Custom High Gain Mod in a '76 JMP 2203

[EddyLenz]

Hi Everyone,

I just finished modding this amp with a custom 4 stage non-cf high gain mod. It's based on the gain channel of my 2 channel prototype, but I've tweaked it for a long time. It also has a tube fx loop.

There's a bass shift switch on the bass pot, a mid voicing switch on the gain pot, and a gain structure switch, that takes away some saturation.

It can do crunchy 70s, 80s Hard Rock/Metal, and more modern Metal sounds.

Let me know what you think!

 

[Racerxrated]

Sounds great Eddy! Another winner.

 

[EddyLenz]

Sounds great Eddy! Another winner.

Thanks, mate!

 

[imzadimark]

Great tonez and playing!

 

[EddyLenz]

Great tonez and playing!

Thanks!

 

[PBGas]

That sound amazing! Well done!

 

[harddriver]

Wow, big gain, yet is not overly compressed, tight on the lowend and still retains the Marshall crunch and clarity on the fretted root notes yet is quite open sounding. You've balanced alot attributes that can go really wrong when building a high gain circuit Eddy, Great Job there.

Yeah Eddy.... I would say this is your best yet as well as your two channel you posted not long ago.

 

[EddyLenz]

That sound amazing! Well done!

Wow, big gain, yet is not overly compressed, tight on the lowend and still retains the Marshall crunch and clarity on the fretted root notes yet is quite open sounding. You've balanced alot attributes that can go really wrong when building a high gain circuit Eddy, Great Job there.

Yeah Eddy.... I would say this is your best yet as well as your two channel you posted not long ago.

Thanks, guys!

It took lots of hours to get it right and after I changed the 6550 back to EL34, I started to get close to what I wanted. The 6550 somehow always gave me that Slash tone/feel, that I didn't want with that amp. I also noticed that the Tung-Sol 12AX7 didn't go well with that circuit. They were too bright and had something weird in the upper mids. I've now got two old tubes from the 70s/80s in it, and it's much better. They are between the Tung-Sol and JJs, which are the smoothest that I've tried.

 

[aside]

Sounding real good, and some very tidy playing as well

 

[EddyLenz]

Sounding real good, and some very tidy playing as well

Thank you!