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Jazzric

Tube warm up.....

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Sorry to ask this dumb question but I'm new to Tube vibe and ....well when I get home from work the first thing I do is ice the glass... then power up my studio and Now my EVJ then put out family fires then back in the studio, jam with my amp, then try to get some recording work done and sometimes I'm NOT using the EVJ at that time...should I turn it off to save tube life or just leave it on..or does it matter...and if I turn it off..do I have to let it warm up again.....

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start and stop is harder on tubes than just sitting there.

 

Unless it was like an hour or a little less, I'd leave it on.

 

Hell they like 20 minutes!

 

TWANG

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Average tube life should be around 5000 hours, but the stock VJr's biased too hot, and will chew through power tubes a lot faster. I've had a couple of el84's last as little as a week and others that died within a month in the stock amp. That went on until I learned to lower the plate voltage and cool off the bias. My two earliest turret board amps have been running the same JJ el84 power tubes for over two years now, and they're left on, a lot. That ain't too shabby. In fact, one of those amps was ON for an entire 24/7 last week while burning in a cap for a friend, and now they'll both be on for another week to burn in a complete upgrade set of tone caps.

 

Gil...

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cgil..I aint goin to lie...the "lowering the plate voltage and cool off the bias" went right over my head..but I did catch the JJ el84 thang...I'm thinking of checkin those out...I read a lot of good things about those...

Thx for the info..

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cgil your post raises this VJr. voltage question: When you re-bias plate voltage to the lower/correct level, do you add more warm-up time to compensate? How much time if any?

 

Hit every BLUE NOTE baaaby..., I'm going to play on:-"

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Even when my VJr's were new, they all sounded better after 15 minutes warm up time. That hasn't changed.

 

You should've heard my 6U8 > 6AQ5 amp when I first fired that one up. It gargled for the first 5 minutes of its life. Seems that's common to those oddball 6U8 tubes. Even 6SJ7's crackle for a couple minutes. They both sound like a bad tube at first until they're burned in. And even after that, they still sound better after 15 minutes of warm up time.

 

It's just the nature of tubes.

 

Gil...

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You know, after all these years, someone should have applied high tech to tube components. My original Electronics Tech training was in tube theory (Yes, I'm an old guy) and the last part of the course was, oh by the way here's some new-fangled stuff, transistor theory. I learned LSI and digital on my own and have worked as a Tech Rep for 35 years in today's electronic world.

 

We still use filaments to heat a cathode, a control grid, a screen and/or supressor grid to control the emissions, and a plate to provide the varying output. I guess there's no better way to get the tube sound without 50 year old technology.

 

The difference, imho, is that tubes have a slow response time to a given input signal, whereas transistors and integrated circuits are speed demons. We like the feel of tubes and think transistors are cold audio processing devices. I remember when transistor amps replaced tube amps for "hi-fi" audio. Cymbals suddenly became clean and the whole vinyl world sounded better through speakers. Frequency response widened and we suddenly experienced music with almost no high end roll-off and the audio world was listening to 20hz to 20k hz music with .1% total harmonic distortion and +-3db down points.

 

About that time, I traded my tube Fender Bandmaster for a Peavey Musician with a 4x12 cab. Boy, was I impressed! Instant on, great sound, tight lows, and it ran cool! You didn't have to take the tubes to the drugstore to check them periodiocally and the life of the transistors was 100,000 hours. I never looked back until recently. Now I am looking at tube amps again.

 

The world always seem to come full circle at some point...

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There are those who believe that technological perfection peaked in 1965. From there, we've become more refined and sophisticated, but not necessarily better, and you can look at just about anything produced at that time and compare it to today's items, and see the point being made. Guitar amps and cars, in particular, but look at some of today's appliances too, for instance. What utter crap, compared to what was being produced 44 years ago.

 

It's not just the workmanship, although that's suffered terribly with the advent of robotic workers. It's the stuff that our stuff is made of as well. In all of the "advancements," we've gone away from quality materials throughout, and opted for crap components and materials, in order to shave costs. It's a damn shame.

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funny how we've gone from should I leave my tubes on to workmanship of 40yrs ago.

 

Well M-T back in the late 60's cars used to be owned for no more than 2yrs or 60,000 miles; now your typical import car goes between 180k to 300k miles your 65 Impala never could do that, plus brake from 60mph in 45 feet and coner at .85g's... although the steel they were made of back then was quite solid.

 

Now the tubes, definitely not made the same just do to cost cutting.

 

back to the tube warm up thing.. It's a tube amp, just like light bulbs you better have a few spares and since we're talking a VJ with only 2 tubes.. well 3 sets at $28 ain't going to hurt you at all.

 

 

btw I play better when I'm warm, drive better when I'm warm... wish it wasn't -24 with the wind right now....

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OK, on a somewhat related note, how about new tube burn in ??? ...... been a LOOOOONG time since I owned a tube amp - do new tubes have to burn in before they sound "right"....and is crackling/squealing "normal" for new tubes before burn in or did our local mom'n'pop shop sell me bad tubes (they are Fender branded, fwiw.....only tubes they seemed to have....) ??? It's literally been 30 years since I replaced an amp tube, don't recall that issue....but I AM old, now, so.... bad memory, perhaps:-k I've since put the previous old tubes back in my EVJ, and all is well.......just wonderin' if these new ones are bad from the get go or if I need to burn them in for some length of time. Might it be any more reliable to order online somewhere ?

.....a couple of JJs or something ??

 

Thanx, all y'all

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back in the late 60's cars used to be owned for no more than 2yrs or 60,000 miles; now your typical import car goes between 180k to 300k miles your 65 Impala never could do that

Actually I personally saw it happen many times. I used to work as a grease monkey in a previous life, and can't even tell you how many times I saw older vehicles with a bazillion miles on them. I used to be astonished by it myself, until I started putting those kinds of miles on my vehicles as well. It really wasn't all that uncommon. It was just a common belief that it wasn't possible.

 

plus brake from 60mph in 45 feet and coner at .85g's

Disc brakes were around back then, as was front wheel drive, fuel injection, automatic headlight dimmers, and radio scanning.

 

although the steel they were made of back then was quite solid.

The steel hasn't changed much, but the gauge certainly has. The problem is that, along with that lighter gauge metal also came lightweight plastics, that simply don't fare all that well on vehicles, in all circumstances. More evidence that technology hasn't necessarily improved our lives all that much since '65.

 

back to the tube warm up thing

Yeah, I did get a tad off topic there...

 

Tubes warm up sufficiently to play through within a couple of minutes. Leaving a tube amp running idle for longer than 20 minutes or so can lead to overheating, so it's best to shut er down when you're walking away to do something for that amount of time.

 

The thing that bugs me about the stock Vjr, and other similar amps w/o tube rectifier, is that there's no standby switch. It's not a big deal on a SE amp that's tube rectified, but w/SS rectifier, you're throwing a helluva lot of current at those tubes when you flick the power switch on. Cold starting tubes that way causes a lot of wear and tear, but, as pointed out, there are only two tubes, and they can both be had for cheap, so I suppose it's not the end of the world that these amps are designed to chew them up faster than they otherwise would.

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on the one hand. the toyota has 183,00 on it and I can't believe anything that beat up and abused starts first time every time year in and year out.

You can have my kids chrysler and my gm for my first car a 1950 chevy, even up trade.

And I bet with few upgrades, it'd last as long as anything. though maybe not perform as well.

 

plus, I could put a wrench to it, or even a stick! *esp. in the linkage, but also makes for a nice cruise control stuck between the handbrake and the gas pedal*.

 

the only think I can do to any of my cars now is swear at them.

 

I bet if you released the 32 ford with or without fenders, you'd sell them all. all you'd have to do is upgrade the engine and the brakes and make sure everything was wrenchable.

 

TWANG

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twang.. as long as they didn't us GM's current electrical systems.

our '90 Cav lost its oil pump right at 125k miles which took the main bearings with it. The '90 Toyota got to 230k when the head gasket went.

we then leased a '02 Cav which promptly blew power window motors every single winter, ever single window one after another, also blew controls to the fan when ever it felt like... end of lease... end of car..

Have an 06 Toyota van... thank you little Japanese man.. works like a charm.

 

Sometimes I think about that little Japanese man that makes everything that's in my home

Sony, Sanyo, Hitachi, Toshiba, my stereo comes from Japan.

Thank you Ankyo, Onkyo, and Akki it’s all made by a Japanese man.

Yamaha makes my car, my motorcycle, piano, amplifier and guitar.

They do it so much better; they do it with such ease; they’re the real trendsetters; they’re the Japanese…

 

What does the Japanese man do late night in Tokyo when he’s alone.

He goes out to McDonald’s, in his Calvin Cline’s.

His walkman plays the Beach Boys, His Coke goes down real fine.

Sony, Sanyo, Hitachi, Toshiba, my stereo comes from Japan.

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I guess what I was hinting at in my post about today's tubes still being based on 60's technology is that we still have the same problem. In order to conduct, tubes need to heat up. Hotter bias means hotter tubes. Hotter tubes means early failure. Cool them off too much with a fan and you lower their efficiency! There's no long life solution except to carry a spare set.

 

I still believe that modern tech should be able to design a tube replacement with the same feel and response and overdrive crunch that wasn't so fragile. But, we probably would kick it to the curb and demand our 6L6s and EL84s back (grin).

 

I really was trying to reply to the topic of warm-up, albeit on a tangent.

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ET I just looked around. most of my good stuff is japanese.

My sons chryslers seat heater went out. You have to replace the entire seat.

All the rear heater/ac controls on my gm van went out the same week. driving down the interstate with smoke pouring out my dashboard.

the tercel gets 45mpg, and everything works.

 

 

 

 

Dave. there's an electronic tube... I forget what they're called. Last issue of Premier magazine.

Non glass, at least, look more like caps. supposed to be great....

 

TWANG

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Hotter bias means hotter tubes. Hotter tubes means early failure. Cool them off too much with a fan and you lower their efficiency!

The bias is determined by voltage, current, and resistor values, and the tubes will get as hot internally as they're going to get, with or without a fan aimed at them. Ultimately, the lifespan of an output tube is determined by a number of factors, including manufacture quality, running voltage and current, and how hard the tube is driven (or overdriven, as it were), vibration, start-up process, etc.

 

I still believe that modern tech should be able to design a tube replacement with the same feel and response and overdrive crunch that wasn't so fragile.

There's a company that introduced itself at NAMM this year that boasts a transistor-based plug-in replacement for preamp tubes that reportedly (according to the maker) is equal to glass and filament in all ways except superior in consistency, gain, microphonics, and of course, longevity. A friend of mine writes reviews for a leading guitar magazine, and will be receiving the full set to write a review on. I've been invited for the test driving. Should be fun and rather interesting, to say the least.

 

Bear in mind that JFET and FET circuits already exist that very closely duplicate the sound of numerous preamp circuits. You can buy or build these as guitar pedals that come remarkably close to the sound of a given tube amp's preamp section. Soldano, Mesa, Marshall, Fender, Vox, etc., all have had their preamp sections re-written quite successfully in transistor format.

 

Preamp tubes, however, aren't power tubes, and in particular, aren't overdriven power tubes, and since this is where the real magic of tube amps happens, it's critical that this magic be captured in order for there to be a credible transistor replacement. The problem is that there is a gigantic matrix of variants that play upon those grinding output tubes, while they're producing that magic, and all of those variants haven't even been fully identified yet, let alone quantified, not to mention translated into the mathematical equations that would allow engineers to develop transistor-based circuits to emulate them.

 

This is going to be a long time coming. It may come, one day, but we're laughably far off in computing horsepower and programming algorithms at this point to even come close. I too, believe that it will probably happen, but probably not for another 20-50 years, or perhaps even longer. When they can truly create that output tube magic in a transistor form, we'd be fools to not switch. The only reason we're addicted to tubes right now is specifically because they haven't yet recreated that magic with silicon. The moment they do, all of the God-awful limitations, faults, inconsistencies, and failures of our beloved tubes will be far too much baggage for anyone with common sense and logic to consider tolerating any longer.

 

I really was trying to reply to the topic of warm-up, albeit on a tangent.

Tangents can result in interesting journeys that otherwise wouldn't be traversed!

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I read a white paper written by Hartley Peavey this morning about their move from tubes to transistors and all the struggles they went through to emulate tube feel. You can read it here http://www.peavey.com/support/technotes/hartley/chapter_3.pdf

 

Hartley talks about tube sag at high volumes being a design factor that is controlled by the output transformer. He goes into much of the history of their amp development and R&D work. It's interesting that he talks about solid state amps being transformerless output since they are low impedance stages. I never thought about that, but it makes sense.

 

There are several other papers here. http://www.peavey.com/support/technotes/ I haven't read them all yet, but plan to soon.

 

Heat is our enemy and our friend...

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Hey guys not to drift too far away from post ,But the GM and Chyr.Cars,Trucks have been using imported parts [Alts,wiper motors ,window motors , seat heaters ] [nippondenso, Bosh etc] since the late 80's .The thing is they have not built an American car or truck since then. Parts come from everywhere just relabeled Hench the price increase

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The difference' date=' imho, is that tubes have a slow response time to a given input signal, whereas transistors and integrated circuits are speed demons. We like the feel of tubes and think transistors are cold audio processing devices. I remember when transistor amps replaced tube amps for "hi-fi" audio. Cymbals suddenly became clean and the whole vinyl world sounded better through speakers. Frequency response widened and we suddenly experienced music with almost no high end roll-off and the audio world was listening to 20hz to 20k hz music with .1% total harmonic distortion and +-3db down points.

 

About that time, I traded my tube Fender Bandmaster for a Peavey Musician with a 4x12 cab. Boy, was I impressed! Instant on, great sound, tight lows, and it ran cool! You didn't have to take the tubes to the drugstore to check them periodiocally and the life of the transistors was 100,000 hours. I never looked back until recently. Now I am looking at tube amps again.[/quote']

 

There was an interesting post on here not too long ago where someone had been playing through a PA or home stereo (because it was available to him and he didn't own an amp) and was deciding which amp he wanted to get. Someone brought up an interesting point that you don't want your guitar setup to be hi-fi like a home stereo system.

 

Basically, you want your home stereo to be as hi-fi as possible so you hear exactly what went on at a recording session. But when it comes to making the sound, you really want to add some character. Pickups, amps, tubes, effects, speakers - those are all things that take the tinny, unpleasant sound of a vibrating electric guitar string and transform it into something worth listening to.

 

Exact 1:1 signal reproduction is not something you want in a guitar amp. In fact, I have a solid state practice amp that reproduces sound pretty accurately (super clear, doesn't filter the highs or lows at all, etc) and it makes a pretty lame guitar amp. Although, it makes a great keyboard amp and you can even play the bass through it (my BC30 would roll off most of those lows.)

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There was an interesting post on here not too long ago where someone had been playing through a PA or home stereo (because it was available to him and he didn't own an amp) and was deciding which amp he wanted to get. Someone brought up an interesting point that you don't want your guitar setup to be hi-fi like a home stereo system.

 

Basically' date=' you want your home stereo to be as hi-fi as possible so you hear exactly what went on at a recording session. But when it comes to [b']making[/b] the sound, you really want to add some character. Pickups, amps, tubes, effects, speakers - those are all things that take the tinny, unpleasant sound of a vibrating electric guitar string and transform it into something worth listening to.

 

Exact 1:1 signal reproduction is not something you want in a guitar amp. In fact, I have a solid state practice amp that reproduces sound pretty accurately (super clear, doesn't filter the highs or lows at all, etc) and it makes a pretty lame guitar amp. Although, it makes a great keyboard amp and you can even play the bass through it (my BC30 would roll off most of those lows.)

 

Most hi-fi stereo amps have a large enough output transformer (if it's a tube amp) to prevent sag and the mid-range hotspot when cranked. The SS amps don't sag because OTL SS outputs can keep up with the power handling needs to a point, at which you get harsh clipping. Everyone wants faithful reproduction in a stereo amp, but faithful reproduction sounds lousy with guitar.

 

We all say that we set our amps "flat" and work from there, but flat in a guitar amp is tweaked to make the instrument sound good.

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