I can't answer your questions but I can tell you that the Peavey Envoy and Peavey Studio Pro both use the LM3886.  The very early versions of these models use discreet components in the power section but from about 1999, they use the LM3886.

Grounding definitely is the first suspect. And not just inside the amp, but also at the electrical outlet (or the whole house).

One thing to bear in mind folks is that signal ground and chassis ground are not always the same. If the signal ground is floating above chassis ground, then so is the guitar when it's plugged into the amp, and so are you when you're touching the strings. Hence, shock hazard. 

Phil

10-4 on all Phatt.  I know whatcha mean.

I have a couple of different versions of the Bandit that I fart around with.  Not much money tied up in them and I can get a decent sound with an archtop or a humbucker equipped tele ( I'm at the opposite end of the scale from a thrasher/metal head).  But I do know I could get a much better sound from a Deluxe Reverb or Polytone or an Evans - the Bandit ain't the be-all/end-all by any means.

Despite phatt's criticism, the Studio Pro and it's siblings (Bandit, etc) are considered to be decent sounding amps for this class of amplifier. Surprisingly, some fairly picky jazz guitar players have commented that the Bandit and Studio Pro offered pretty good bang for the buck compared to their high-buck jazz oriented rigs.  Not as good as....but still passable.  And that says something for amp that can be bought for $150 - $200.  These are considered to be good, rugged, reliable amps.  Whether you can get the tone from it that you want - only you can decide.  Heck, people sell Fender Twin Reverbs because the amp didn't produce they particular sound they wanted.  So the fact that the Peavey Transtube's are all solid state doesn't mean diddly.

The Tech 21 Trademark 60 amp (all solid state) is another one that gets good reviews.

Perhaps $300 isn't a "steal" for one of these, but these amps are few and far between these days. It's not like you can pass it up with the idea of just going down the street to buy one cheaper somewhere else.  I have an L9 that is in rough cosmetic condition and I probably paid too much for it based on it's condition.  But it works, it's a unique amp and they're hard to find so I didn't mind.

Anyone have a schematic for Peavey Studio Pro II 112 ? I'm looking for the "Red Stripe" version, made from 2000 to about 2005 or 2006.

Thanks....Phil

Although it is not indicated on the diagram itself, this is supposed to be the schematic for the old 'Orange' Roland Cube 60

Quote from: Enzo on March 13, 2009, 11:50:21 PM
I am glad you fo0und them.

I am sorry I was unclear.  I meant that they would be a likely source, I didn't mean to infer they would list all their parts online.

Understood Enzo.  An no apology necessary.  Thanks also for the B&D link - I was not aware of them at all until you posted.

Is it worth installing sockets on the board for these chips as they're replaced ?  I'm thinking that will minimize repeat soldering operations on the board if the chip needs replacing in future, and the new chip won't see any soldering heat at all.

I too worry about counterfeits. The picture of the chips in the eBay listing showed a chip that was indentical  in every way to the chips in the amp - font, logo, placement of markings. And the ones that arrived matched too.  BUT, there was another eBay listing for M5201A and based on the picture in that ad, I wouldn't touch them : no logo, no notch, no date/manufacturing code, and "5201A" was in the wrong position on the chip.

Quote from: J M Fahey on March 14, 2009, 07:08:35 AM
Hi VA3AUX, just as a curiosity, how much did you pay for them? Are they regularly available? Thanks.

They were around $11 for a sleeve of 10 chips, plus shipping.  There were only 2 or 3 listings on eBay for them.  But that seller seemed to have a supply of them.

I didn't assume Enzo.  YOU suggested it.

Try walking into a Marshall dealer around here to order a chip for an amp.  You get a blank stare.

I just got a sleeve of 10 of them off eBay and they're fine. A no wasted time or gas driving around to Marshall dealers that only know how to order casters or replacement speakers.

Marshallparts.com didn't list any semiconductors on the website so I assumed they didn't carry them.

Since my original post, I ordered a sleeve of them off eBay.  I hope they're not counterfeit.  These chips are not easy to find (at least in small quantities).  I'm in Canada and only one supplier in the country has them.  $15 each and $100 minimum order.  To hell with them.

Anyone know of a good source for these chips in North America ?  I've come up with plenty of large volume suppliers via Google, but I don't a hundred of them.  I've got an offer in on a few from an eBay seller in Hong Kong and that may work out fine, but I still prefer local supply if possible.

Phil

Quote from: GLUGSTER on January 09, 2009, 09:23:46 AM

Quote from: JVandenberg on January 04, 2009, 06:03:30 PM
I  I also have had great luck with Peavey's Bandits. 

Amazing! I thought I was the only human on Earth that likes the Bandit!!

The Peavey Bandit actually has a huge following. Have a look at the number of reviews and responses on Harmony Central for the various Bandits.  There may well be more of those amps built and sold than any other amplifier in history. It's been in their product line for 30 years although it has gone through many incarnations along the way.

I never see mention of the Gibson Les Paul SS amplifier from the very late '60s/early 70's .  Probably for good reason too.  I played through one in a music store in Hamilton, Ontario and this was probably around 1970 or so.  It was a head/cabinet affair and fairly big . I think the power amp was in the speaker cabinet.  I  recall it being very sterile or metallic sounding.  Never saw another one again and I've never heard it mentioned.

In Canada we also had GBX SS amps during the 1970's. I don't think there were any combo amps, just head/cabinet sets. I remember thinking they were awesome looking at the time. They appear on eBay every once in a while.

Another SS amp I'll never forget from the 70's is a Yamaha amp that was like a 4  foot tall pyramid. Sort of like a piece of pie standing upright.

So there's some additional vintage SS amp history for you.

The JRC 4558D chips were used in the old Ibanez Tube Screamers and were considered to be the 'secret' to the tone of those pedals. The chips are still made today but under the company name New Japan Radio. Hype - or not - but there's a belief that older 4558 made by the original JRC company sound different (ie. 'better' - in a Tube Screamer) than the newer 4558 chips made by NJR.  You'll find these chips in a lot of SS amps, such as your Yamaha, plus Peavey, Polytone and many others.
You probably can change the sound of your G100 by substituting different pin-compatible chips. There are higher fidelity chips available. But personally, I wouldn't mess with the already-good sound of a G100.