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Epiphone BC 30 Valves


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Good evening, and apologies if there is already a thread about this, but I couldn't find it. Please feel free to move it.

 

I thought it would be useful to start a thread of people's trial and error with this amp regarding replacement valves. I admit, to help me.. but also to help others that I'm sure are in the same frustrating position.

 

I'm thinking of upgrading mine because I find the second channel a bit weird, I can't quite put my finger on what it is. It just doesn't sound quite right with the gain pushed up. Maybe it just sounds muddy? Anybody else think that? That clean channel sounds amazing though.

 

Anyway, here are my replacement valve choices.. 5 x JJ 12AX7 2 x Tung Sol 5881 and 1x JJ 5AR4/GZ34.

 

Mine came stock with 5 x EHX 12AX7 2 x Sovtek 6l6WXT and some un-branded 5AR4 rectifier.

 

I am right in thinking that this amp is cathode biased and I won't need to re-bias providing I put compatible valves in there, which I am doing as far as I know?

 

Just so people can compare and gather ideas...

 

1) Has anyone had any particular success with altering the (quite) bright tone by replacing valves in this amp?

 

(I don't find it as bright as some say, and I am reluctant to cut caps as I like having the treble around 2/3 or higher with humbuckers. Granted, with a strat.. the treble on mine doesn't go any higher than 1/3).

 

2) Which valves seem to work well, and which don't?

 

3) Slightly off topic, but has anybody tried different speakers? If so, which worked best? Also, has anybody tried using an extension cab with this amp? I'd love to know what it sounded like hooked up to a 4x12!!

 

Thanks in advance for sharing your blood sweat and tears!

 

Danny

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Hi Danny,

Glad to see you've got onto the BC30 train to tone nirvana, I think you'll enjoy the ride!

 

There's been a massive thread going on for a long time now here: Blues Custom Mods

 

It seems there's a lot of simple mods, valve selection and eq tips that may help you find 'your' tone, but it's at least 7 pages long. This new thread might be a good place to really tidy things up. Maybe even post audio clips?

 

Andy

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Ok, that's a good idea Andy.. let's tidy things up.

 

So, new questions...

 

1) What valve combinations work best for you, and why? What kind of tone do they produce and what sort of music are you playing?

 

2) What mods have you tried and what were the results? No need to go into detail about the mod itself, but try and give people a general idea so they can attempt it themselves.

 

3) Any EQ tips? Post your settings here.

 

4) What pedals have you found work well with the amp, and why?

 

5) Post some sound clips to show different tones and the versatility of the amp. Or even better, a video demonstrating it.

 

Try not to get into a discussion with each other on settings and so on, let's just have this thread as a list of your own improvements and your thoughts. But, if you feel it is relevant then go ahead..

 

I haven't modded mine yet, I'm not sure whether I will or not. I'm waiting on a new set of valves to begin with. I find the tone extremely usable and I have not had so many 'bright' issues as many of you. I like the EQ so one thing I can post are my EQ settings..

 

All on independent and 30w Class A/B - I don't like the way the treble and mids interact in the interactive setting

 

Single coils - Channel one.. Treble 1/3 or a touch more - Mids 2/3 or more - Bass 2/3 Channel two.. Drive 2/3 - Mids 2/3 - Treble 1/3 or a touch more - Mids 2/3 or more - Bass 2/3

 

Humbuckers - Channel one.. Treble 2/3 - Mids Cranked - Bass 2/3 Channel two.. Drive Cranked - Mids 2/3 - Treble 2/3 - Mids Cranked - Bass 2/3

 

I get a nice warm, but chimey and sharp clean sound with both guitars that way, and I get a decent enough classic rock sound through the drive channel. I play mainly classic style guitar with a twist of the modern. My band plays all original material, no covers.

 

Sorry for the vague 2/3 1/3 and so on, but I often change it slightly within that zone. The EQ is extremely sensitive to the slightest of change, I find anyway. Bass never goes more than two thirds on the drive channel, I find it gets boomy and muddy. Something I hope to resolve in these coming weeks.

 

I probably won't get my valves for a week or two due to shortage of funds, but I'll be watching the thread and will post my results. I'll try post some before and after valve swap sound clips as well.

 

 

Danny

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Anybody?!

 

Anyway. I've decided to go for the cap mod.. one by one, as soon as someone tells me how they do it. I'm not sure whether to cut one leg, or both from the cap.. or de-solder completely. This is my first outing as an amp 'modder'!

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  • 1 month later...

Svetlana =C= 6L6GC <- big open sound

Sovtek 5AR4 <- the stock Chinese bottle is rubbish.

Mullard-clone ECC83 (except reverb bottles are the stock EH) <- no, they're not the same as real Mullard, probably some super-Sovtek types.

 

Others to try

Sovtek 6L6WXT+ (oh, they're the stock ones, not too scruffy though)

NOS GE-JAN 6L6WGB <- cute, tighter than Svetlana =C=

JJ-Tesla 6V6GTS (6V6S) <- bright and clear - appears to be a 5881-type with low current heater, indestructible.

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Bog standard EH 12AX7's - Sound fine and no need to change

 

Matched pair of 1961's RCA Blackplate 6L6's - Warm and responsive with controlled, progessive breakup

 

1959 Mullard GZ34 - Hard at clean levels with a nice bounce as you push things

 

*Note* All the above is totally subjective and probably won't stand up to your opinion but I don't care!

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  • 4 weeks later...

Bog standard EH 12AX7's - Sound fine and no need to change

 

Matched pair of 1961's RCA Blackplate 6L6's - Warm and responsive with controlled, progessive breakup

 

1959 Mullard GZ34 - Hard at clean levels with a nice bounce as you push things

 

*Note* All the above is totally subjective and probably won't stand up to your opinion but I don't care!

 

wiggy,

 

Where did you get the RCAs and Mullard?

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I gave up looking on ebay as prices for vintage valves are frankly ridiculous. What I did was spend some time searching google using various combinations of terms which included 6L6, 5AR4, GZ34, etc. Took a few hours of searching over several days but I eventually came across one guy on a small Canadian vintage radio forum who was selling a pair of NOS 1961 dated RCA Blackplates for $50 Canadian plus postage. A quick email later they were mine.

 

I found the GZ34 here in the UK by the same method - Picked up it up along with a mid 60's Zaerex Branded GZ34 for £25.00 inc p&p from an ad on a vintage radio forum.

 

I've found that there are still genuine bargains to be had out there in internet land if you're willing to take the time and go off the beaten track to look for them (internet equivalent of junk shop rummaging!). Other good finds I've turned up were a pair of BBPros @ $85.00 the pair in p/p from the US and a 57 Classic for £25.00 plus £2.50 p/p here in the UK.

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Nice! Those are some sweet deals. I know an old radio guy who has hundreds of tubes up in his attic. I met him this summer through an old friend. He tossed me a few tubes on my way home.

 

1. National Electronics EL-34 (newish looking tube)

2. Raytheon 6V6GT (this one will fit in my amp)

3. GE 7 pin 6V6GT (not sure why it's 7 pin instead of 6) anybody know?

 

Anyhow, He gave me 2 EL-34s. I guess I lost one in transit. The 6V6s I haven't tried yet. I'm very happy with my current tubes. I'm using a NOS JAN 6v6GT, a JJ/Tesla Rectifier and a Tung-Sol 12AX7. I keep telling myself I'm going to try the older 6V6s. Might find some happy notes.

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  • 2 months later...

IMO the Mullard GZ34 rectifier (unlike the ECC83 and EL84) is not a special valve, a Sovtek 5AR4 is more than adequate, and a lot cheaper.

 

It is very hard to beat the Mullard ECC83 when it comes to 12AX7, Telefunken ECC803S come close and JJ do a good low-noise clone of that one in their ECC83S (not! their ECC803S). Some of the ECC83/12AX7 from Reflector (mostly Sovtek + some other brands) are modelled on the Mullard and are very good they are too.

 

For the OP bottles there are a number of good NOS 5881/6L6 available as well as new builds. The BC30 is cathode biased aka "self-biased" so one may swap bottles with some impunity: it will even take EL34 and KT66.

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I found an Amperex Bugle Boy 5AR4 in an electronics storage closet two days ago. I asked the engineer if I could have it and he said fine so long as I wasnt going to try and make my car payment with it. When I told him my intentions he said:

 

"I can see changing the preamp tubes to get different tone but changing out the rectifier is like putting a new gas pedal in your car and expecting it to go faster."

 

I changed them out anyway, and upon doing so I felt that the amp gained a little more clarity and perhaps warmth, and less buzzing at high gain, but I couldnt swear to it.

 

Thoughts?

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I found an Amperex Bugle Boy 5AR4 in an electronics storage closet two days ago. I asked the engineer if I could have it and he said fine so long as I wasnt going to try and make my car payment with it. When I told him my intentions he said:

 

"I can see changing the preamp tubes to get different tone but changing out the rectifier is like putting a new gas pedal in your car and expecting it to go faster."

 

I changed them out anyway, and upon doing so I felt that the amp gained a little more clarity and perhaps warmth, and less buzzing at high gain, but I couldnt swear to it.

 

Thoughts?

 

Replacing the chinese rectifier with anything-else is like putting a gas pedal in the car.

 

Perhaps it is more akin to high or low octane fuel, some provide more or less volts than others depending on how efficient and smooth they are. A rectifier can only alter the sound of the amp be changing the HT (B+) voltage. If they are the same spec i.e. 5AR4/GZ34 that will not be by much. One other factor is how smoothly they provide the voltage, they don't switch on until they get to a certain voltage in the cycle, and whether they clip-off the top, this makes the task of the smoothing caps more difficult. A good rectifier does not have any problems, either it works or it doesn't: fit and forget. Don't waste money on NOS, nothing to be gained here.

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