Would that be a good place to add a LED to add a crunchier tone to the distortion?

Thanks for the clarification, yes I did google the op amp gain blocks but 99% of what I found kept going through mathmatic equasions and I just don`t have the education of electronics theory to really understand what they are even talking about,,lol. Yes dumbing it down will be greatly appreciated,,lol.

So basically to get more gain I would need a higher ohm pot and lower the value of R8 ? That way I keep the frequency response of C4 in the gain stage even?

Hope this comes out ok,, I really appreciate your help JM ! !

I found out that my volume pot has issues, and the noise was getting worse and the distortion started sounding like it was compressed badly, changed out the volume pot to a new CTS and it cleared it up alot, plus I found that the 1/4 jack plug on the cable going from the amp to the cab was crackling when I wiggled it, replaced it with a new heavy duty audio cable ( the old 1 was a elcheapo) and she is much much better. I wouldn`t have thought the cable would make the difference it did but that brought the biggest change in the sound, it doesn`t sound like the amp is forcing the sound through the cab anymore.

Thanks for the info, where are the feedback resistors usually located? Are they in the chain with the op amp ?

I just picked up a old Duece VT series to use as a guinnea pig for some mods. It has TL072 op amps in it, what would be a good op amp to replace them with to get a higher gain sound ?

Here she is, I got her where I want her now.
http://www.youtube.com/watch?v=7WXwWwl6-Qw

Thanks for the replies guys, Tony thats what got me wondering  was browsing ebay and finding several different 12ax7 add on boards, found 1 with 3 12ax7`s for the same price as the one you shown. May give my local tech a call and see what his thoughts are, he builds Hiwatt clones and sell out of his store and know 2 guys that bought them and had zero trouble to date out of them. So he must know what he`s doing.

How hard would it be to put a single 12ax7 preamp in place of a solid state pre amp?

Thanx.
I would like to add white descriptions for pots, but I haven't figured out a way to do it yet
[/quote]

Vinyl graphics might work ?  Put them on after you paint then spray a flat clear coat on top to protect.

Sounds like screen grid resistors are shot, the big cement looking resistors on top of the tubes. If you have a multimeter I would check the ohmage on the 2 spots compared to the other 2.

Thanks Jack, I got the tone pot replaced and that lends much more to the variety of tones possible. I have been comparing several different amp schematics with my mace schematic and found a few things that I thought may lend to the elder Peavey mud tone. There is a resistor in the mace that is a 10K it goes between the bass pot and the treble pot, I noticed on a few marshall models they have 100K resistors. Makes me wonder if switching the 10K to maybe a 50K  would also help with the mud tone and give the bass and treble more independant tonal characters.

That be it Teemuk,, pretty cool little amp, the different tones you can get just with the eq alone is pretty sweet. And I like the contour knob so you can make it fat and loose or tight as bark on a tree.

I can`t find a schematic or anything on the amp, I may try and google Rogue amps and see what I come up with. O had played other 12ax7 amps before like the Peavey Classic 50 and it just doesn`t have the crunchy sound like this one has. The amp also has a guitar tuner with LED`s built into the head, flip a switch tune and keep right on playing. It has a solid state power amp and the tube is evidentally buried inside the chassis as it isn`t visable from the outside. Will post up a short video video so you can see and hear it, I couldn`t believe how good it sounded and wasn`t in the market for another amp but the local guy made me a sweet deal and I walked out with it.