for myself, the PROOF that this is simply not the case."

 

Can you provide proof I said tube amps will ever - let alone "ALWAYS" - perform better with a higher than "recommended" speaker load? Please refer back to my initial paragraph in this post when doing so.

 

"You've read differently in some book. Big deal."

 

I'm coming to the conclusion books and reading are not your favorite things.

 

"The real world doesn't always follow strict, immoveable, rigid rules."

 

I'm also coming to the conclusion when you are challenged in anyway you resort to personal attacks first and ignoring what was said second. You must get taken to a lot of bars.

 

"This is especially so in the case of an overdriven tube amp, because when the amp starts to distort, it's beyond the realm of what your books were written to describe.

 

Well, no, it's all rather predictable with a bit of tube theory. "X" tube can dissipate "Y" watts and after that the same thing will occur in every tube and every tube circuit. If this were not the case, how would a designer go about building an amp at all? I'm not arguing against the "art" of amplifier design, I highly respect those who can eek out wonderful music from a handful of parts. But amplifiers are not designed in a vacuum (no pun intended), that infamous "math" gets involved and "if A then B" starts working and you can't just grab a bunch of parts and think you can build an amplifier because you once knew an "expert". Things happen much as they are predicted to happen, by the book, and as they have happened for the last 100+ years and it's the highly artful designer who can see where to go from where they are. I'm leaning more and more to the idea you just don't like books or facts. Too much memorization.

 

"I frankly don't have a clue what your big issue is regarding Class A."

 

Really?! I thought I had made it quite obvious. Oh, well, here it is in a nutshell; you posted, ""This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on." I disagree with that statement. After I did so, this turned ugly.

 

"In terms of a tube amp not being real happy with no speaker load, it doesn't matter WHAT class it is."

 

It doesn't, but then I never said it did. I think you might have though.

 

"ANY tube amp that's run without a speaker load will suffer a toasted output transformer, in VERY short order."

 

"IMO that depends on the amp and the abuse it has been taking. It is the self induced oscillation from the "open" negative feedback loop which is the most common cause for "unloaded" transformer failure. In most amps that will take awhile to do serious damage. If you stand there for a few minutes and wonder why the sound stopped, you risk failure. If you immediately shut the amplifier down, then you're chances of still having a workable amp increase expotentially. Once again, common sense is all we expect. A more well designed and executed and more therefore more stable amp can probably run for an hour or more without a load - not that I'm suggesting anyone try this for verification. The stock VJ is a budget amplifier. Budget amplifiers tend to live closer to the edge than the boutique and high dollar stuff. The user should - we would hope, common sense and all being the key - have an actual idea of what they have and that it is not a 100 watt Marshall head or a 300 watt McIntosh amplifier. If you want volume, buy a speaker system with a higher electrical sensitivity spec. A five watt amplifier playing into a 94dB speaker will sound more like a 15 watt amplifier when it works into a 100dB speaker - and it will have to work less hard to do so."

 

"I have a friend who fried the OT in a 1974 circuit amp, simply by turning it on and hitting a chord at low volume, with no load. He instantly turned the amp off, but in that short amount of time, he fried his OT. His amp was Class AB, he wasn't pushing it, and he didn't expose it for more time than it took to reach down and turn it off."

 

Wow! a guitar player blew up his amp. I'm shocked, simply shocked! His amp was AB operation. What's that got to do with the discussion - with any discussion - of class A operation? **** happens, mtheory. Have you ever considered your friend might not be telling the entire truth? Like maybe he'd been pounding it out for weeks and the amp wasn't all that happy with him? Maybe he had that "fuzz/overdrive/crunch" pedal to the max even if the amp wasn't. This is what's called a "strawman". "This" occurred and therefore "this" will always occur. I'm not calling you a liar or even saying you have the points down wrong. But "this" happening doesn't mean "that" always happens. You shouldn't run tube powered amps without speakers. I thought we both had agreed on that?

 

"Yet, YOUR initial comment regarding this VERY REAL threat of a dead OT, was that "you shouldn't be pushing it when performing diagnostics," as if this had ANYTHING to do with what I'd said, or if it had ANY BASIS in fact, which it does NOT."

 

Well, yeah, it kind of does have something to do with the facts. " ... the user should - we would hope, common sense and all being the key - have an actual idea of what they have ... " I suggested testing the cabinets in that one might still be operational. I also provided instructions for checking the speaker without connecting it to the amp. What are you getting so pissed off about? Stop shouting at me!

 

"You IMPLIED that one of a pair of series-wired speakers would NEVER fail under load."

 

You can be tiresome. "Also, make note that in a series connection, should one speaker system stop working, the other speaker will also stop working. If this should happen, you should check both speakers individually for proper operation and you'll possibly still have a cabinet to use." Both drivers will stop due to the series connection. That only one failed is a distinct possibility just as the old series connected Xmas tree lights used to all go out when only one bulb failed. If I completely shut down one volume control on my Sheraton, both pickups stop because they're wired in series.

 

No one ever said or "IMPLIED" "one of a pair of series-wired speakers would NEVER fail under load". You're getting yourself so worked up over this that you aren't even close to reality.

 

"I reject that notion wholeheartedly."

 

What "notion" is that? One of the dozens you've made up about what I posted?

 

"And, I also reject the notion that running a tube amp w/o a speaker load, even for diagnostic purposes, is a good idea or is in some way acceptable practice.

 

One more time, point me to where I said it was.

 

"Look at what you're defending here, in order to claim some sort of bizarre "victory."

 

It's clear there is no "winning" against you, mtheory.

 

"1. You feel that series wiring two 16 ohm cabinets in order to show an amp with no higher than a 16 ohm tap, and an output transformer that's inescapably flimsey to begin with, a wicked mismatch of 32 ohms, is a good idea"

 

Not true. I am at a loss for where you've come up with this BS.

 

"2. You feel that it's a bad idea for anyone short of a technician to wire up a second"

 

"If you're at all nervous about drilling into the cabinet to install the jack and make the connections, then it would be best to spend the money to allow a technician to do the work."

"I would guess if the op had someone to provide minimal assistance with the addition of the jacks, he should be able to accomplish this. On the other hand, good solder joints do take time and practice to accomplish and a crappy solder joint is, IMO, far more frustrating than a cheap "Y" splitter you can throw away and replace. The op needs to decide which is the better option with the permanent fix being highly suggested but with cautions."

 

"3. You feel that tube amps will be fine run without a load, as long as it's done for "diagnostic purposes,"

 

You're not only repeating yourself, now you're drooling on yourself. We've addressed this lie elsewhere in this post.

 

"4. You feel that class A amps don't run 100%, all the time

 

Let's see, amplifiers run 100%, all the time (duh!) when they are powered up. They cease running "all the time" when they are powered down. This has nothing to do with class A operation nor does it suggest the amp is "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on.

 

Any questions out there about this?

 

"I won't even discuss these with you any further, because it's gone on long enough. I promise you, you won't convince me that your opinions on these points are worthy of my adopting them for myself, and it's clear that I won't convince you otherwise, either. We're going to have to simply agree to disagree.

 

No, we're going to have to agree these claims you've made without checking the facts are the rantings of a man who just can't get things straight.

 

""The amplifier conducts current throughout the entire cycle." In other words, the amp is full on, all the time, just as I'd previously stated."

 

 

Here's what you "previously stated" and what I disagreed with, ""This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on. Other than that, you've tried to use my very proof for how class A operates in an attempt to say I am not getting the facts straight. Coming from you at the end of your last post, mtheory, the suggestion you have the facts straight is ... well ... "amusing". Please, go back up and check the information I provided regarding class A operation, it's too long to repeat here. My disagreement is not in how class A amplifiers operate when it comes to duty cycle, I've explained that clearly in my previous post. The point to be made is a 360 degree duty cycle is not considered by anyone to be "pushing the amp" just because it's "on". Class A was for decades the only architecture of an amplifier available until Williamson and his push/pull circuits came along in the late 1940's. Thousands upon thousands of class A amplifiers were sold and used including those in the two Wars. Are you really trying to tell me you believe all of those amplifiers were "pushed every second" they were powered up? Is that really what you mean to say?

 

" I hope that clears up the confusion. What it means, in REAL world terms, is that, when you turn the amp on, it's running at the output as if the volume was at "10," whether it's at "10" or "1." It doesn't matter to the output section in a class A amp, because that output is running full on, all the time."

 

The amplifier has quiescent voltages and current which maintain its operation with or without a signal. For example, the bias current never changes, just the signal level voltage/current through the tube and the circuits. However, it is the signal through the amplifier circuits - which is adjusted in level at the input of the pre amp - which determines how much the amplifier is being "pushed". You can run an amplifier at 0.10 watts all day and it will not be pushed. On the otherhand, you can run a class A, AB, C, etc. amp at full tilt boogie for a few minutes and most amps will respond by generating excessive heat and distortion. This is not exclusive to class A amplifiers.

 

The point all of this has been spun from is that I disagree with, ""This is Class A, so it's "pushed" every second that it's on. It doesn't matter if the volume is at "zero" or at "10," the amp is "being pushed" if it's on." An amplifier of any topology can exist without being "pushed", it does not follow that class A operation in and of itself "pushes" the amplifier "if it's on".

 

 

You've got yourself so worked up over things that do not exist and disagreements which did not occur that you can't even get a single fact straight at this point. It's unfortunate this post needed to be so long, I know this is inconsequential to most. But I have a real problem with anyone who just makes up this sort of BS - most especially when they falsely try to pin the BS to my words. And every line of your last post was BS, mtheory.

 

Whether I sought to antagonize you or whether I did not, I get the feeling you and I are not likely to become "forum buddies", mtheory. That's too bad.

[brianh]

...I have 2 EVJ extension cabs that I want to hook up to my EVJ head without having to do any wiring or adding output jacks to the speaker cabs. Can I just use this 1/4" mono Y-adapter from Radio shack and plug a cable from each cab into it, and then plug the adapter into the 8-ohm input on the head? http://www.radioshac...ductId=2103712#

No, bad idea.

 

I also thought I read somewhere where you can just plug one cab into the 16ohm input on the head and the other into the 8ohm. Would either of these "simple" solutions work for a simpleton like me?

No, bad idea - see m-theory (or mtheory) post #3 above. That's the correct solution.

 

PS: Don't hold the quantity of my posts here against me.

 

PPS: Welcome to the forum Fred!

[mtheory]

I'm all done playing the little word games, Jan. You're welcome to pat yourself on the back and claim "victory," because I've had enough absurdity and excess verbiage over utter nonsense. I'm not even going to bother reading your latest vastly overly-worded monologue, because I've made my points and I proudly and unwaveringly stand by them. If you wish to deny reality, in order to claim your little "victory," so be it. I have either personally witnessed, or have been second hand to a personal witnessing of everything I've said, and that's why I stand by my words. You apparently cannot claim the same, or else you wouldn't have bothered arguing against reason and logic here. Carry on.

[1984 Guy]

Hey Fred, lookie here at this thread. http://forum.gibson.com/index.php?/topic/50763-valve-juniorsenior-1x12-cabinet-parallel-jack/page__p__686101__fromsearch__1#entry686101

 

Its so easy a chimp can do it.

[Jan Vigne]

I'm all done playing the little word games, Jan. You're welcome to pat yourself on the back and claim "victory," because I've had enough absurdity and excess verbiage over utter nonsense. I'm not even going to bother reading your latest vastly overly-worded monologue, because I've made my points and I proudly and unwaveringly stand by them. If you wish to deny reality, in order to claim your little "victory," so be it. I have either personally witnessed, or have been second hand to a personal witnessing of everything I've said, and that's why I stand by my words. You apparently cannot claim the same, or else you wouldn't have bothered arguing against reason and logic here. Carry on.

 

 

 

 

 

 

Won't even read it, eh?

 

 

 

 

[rocknroller]

Hey, thanks to all who replied; I found the info very "enlightening" to say the least. I'm really not the simpleton I made myself out to be originally, just not that adept at electronics and soldering since I never really have occassion (nor do I really want to) do this sort of stuff. You know how it is when you don't have the right tools for the job to begin with. Not that a soldering gun and some speaker wire is all that expensive, but I would probably never end up using it again. When it comes to amps, most of my past "problems" were way beyond my capabilities to even attempt to repair them myself. Adding the second jack is pretty basic, and I will probably end up doing it. I wanted to use the Epi stack last Saturday night at a gig, and didn't get a chance to add the jack so I was going to just go with the Y-adapter since I had been using the two cabs with that for several days without any problems at all. As it turned out, because of space limitations, I had to set up in front of our keyboard player and didn't want to put that stack in front of hime so I ended up using my Peavey Classic 30 instead. As a side note: the epi cab is a perfect extesion for the Classic 30 since it is also 16 Ohms and already has a jack for an extension cab. When you plug a 16 ohm extension into the jack it automatically changes the load to 8 Ohms. I will get around to soldering the second jack to the Epi cabs since this is probably the bes way to go long-term, but like I said; the $5.00 gold-plated y-adapter plugged into the 8-ohm output with each cab attached seems to work just fine for now. I actually left the amp on my accident for 2 days last week with the volume knob turned up to ~ 4 or 5 and I didn't notice any excess heat build-up and the adapter and cables were not even warm to the touch!

Anyway, thanks all for the great replies.

 

Fred

[Jan Vigne]

When you start drilling to add that jack, make sure the amp is powered down and unplugged.

 

Good luck.