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Stock 12AX7's?

spaaarky21

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RSDx

RSDx

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Can anyone tell me (off the top of your head) what model of 12AX7's Epiphone uses in their amps? I assume it's Sovket like everything else but what model? I have a BC30 but I assume they use the same in all their amps.

 

- Brandon

I picked up my EVJr used, it came with beat Sovteks (it's an early V2, so don't know that they ship with now...) ..... the EL-84 rattled like crazy and the 12AX7 was horribly microphonic - I replaced 'em with JJs and pitched the Sovteks, so - that's as detailed as I can give ya.
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spaaarky21

spaaarky21

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I picked up my EVJr used' date=' it came with beat Sovteks (it's an early V2, so don't know that they ship with now...) ..... the EL-84 rattled like crazy and the 12AX7 was horribly microphonic - I replaced 'em with JJs and pitched the Sovteks, so - that's as detailed as I can give ya.[/quote']

 

More than anything, I just wanted to avoid having to take the back off my BC30. :- Those things are built like tanks. Sovtek makes at least three models of 12AX7. Some are better than others. I was thinking about replacing the 12AX7's in my amp with some Tung-sols but want to make sure it would be better than what I have now. I assume the OEM tubes are the cheap ones.

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Bakz

Bakz

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Every one I've ever worked with came with Sovteks stock. I've gotten good reliability out of Sovteks, using them in several applications (not just VJrs). They do sound sterile, but are hiss free and sound better after breakin. The thing is, the EL84s don't seem to make a big noticeable difference what you use, but the single endeds do wear out faster than the preamps. The preamps are just the opposite, better wear and tear, and tons of difference, still I wouldn't waste $$ on vintage glass. The JJs, I've used lately are quite good.

 

In my modded ver 2 heads, I use a 5751 GE MilSpec and a old Curtis Mathes el84. It has Sojo caps, some tone mods with a MM minichoke, and a Hammond 125ESE OT. Its been rebiased. I call it Texas. It likes all kinds of pickups but loves P90s.

 

The other one I use an old Sylvannia 12AX7R refurb, and a JJ el84 it has a choke also, a bitmo gain mod, with the stock OT. It likes humbuckers.

 

Save your money, check out the JJs. Experiment with the 12AT7s (smoother), and 12AX7s more gainful.

 

The BC30s are similar to the old Electras. Try a 12AT7 in V1 and a 12AX7 everywhere else.

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Steven Lister

Steven Lister

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To be sure of brand/model, you're going to have to pull the back on the BC30. Epi seems to put in whatever they grab out of the box on-hand as the amp rolls by on assembly. That said, if this is any help...

 

Both of my VJr. V3 heads came with Electro-Harmonix 12AX7EH pre-amp and Sovtek EL84-6BQ5 power valves.

One was made in '07 the other in '08. For more headroom I upgraded to TungSol reissue 12AX7/ECC803S gold pin and JJ EL84. I am thrilled with the results, but I am still going to try a 5751 one of these days just to compare.

 

I highly recommend buying from a reputable source and one that is willing to provide info. to taylor-fit your exact needs -- there is considerable variation in valves wearing identical number tags and good vendors test and know from the numbers which is higher gain, etc. Virginia Tube Audio (online, prompt, knowledeable) has always come through for me (price and selection) but there are other good vendors out there.

 

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

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Bakz

Bakz

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Both of my VJr. V3 heads came with Electro-Harmonix 12AX7EH pre-amp and Sovtek EL84-6BQ5 power valves.

One was made in '07 the other in '08. For more headroom I upgraded to TungSol reissue 12AX7/ECC803S gold pin and JJ EL84. I am thrilled with the results' date=' but I am still going to try a 5751 one of these days just to compare. [/quote']

 

You got the right idea. The 5751 is just a tad greasier than 12AT7.

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twanger

twanger

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Hey spaaarky21! Here's the lineup in my BC30:

all 12ax7 = Electro Harmonix

both 6L6GC = SovTek.

 

Nearest I can figure using the dates found on components inside the amp was made very late in 2006 or early 2007.

 

In triode (15 watt) mode channel 1 on the amp really sounds great. Hitting SRV tones for songs like "Cold Shot" is just too easy. Unfortunately, there is a lack of touch sensitivity. In fact, just the opposite is happening like a small delay. Channel 2 sounds rough and edgy in an unpleasant way. Almost as if it's out of balance somehow.

 

In pentode (30 watt) mode the 12ax7s are rough and edgy in both channels. Again sounding almost unbalanced. Perhaps this is a clue to check the bias.

 

I have been hopping around the interweb checking out all kinds of reviews, hints, tips and advice on tubes, speakers and so on to improve the sound/performance of tube amps. I want to have some sort of plan in my head before I go plunking down my hard-earned paper on on stuff to improve my amp. It's shaping up to the following:

1) replace the tubes. A lot of folks swear by EH tubes. However, the new crop from the last couple of years seem to cause some to swear at EH tubes. Groove Tubes offer checked and matched tubes which is important for the output tubes in a push-pull configuration (class A/O:) like in the BC30. They also offer some very interesting information on preamp tubes that is well worth considering. Based on all that I've read so far I'm going to go with the Groove Tubes as a starting point. Right now I'm shopping retailers.

 

2) replace speakers. The Lady Luck (Eminence) speakers in the BC30 do sound really good at low and medium levels. At high levels they do not sound so good. I'm going to hold off on changing these until after I change the tubes because they do sound good at lower levels and I'm hoping they'll sound better at high levels after the tube change. If there is no improvement then I'll start shopping speakers. Another member here, K.E.B. I believe, started a thread about speakers. Some very interesting comments in that thread. I must confess that I'm NOT interested in pursuing or achieving a "British tone". I want more of an American "blues tone". Of course, the BC30 is more of an open-back style cabinet (semi-open back?) and information here is very limited. There's all kinds of opinions and personal preferences and it's a lot of work sorting through all that but I think I've got a good starting point in at least avoiding "British tone" speakers.

 

3) circuit mods. There's another thread on this forum about modding the BC30 here: http://forums.epiphone.com/default.aspx?g=posts&t=6812. Lots of good info in that thread. This will be the last step if tubes and speakers don't provide what I'm looking for in this amp. I can do r&r (remove & replace) stuff but I don't really understand the interactions of components in tone circuits so I figure before I turn into a mad scientist making a "Frankenamp" I'll deal with the common mod routes of tubes and speakers first. I will note, however, that the BC30 schematic in some areas seems more complex than other amp designs. I noticed the input resistors are a lower value than the more common 68k ohm used in many classic amps. I may decide to change these resistors also.

 

I'm convinced that there are many more great tones to be found in this amp and I'm going to try to dig some of them out.

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