I recently acquired a Bandit 75 on eBay. I've noticed that the passive tone controls (T,M,B), while very effective in clean mode, seem to have no effect whatsoever in lead mode. The presence control is very effective in both modes. I've pulled the circuit board from the chassis to do basic cleaning, and while in there I saw no evidence of any modifications to the circuit. However, it doesn't make sense for Peavey to have designed in a tone stack bypass for the lead mode.
Does anyone have access to a pdf of this schematic?
On the lead channel if you have the "pull thick" engaged the tone controls are pretty well bypassed. Push the mid-tone control in and you should have full control. This is only applies to the lead channel. It has no effect on the clean channel.
See the Peavey website under archived manuals for a full description. The Peavey Amp Forum will post a wiring diagram if you ask.
My version doesn't have the "pull thick", or any pull function. It has button for "bright" on the clean side, and a button for channel switching.
Customer service at Peavey sent me the pdf. Believe it or not, the tone stack is BYPASSED when the amp is in lead mode. That is so weird! I've never seen a design like it. The only tone control available to the lead channel is the Presence control.
Hi JV,
I just simulated some of the Bandits circuit for a friend and the results where as sad as the tone/sound they produce.
You only get about 6/10 Db of boost/cut anywhere in the preamp circuit. ??? hum? No wonder my friend is not happy with his Bandit.
There are obviously many models of this rig but I get the impression they are all much the same.
You need at least 20 Db of cut at around 300/500Hz to get a worthwhile tone that resembles a guitar tone.
I built a very simple "Stand Alone Tone Stack" which improves the Amp dramatically, if your into building your own gear I can post it up here. [battery powered if you so wish]
I tend to try and work "Outside" of Amp circuits as much as possible as modding some of these circuits can end you up in more trouble than the Amp is worth.
Cheers Phil.
Thanks for the help, but I have to disagree about the -20dB cut in the 300-500Hz range. That's more opinion than actual fact. As clean sounds go, I really like this Bandit. However, I'm coming from the perspective of a jazz/fusion style. Most jazz players prefer a sound that is closer to flat than rock, country or funk players like. In fact, I prefer the response of the Peavey tone stack to most Fender circuits. Peaveys seem more responsive.
I'm not likely to ever design or build my own amp. I already have a full-time job, a wife and two bands. I'm also not likely to radically mod this amp, because for my purposes it isn't necessary, and because it's not a platform that's worth tinkering with. I appreciate your input, though.