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Peavy prowler?

Started by 9Lives, June 27, 2012, 03:31:43 AM

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9Lives

on todays truck driving adventure I stumbled on one of these amps on craigslist for 350. I went by they guys house and both jacks were all goofed up so I offered 150$ and the guy sold it to me. Kind of a gamble but I brought it home and took it apart and it was just a loose jack.. Shew.. Score! The clean channel is amazing as I've read other reviews but the od channel just wasn't what I was hoping out of a tube amp. That being said who knows how old these tubes are, or if they're still biased correctly. The amp sat for 6 yrs.. He said. It's got 3 12ax7 and 2 6L6. I don't care for the tone stack on the channel either. So would it be a big difference to get a new set of tubes and bias? Or if it's playing should I leve it alone? Also is it possible(worth it?) to figure out away to add a gain stage to the preamp? That should give it a swift kick in the ass you think?

culturejam

It's probably cathode-biased, so you won't really need to re-bias if you change tubes. I'd suggest JJ since they are new-production, very reasonably priced, and generally sound fantastic.

But from what I've read online, the dirty channel is kinda fizzy. Could be a great platform to do some mods, however. For $150, it's not a huge gamble to monkey around in there.  :)
Partner and Product Developer at Function f(x).
My Personal Site with Effects Projects

9Lives

JJ is the brand? And your dead on the money. I wanted this amp for experiment purposes. I've wanted a tube amp for years and just never did it. When I started building this stuff it started to become a must as I'm LOVING messing with amps. I didn't wanna pay out the ass for somthin I could possibly mess up and peavy is a pretty solid universal design. Mod central. Now I gotta figure out what will help it.

mgwhit

CJ, are you sure this is cathode biased?  45W sounds high for 2 cathode-biased 6L6s.  I think it's fixed bias without any adjustability.  Peavey "plug-and-play technology" is what I read somewhere.  There appears to be an adjustable bias mod out there.

Also it looks like the Lead channel might have silicon diode clippers in it.  There's your "fizzy".

culturejam

Quote from: mgwhit on June 27, 2012, 02:15:33 PM
CJ, are you sure this is cathode biased? 

Definitely not sure. That's why I said "probably".  ;)

Either way, it won't *require* a complex rebiasing if the tubes are swapped (for the same type).

You're likely right about the diodes in the preamp. I have a Triumph 60 that has series diodes (which acts sort of like a noise gate), but it actually sounds really good when driven hard.
Partner and Product Developer at Function f(x).
My Personal Site with Effects Projects

atreidesheir

As long as you get power tubes tested for average distortion you should be just fine without modifying anything.   


I had an evil Twin long ago.  The clean channel was awesome and got very dirty when turned up, if you could stand being in the same county with it.  The lead channel sounded like moldy ass.  It was a pedalboard special. 
Technically we are all half-centaur. - Nick Offerman

9Lives

ok if I swap tubes do I have to get matching sets? 3 preamps.  JJ offers a High gain tube 12ax7 I'm about to pull the trigger. Just need to know if they should match. If I mod the overdrive channel I want some dramatic results. Not much info on this amp out there.

stecykmi

you don't typically need to match preamp tubes, just power tubes.

mgwhit

Yeah, preamp tubes (typically 12ax7s) don't need to be matched/balanced at all, but you will need a matched pair of 6L6s. 

Some companies will sell matched phase inverter tubes -- typically 12ax7s that they've tested and found balanced sides (12ax7's are dual triodes, kinda like two tubes in one) -- and the debate rages about whether or not that makes any difference.  Some people feel like mismatch in the phase inverter tube yields better sounding distortion -- kinda like asymmetrical clipping in the pedal world.

(Personal opinion: I would pretty much guarantee that you don't have an album on your shelves that was made before 2000 that features amps with matched-side phase inverter tubes.  Hendrix, Page, Beck, Clapton, etc., were not asking their techs to sort tubes for their phase inverters.  In fact, I'd be tempted to believe you probably don't have an album on your shelf at all that features a matched-side phase inverter tube.  I won't call it snake oil, but I think it's more marketing than anything else.)

9Lives

very helpful so if I just get high gain 12ax7 and matched,balanced and high gain 6L6.    Also I put ROG tonemender in the effects loop along with arbon copy and bloviator and it polished up the overdrive. Fk amazing!!!!!!!!! With OD808 pushing it. Yummy it's like the sound I've always dreamed of and built countless pedals to obtain. Any recomendation on od pedals for bedroom volume.. That's my only gripe is the gain on all my pedals sounds funny at low vol.

culturejam

Yeah, get the matched 6L6s. The JJs are cheap and very nice.

You might also consider, in the long term, making the bias resistor changes necessary to run EL34s in there. I think that would be bitchin. Usually a PT/OT pair that runs fine with 6L6 will also work with EL34s (and some other octals as well), but you'll want to do some research before setting out on that. You really shouldn't listen too much to me on specifics, as I know *just* enough about tube amps to be deadly.  ;D
Partner and Product Developer at Function f(x).
My Personal Site with Effects Projects

9Lives

LOL that usually produces best results right? What would that change? Is that a bigger power tube?

alanp

No, just different. Marshalls use EL34's, Fenders use 6L6's, and they contribute to the 'sound' of the amp. Especially when overdriven.
"A man is not dead while his name is still spoken."
- Terry Pratchett
My OSHpark shared projects
My website

9Lives

ok so 6L6 Bright and sparkly, EL34 deep and warm?

alanp

The tonestack also plays a huge part in the preamp.

http://thetubestore.com/accessories.html should be some links to reviews here for you.
"A man is not dead while his name is still spoken."
- Terry Pratchett
My OSHpark shared projects
My website