Peavey Bandit 65 mods, anyone have any good mods?

[iep]

Hi, just found this thread and thought I'd share a few thoughts.

I've just bought a used Bandit 65 (not even had it delivered yet) and have set to work planning mods. I like the Peavey clean tone so don't plan to do much there but agree with many that the distortion leaves a lot to be desired. Even in when it was first designed it sounded crappy among its peers.

I've taken a look at the schematic for the amp that was provided in this thread:

http://music-electronics-forum.com/t16210/

and sketched out the gain/distortion stage in a simulation tool:



Ignoring the diodes I have circled in red. This is pretty much as per the schematic with the saturation knob set to its minimum and the Lead Pre knob set to its max (so max distortion achievable with minimum saturation). I used this schematic to run a simulation of the circuit with a 1kHz sine wave input signal.

The waveforms below give the actual output signal and an FFT showing the frequency content including harmonics out to 20kHz:



Looking at the signal this is an attempt to mimic overdrive rather than distortion where no signal clipping occurs but instead we see slew rate distortion. Essentially, gain is applied to small signals but not larger signal. It's a form of compression really. Seems quite neat until you check the FFT on the left. Basically, we are still seeing distortion totally dominated by odd order harmonics (3, 5, 7 etc). So, pretty noisy, not very musical and certainly nothing like the even order harmonics that you get from a nice Valve amp in break up.

Spin the saturation knob to the max and things get 'worse':



I say 'worse' because this is now just a classic distortion signal. Hard clipped top and bottom and totally dominated by the odd order harmonics again. This is actually okay if you are looking for a true distortion tone (it's more or less what the Boss Ds1 does). But it's a bit disappointing since, sonically, it's not really much different to to the tone with the saturation knob at its minimum.

Are there any easy mods to fix this? probably yes. I should add that I hae not been able to try them out yet but below is my own plan for my used Bandit 65:

Mods to the schematic:



All I have done here is to add two additional diodes to the feedback section (at the top) and one to the hard clipping section (at the bottom). The aim is to produce asymmetrical clipping which accentuates the even order (more musical harmonics).

What does it do?

Overdrive (saturation at minimum):



As you can see, the waveform is now asymmetrical about 0V and the result is that the dominant harmonics are now the 2nd and 4th, which are a lot easier on the ear. The dominance of these even order, lower frequency harmonics 'should' also lessen the buzzy wasps in a jar tone of the amp.

Distortion (saturation at maximum):



Again, asymmetrical waveform about 0V and greater even order harmonics. That said, it's meant to be a saturated tone so hard clipping is important so I have only added the one extra diode in order to maintain the 3rd and 5th order harmonics dominance.

The diodes I have messed with are CR3 (three in place of one) and CR5 (two in place of one). You can just use the same 4148 diodes already in the design.

Want to go further? Replace each silicon diode (CR3, 4, 5, 6) with a pair of germanium ones (like OA90s). Of course, to maintain the mods described above CR3 would be replaced with 6 series germanium diodes and CR5 with 4 series germanium diodes. Germanium diodes can/do make a difference in clipping circuits. I have used them to good effect n the hard clipping stage of my Boss DS1.

Anyway, possibly a bit premature given that I have not completed the work yet but thought I would share.

Cheers,

iep

[Slobrain]

You are absolutely correct. I must hide my face behind this Help sign and say 100 Hail Mary's.

Tube amps are great in the studio or a small bar where you can really hear the finer qualities. If everybody is playing loud people aren't going to notice the subtleties. If you are able to crank the tube amp loud enough for power tube distortion and that magical interaction between OT and output tubes and speaker, go for it!

SS amps are easier to lug around and less likely to be stolen. And if they do get stolen you should be able to find something comparable for not too many bucks. And no need to worry about finding the perfect tubes for it.

On the downside, most of the OD channels on SS amps are pretty lame- but you could say the same about a lot of the tube amps from Fender and Peavey! I only buy SS amps that have a nice sounding clean channel and use a pedal if I want some dirt.

Steve

P.S. Line 6 amps used to sound terrible if you were more than a few yards from the stage. What sounded so cool when you were right next to the amp would dissipate into mud as you got further away from it. "Whaddaya mean you didn't like the way my guitar sounded? I thought it sounded great!"

I once opened up a small line 6 amp and the guts looked like a computer motherboard. I couldn't fix the issue... Steve I see you still have the Blue Guitar site up.. Good for you

Too bad T-boy wont go back to the old Ampage format... I used to have a blast on the Ampage site in the late 90s, so many cool folks to talk shop with...

[Chuck H]

Line 6 amps used to sound terrible if you were more than a few yards from the stage.

Which was an upgrade to how they sounded up close! Now, with improvements they sound terrible from anywhere in the room

[Steve A.]

Hey Steve, Did you mean a Peavey Special 130? I never seen a bandit 130 before...

You are absolutely correct. I must hide my face behind this Help sign and say 100 Hail Mary's.

Tube amps are great in the studio or a small bar where you can really hear the finer qualities. If everybody is playing loud people aren't going to notice the subtleties. If you are able to crank the tube amp loud enough for power tube distortion and that magical interaction between OT and output tubes and speaker, go for it!

SS amps are easier to lug around and less likely to be stolen. And if they do get stolen you should be able to find something comparable for not too many bucks. And no need to worry about finding the perfect tubes for it.

On the downside, most of the OD channels on SS amps are pretty lame- but you could say the same about a lot of the tube amps from Fender and Peavey! I only buy SS amps that have a nice sounding clean channel and use a pedal if I want some dirt.

Steve

P.S. Line 6 amps used to sound terrible if you were more than a few yards from the stage. What sounded so cool when you were right next to the amp would dissipate into mud as you got further away from it. "Whaddaya mean you didn't like the way my guitar sounded? I thought it sounded great!"

[Slobrain]

Hey Steve,

Did you mean a Peavey Special 130? I never seen a bandit 130 before... right now I have an 1982 Special that's 120 watts, then I got the Bandit 65 which is cool when I run my Boss ME50 thru it. I like Peavey amps even though I have a few Fender tube amps and a Marshall 1987X full stack to boot. I guess I sort of have G.A.S....lol I have owned too many SS and tube amps over many years, they were all good.

Imho I think any amp can serve a purpose, heck it depends on what you can get out of it. After all Dime played on Cowboys from Hell with a Randall SS amp.

I can bet that many folks used SS amps in recordings we hear on the radio. Didn't John Fogerty use a Kustom SS in some of his recordings? Brain May used a SS amp for some stuff too.

I cant afford to be a snob to the SS realm when I used SS amps in clubs for years before affording a really good tube amp.

In the very early time of my guitar and band playing I used Peavey SS amps at many party's and no one ever said, darn that was some sorry arsed guitar tone you got... It was a 1980 Peavey (the century) with a home made 2x12 cab using eminence generic 12s.

besides I seen Brent mason playing a Peavey special and getting really cool tele tones from in it. Lots of Nashville guys like the Peavey amps.

my first 4 amps when I started to play in Oct 1979, Univox U65RN for learning, then a Fender Tremolux 40 watt tube head with a 2x10 Fender cab, (Sunn Beta series 2x12 Horrible amp), and then the Peavey The Century 100 watt head with home made 2x12 cab. Then in 1982 I got a Peavey Bandit till 1984, in 85 I got my Peavey Renown amp. That was a good club workhorse. Its still out there somewhere being used...in 1986 I got a Marshall model 1987 50 watt non master head that was made in 72 or 73 with a Marshall late 60s 4x12 loaded with 30 watt celestion greenback if I remember correctly I paid the guy $250 for the rig but had to put a new power transformer in it and new tubes too. Awesome amp.

[Chuck H]

Um, PV bandit is somewhat reliable...but not as reliable as a Fender.
It certainly does not achieve the most reliable...

Well I think a Chevy isn't as reliable as a Ford! Oh, wait a minute... That statement was completely erroneous because I didn't specify what years/models I'm talking about?

Your statement is too broad. Please, tell me what Fender amps are more reliable than the Peavey Bandit 65.?. Age not withstanding. Also, please tell me what qualifies your choice. Both regarding any lack of reliability for the Bandit 65 and whatever graces your choice possess. Remember, My choice is the Peavey Bandit 65 from the early 80's. I honestly wonder what's more reliable.

[nashvillebill]

I guess we need to make sure the word gets out: those old Peavey amps are worthless and unreliable. Nobody should buy them. Spread the word, they aren't worth a dime. They're heavy and those pointy Peavey logos are ugly. Yep if you've got one to sell they aren't worth much.

..............(gotta keep those prices low so we can keep snagging those Peaveys cheap)

[Steve A.]

Hey, I put a Bandit 130 on layaway at Guitar Center last year (it was $75.) I did pass on it because I really am running out of room for more amps.

I used its baby brother- a 20 watt Studio Pro with a 12" Black Widow- when I was playing in the music ministry in the late 70's/early 80's. My 65 Pro Reverb was too loud and too temperamental; when I played it loud and hard and fast it would make a sound almost like water sloshing around... "in-di-gesssttt-ion" from those antacid commercials. Once I replaced the big filter caps it stopped doing that- but then again it might have had something to do with me setting the bias control to 11 since that gave me the loudest sound and best tone.

I just found one of those Pepto-Bismol commercials from 1977...

Steve

P.S. I was planning on lowering the gain and smoothing out the signal in the OD channel in the Bandit as I have been doing with the 1990's design Fender SS amps to make them something I enjoy playing. (Usually the clean channel doesn't need much tweaking at all.)

[soundguruman]

The Peavey Bandit65 might be the most reliable amp ever made!!! The clean sound is entirely useful and there are even some overdrive sounds that are useful. Up to modern standards? No way! But if you can use a Dbox for your clipping that amp will do you right for a long, long time. Basically... Don't ask it to be what it's not. It'll make a good clean tone and do it reliably. Add a distortion box and you've got a real club slave.

Take this with a grain of salt. I cut my teeth on a Bandit65

Um, PV bandit is somewhat reliable...but not as reliable as a Fender.
It certainly does not achieve the most reliable...

[Slobrain]

The Peavey Bandit65 might be the most reliable amp ever made!!! The clean sound is entirely useful and there are even some overdrive sounds that are useful. Up to modern standards? No way! But if you can use a Dbox for your clipping that amp will do you right for a long, long time. Basically... Don't ask it to be what it's not. It'll make a good clean tone and do it reliably. Add a distortion box and you've got a real club slave.

Take this with a grain of salt. I cut my teeth on a Bandit65

Hey Chuck,

I finally got to crank the Bandit up using my Boss ME50, I set up the gain channel clean and ran the Boss me50 thru that. Man that little amp actually sounds good for being a SS, big lows and LOUD....

I guess these are definitely sleeper amps until more folks start to catch on and cause the EBay prices to go up... Maybe I should buy up all the under $100.00 Bandits and then stash until that happens...lol...

Cheers

[Slobrain]

Reading on the net about the bandit amps I found there is actually a long thread on this particular amp on another site and a cult following too... Go figure, I think the Bandit 65 is considered a poor mans deluxe reverb in Nashville. Those guys like them for that country sound using a tele. I had one but never liked it in the early 80s but then again I got rid of it and never looked back. in the early 90s I picked up the 80 watt version with the teal stripe and used that for practice for a small while. It was pretty good.

Regarding the older one with the scorpion speaker you actually have to push that speaker to get a better sound out of it but it is mid sounding, actually not a bad thing when trying to cut thru a band mix. Much better too than the scooped sound of the death metal players. Its funny but I see these on eBay all the time for cheap.

I guess Hartley cant complain too much since he does build some affordable gear and look what he has done with his company that started in an old attic and now a multi billion dollar company...

[soundguruman]

Well.... As my dad used to say, "You can't make a silk purse out of a sow's ear", lol. But... if you are on a budget, try some pedals. It won't be a boutique amp no matter what you do. But if you are just jamming or playing clubs, you can make it usable. Crowds are much more forgiving than musicians. Or as SGM says. Sell it and get something you like. For cheap SS amps, I've been impressed with the modern Fender Frontman series lately. Not my favorite amp by any means, but I picked up 212R for $35 the other day. It's usable. 100 watts. Two 12 inch speakers. Spring reverb. As the saying goes. It doesn't suck.

As far as solid state amps are concerned...
Fender is surprisingly good sounding.
And they seem to last just about forever.

I was giving stage 100 a double take, because it sounded so good.

Course, it don't sound as good as tube amp, but on a low budget, you could probably be challenged to find a better one.
sounds much better than PV...and has a much better quality speaker.

And both Fender and PV have good parts support.

Line six is choice of Heavy Metal Monk.
And also sounds quite good, if you like the digital modeling sound.
But others say digital sounds sterile.
And, if it breaks, it's disposable.

I kinda like a Cyber Deluxe, as far as Digital goes for me.
Surprisingly versatile...
and this is the amp that the Chinese copied, to make a line six...

[nashvillebill]

I really did not experiment with various op-amps: the amp (Classic VTX) had a bad op-amp or two when I got it, so I popped in the 5532's to replace the bad ones. I chose them because I had them on hand. I also had the OPA 2134's on hand (left over from a phono preamp build) so I said "hey what the heck, let's pop a couple of them in the first two spots" then buttoned 'er up and moved on with other projects.

As far as reducing the buzzing-bees distortion: Perhaps the other op-amps helped--or perhaps it's because my expectations have changed, and I'm no longer after the ultra-high-gain sound, so I'm dialing back the Saturation to get more of a "slightly overdriven" blues/classic rock sound, rather than an all-out cranked distortion. Speaker changes have helped too. While the Scorpions aren't bad, in their own way, I'm going more for a smoother sound and I've had good luck with the Lil Texas neos.

Have you posted on the ssguitar.com forum? Those guys have some interesting ideas, I don't hang out there much though.

[Chuck H]

The Peavey Bandit65 might be the most reliable amp ever made!!! The clean sound is entirely useful and there are even some overdrive sounds that are useful. Up to modern standards? No way! But if you can use a Dbox for your clipping that amp will do you right for a long, long time. Basically... Don't ask it to be what it's not. It'll make a good clean tone and do it reliably. Add a distortion box and you've got a real club slave.

Take this with a grain of salt. I cut my teeth on a Bandit65

[Slobrain]

Well, certainly the Peavey Bandit isn't quite in the same class as an original Fender Deluxe 5E3. Nevertheless, it's a dependable workhorse which takes pedals fairly well, and some folks seem to have rediscovered its usefulness. I think it got a bad rap for several reasons: 1) it's SS which has an auto-reflex action for too many people (ugg! SS!!) and 2) its a Peavey which gear snobs love to hate and 3) its distortion was the typical 1980's "bees buzzing in a box" sound when the Saturation was cranked way up (which was where we ALL turned it to!) IMHO this bad rap is unjustified.

If all it needs is a couple of op-amps, and maybe a cap job, I say go for it. The schematic is in this thread: http://music-electronics-forum.com/t16210/
A few bucks, and a couple of hours, to replace all the electrolytics would get it back up to a dependable level.



As far as modifications, a better speaker may help, sometimes the Scorpions had a midrange honk to them. A good Eminence would be less than $100. One possible circuit component change may help: I've read the steel guitar guys say that in the first couple of gain stages in Peavey preamps, changing the 4558 opamp to a OPA2134 helps smooth it out a lot. Ordinarily I would not buy into the "opamp rolling" philosophy, but here there might be some logic, since the OPA2134 is a JFET and the 4558 was a BJT. I think U1 and U2 would be the two likely spots for improvements. (in my Peavey Classic VTX, it had a couple of bad opamps: I replaced them with NE5532 but while I was in there I did stick a couple of OPA2134's in its U1 and U2 locations, and it works fine) The Saturation is pretty smooth but I don't crank it all the way up these days, just getting a little dirt in there is usually all I seek. So for a couple of bucks, that would be a low-cost mod to try. Otherwise I'd just use NE5532's.

Hey Nashvillebill,

So did the OPA2134 make the distortion better than the bees in a can sound these are known for? or did you like the NE5532s better? By far this little amp doesn't come close to a good tube amp but I remember using a Bandit back around 82 to 84 in the clubs, sold it and got a Peavey Renown 2x12 which has the autotransformer to get the SS closer to a tube amp sound. That renown was a heck of a good workhorse, ran that thru a Marshall 4x12 with the 65 watt speakers which made the renown sound even better too.

I just couldn't pass up a 50 dollar amp...lol.. Besides fixing it was fun too. Brings back memories of when I was in my 20s...