Peavey Bandit Club

[spangler41]

Originally Posted by strat56

When you mention replacing the op amps, do you mean just replace them with the same model or are there other models I can try? What might be the results with the different op-amps?

A lot of progress has been made replacing the op amps in Peavey SS amps. The 4560 chip is an old design dual op amp and a new generation of high-quality audio op amps is now available. The direct plug-in replacement for the 4560 is the Texas Instruments OPA2134PA, aka Burr-Brown chip. It has better signal to noise and distortion characteristics. I did this to a Music Man amp recently and the improvement was very noticeable. These chips cost about $2.60/each and are available from Mouser.com.

[el cheapo]

Originally Posted by spangler41

A lot of progress has been made replacing the op amps in Peavey SS amps. The 4560 chip is an old design dual op amp and a new generation of high-quality audio op amps is now available. The direct plug-in replacement for the 4560 is the Texas Instruments OPA2134PA, aka Burr-Brown chip. It has better signal to noise and distortion characteristics. I did this to a Music Man amp recently and the improvement was very noticeable. These chips cost about $2.60/each and are available from Mouser.com.

I have a 2008/9 Bandit 112 (Chinese), which sounds pretty good. I replaced the Blue Marvel speaker with an Eminence V128, which helped. Would this amp benefit from the mods you are suggesting?

[Higgs F. Boson]

What exactly is "improved" by swapping the op amps? Does it make the amp more "hi-fi"? Because a stock Bandit is already pretty hi-fi.

[spangler41]

Originally Posted by el cheapo

I have a 2008/9 Bandit 112 (Chinese), which sounds pretty good. I replaced the Blue Marvel speaker with an Eminence V128, which helped. Would this amp benefit from the mods you are suggesting?

I don't know what Peavey is using in the much newer Bandits so I couldn't answer that question. If they are still using the TL072, 4560 or 4558 or one of the older generation chips, I would expect improvement.

[spangler41]

Originally Posted by Higgs F. Boson

What exactly is "improved" by swapping the op amps? Does it make the amp more "hi-fi"? Because a stock Bandit is already pretty hi-fi.

My experience is that the new chip "sounds better". I know that is a very subjective thing but I've been playing a long time and liked the sound. Here is a link to read about the Burr-Brown OPA2134PA op amp:
http://www.futurlec.com/Linear/OPA2134PA.shtml

[Bill Moore]

spangler41, Did you also change the reverb drive op amp? I did in mine, and the reverb is not as aggressive as it was before. If I ever open it up again, I'm thinking of putting a 4558 in there.
I did lose a lot of noise, I really like the sound from the Burr-Brown chips. I also got a deal on a Weber Thames speaker, it has a lot more bottom, and top now!

[spangler41]

Originally Posted by Bill Moore

spangler41, Did you also change the reverb drive op amp? I did in mine, and the reverb is not as aggressive as it was before. If I ever open it up again, I'm thinking of putting a 4558 in there.
I did lose a lot of noise, I really like the sound from the Burr-Brown chips. I also got a deal on a Weber Thames speaker, it has a lot more bottom, and top now!

I will have to pay closer attention to the reverb. I use a Boss GT10 in front of the amp and don't use the amp's reverb.

Regarding the Thames speaker, Weber does not post SPL figures so how would you compare the efficiency of the Thames?

[Bill Moore]

It had a Sheffield originally, and the Thames seems to be louder by a little over 1 number on the gain knob. What is really different is the extended range (high, and low), that the little amp produces. I usually run it on top of a 112sx with a Sheffield, so I guess I still have some of the original sound also.

[el cheapo]

Originally Posted by spangler41

I don't know what Peavey is using in the much newer Bandits so I couldn't answer that question. If they are still using the TL072, 4560 or 4558 or one of the older generation chips, I would expect improvement.

I also have a Peavey Audition 110 that I use for practice. It's an older amp, but I wouldn't mind if it sounded better as well. Is replacing these OP amp chips difficult to do? Thanks!

[spangler41]

Originally Posted by el cheapo

I also have a Peavey Audition 110 that I use for practice. It's an older amp, but I wouldn't mind if it sounded better as well. Is replacing these OP amp chips difficult to do? Thanks!

Hi, I'm not familiar with the Audition. The Bandit and many other Peavey SS amps use the same op amps. They are an 8-pin chip that plugs into a socket. Obviously, you have to remove the chassis to get access to the op amps. If yours are the 8-pin op amps and are in sockets, you can replace them by carefully prying them from the sockets with a small screwdriver or other tool, paying close attention to the dot on one corner of the old chip. You have to be careful when plugging in the new chips to ensure that the dot is in the same orientation as the old one. The socket will have a notch at one end and this is the end where the dot is oriented. The improvement is subtle and favorable, but does not convert the amp into a $4000 model. FWIW, the Eminence Ramrod is the best sounding 10" speaker I have ever heard. I replaced with one in a Peavey Backstage 65 and it was awesome.

[Chilao]

New club pledge here with two Bandits, a 65 and 112 Teal. Straight off I have question for the group. The Teal has a bit of an issue in that it will not produce any sound unless the effects loop is jumpered across with a patch cable or a pedal. I don't think it is supposed to be this way. Any idea what could be going on?

[spangler41]

Originally Posted by Chilao

New club pledge here with two Bandits, a 65 and 112 Teal. Straight off I have question for the group. The Teal has a bit of an issue in that it will not produce any sound unless the effects loop is jumpered across with a patch cable or a pedal. I don't think it is supposed to be this way. Any idea what could be going on?

I have seen several Peaveys with this problem. The RETURN jack in the effects loop is a shorting aka switching jack that disconnects the preamp when plugged into. The solution is to clean the return jack. You have to remove the chassis and carefully insert a nail file or something similar between the contacts inside the jack. Spray with contact cleaner or Deoxit. This usually will restore the connection inside the jack so that it will connect the preamp to the power amp with nothing plugged in the return jack.

[Chilao]

Thanks I will give this a shot.

[BelairPlayer]

Originally Posted by Chilao

New club pledge here with two Bandits, a 65 and 112 Teal. Straight off I have question for the group. The Teal has a bit of an issue in that it will not produce any sound unless the effects loop is jumpered across with a patch cable or a pedal. I don't think it is supposed to be this way. Any idea what could be going on?

Common problem with effects loops. The 1/4" jacks have contacts that are supposed to be shorted together (normally closed) when they are not in use. Your's have either become dirty (oxidized) or damaged (bent/open). Most likely they are oxidized. Try shooting a bit of Deoxit cleaner in there if you have it. If you don't have it, buy some...you'll need it sooner or later with amps. Better yet, pull the amp out of the chassis and spray it directly into the jacks. Then insert/remove the plug repeatedly to work the cleaner in. The jacks are board mounted.

If that doesn't fix the problem, the jacks are likely damaged and need to be replaced. If that is necessary, I'd go ahead and replace them with panel mount jacks and add flying leads instead of the board mount jacks. The jacks are 1/4" normally closed (NC).

[Chilao]

Thanks guys, I much appreciate the diagnosis on this. I'll open her up after work this evening.
One more question, what is the trick to removing the grill cover on the Teal 112? The 65 is held in place with some heavy duty velcro. I don't see any screws and i'm afraid to yank or pry on it too hard.
Thanks again, don't know where i'd go with out this forum resource.

[BigD]

I was just looking at a Bandit 65 on CL for $125. Is that a reasonable price?

[Higgs F. Boson]

Originally Posted by bluesmanmartin

I was just looking at a Bandit 65 on CL for $125. Is that a reasonable price?

I'd say yes. I got my US-made Bandit 112 for $100 but it seems like $250 or so is more in line with the guitar-store price for the older ones.

I played an old Backstage Plus the other day and was floored by how good it sounded. Local store was asking $100 for it.

[LGOberean]

Originally Posted by bluesmanmartin

I was just looking at a Bandit 65 on CL for $125. Is that a reasonable price?

I'd also say yes, but $125 is probably close to the top end of what a Bandit 65 should go for. Maybe you could talk the seller down a bit.

And of course, it depends on the condition. The Bandit 65 is anywhere from 26 to 29 years old, which is getting kinda long in the tooth, even for the rock solid, reliable old Bandit. I'd pay $125 only if it was in top condition, and even then I wouldn't be surprised if it developed some issues not that long after I got it.

[Bill Moore]

I have cleaned the connections in the Peavey jacks in the past, even going as far as disassembling, and retensioning the switching part. Any more, when I have to take one apart, I just change them all on the front panel. It's not that expensive, and will probably give no problems for years. CE/AES is a good source.
(Not just Peavey, but any modern amp with the plastic jacks!)

[Chilao]

Originally Posted by Chilao

Thanks guys, I much appreciate the diagnosis on this. I'll open her up after work this evening.
One more question, what is the trick to removing the grill cover on the Teal 112? The 65 is held in place with some heavy duty velcro. I don't see any screws and i'm afraid to yank or pry on it too hard.
Thanks again, don't know where i'd go with out this forum resource.

Cleaned out those jacks and everything is great. Just a little shot of my Wondermist and all is well. Thanks for the great advice!