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Re: looking for an amplifier

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12/14/1997 4:14 AM

Re: looking for an amplifier

John:

>>>I have always thought the Peavey overdrive is too harsh sounding.<<<

    Have you tried out different tubes for your Classic 50? Peavy uses a cheap Chinese 12AX7 that is very harsh sounding. I haven't gotten around to retubing my C50 yet, but I've gotten really nice sounds out of my Classic 30 by using a Sovtek 12AX7WBT+ for V1 (sounds like a vintage Telefunken!) and a 12AX7WB for V2 (not quite as much gain as a WBT+). V1 is used for both "channels" as the initial and final preamp stages. V2 adds 2 additional gain stages for the overdrive mode.
    For the driver tube V3, I found that the stock Peavy tube worked very nicely, at least until I tried out a Golden Dragon 12AX7- very clean, very transparent, and a bit more gain than the stock tube. I think that in an amp like this, the driver tube should not mask or color the tones generated by the preamp stages.
    BTW, I did some mods on my Classic 30 replacing the tone caps and boost caps. By replacing the .022uf bass cap with an Orange Drop .047uf I got much better bass response. I plan to add a second master volume control (a dual 500k pot at the input to the power tubes) to my Classic 50 and will probably upgrade the caps at the same time.
    While I wouldn't recommend a stock Classic 50 for this thread, I was wondering if you have tried retubing your amp. One thing that I noticed was that if I put in 3 of the same preamp tubes, it exaggerated the tonal characteristics (and limitations) of that particular type of tube. By mixing and matching different types, I came up with a combination that works very well for me.

Steve Ahola

12/17/1997 8:41 AM
John D.	I read your mod cover to cover and can't wait to give it a whirl. Even though I am near a city, Philadelphia, you can't just walk into a music store and find tubes. More often than not all they carry are Groove Tubes. Where do you get your supplies from?

12/17/1997 11:51 AM
Jerry	Tubes can be gotten from www.angela.com and Antique Electronics in Tempe, AZ. They have a website but I can't remember it right now. Prices are way resonable and just as a note DON't buy Groove tubes. They are a remarketer and they jack the prices way up. Jerry

12/17/1997 12:07 PM
Doc	John: I live in NE Phila and I stock tubes for repairs. E-mail me directly for telephone #. If you need tubes in a pinch, like on a weekend or evening, I'll usually have them. Doc

12/18/1997 2:35 AM

John:

    Antique Electronic Supply has the Sovtek tubes at reasonable prices. The Golden Dragon drivers are harder to find- Torres Engineering and Griblin Engineering in CA have them for about $13 or $14 each (but the stock Peavy works fairly well for the driver).

    The OD channel on the Classic 30 is still a bit harsh until I kick in the modded boost switch (.001uf instead of .047uf(!)). The Classic 50 doesn't have that boost switch (although most of the circuitry is very similiar). I just noticed that the output from the 1st preamp stage is split to both channels, using a .001 cap to the clean channel and a 470pf(!) cap to the OD channel. I'm definitely going to try upping the OD coupling cap to at least 750pf or maybe even 1000pf(=.001uf). I've got some silver mica caps coming in from AES (thanks for the tip, Doc!) at a fraction of the price that Torres is selling them for.

    I'll keep you posted on what I figure out for the Classic 50.

Steve Ahola

12/26/1997 8:23 PM

John:

    I finally got around to retubing my Classic 50 and it gets some really nice sounds now. The Golden Dragon tubes are hard to find (i.e., Torres and Griblin Eng.), but many music stores carry (or can order) Ruby Tubes and their 7025STR works almost the same as a driver tube. The stock Chinese 12AX7 works pretty good, too- it's the combination of Sovtek 12AX7WBT+ as V1 and the WB as V2 that gets a really good sound in the Peavy; the driver just needs to be clean and powerful without adding its own coloration.

    As for mods to do to the Classic 50, replacing the tone and coupling caps will enhance the tone without altering it too much. It doesn't need as much "help" as the Classic 30, which is unusual because the circuits are so similiar. It could be the larger output transformer that gives it a fuller sound, even at the same volume levels as the C30.

    I'll keep you posted as to what mods I end up keeping.

Steve Ahola

1/2/1998 2:13 AM

John D.

I finally got around to changing out some of the caps, etc., on my Classic 50 and it sure sounds sweet now! I posted text instructions on my web site tonight (a drawing of the component locations will be posted in a day or two):

http://www.geocities.com/BourbonStreet/Delta/3281/C50_mods.htm" target="_blank">http://www.geocities.com/BourbonStreet/Delta/3281/C50_mods.htm">http://www.geocities.com/BourbonStreet/Delta/3281/C50_mods.htm

Steve Ahola

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