Kapo_Polenton":14rru1wv said:
Modreveal time, sounds great. Were they evasive mods that had you cursing at your PCB board and having to disconnect a ton of leads to get at it?
What I did to the 2204:
1. Replaced the V1A cathode resistor (10k stock) with a 4.7k and bypassed it with a .1uF FILM RADIAL cap.
2. Replaced the V1B cathode resistor (2.7k stock) with a 820r and changed the stock .68uF to a .47uF bypass cap.
3. Bypassed the V2A cathode resistor(820r) with a .68uF cap.
4. Tone stack lift ( removed the ground wire from the 25K L middle pot.)
5. Replaced the 33k tone stack slope resistor with a 47k.
6. Replaced the 100k NFB resistor with a 47k.
7. Replaced the stock .1uF on the presence to a .68uF.
8. Lowered the stock filtering (50uf+50uf) to 32uf+32uf preamp (16uf+16uf screen/PI) I left the mains at 50uf+50uf.
The tone stack lift gives the amp more gain, the middle bass ect. controls will lose some FX but very easy to dial in this way.
The .68uF (SoZo) on the presence affects the mids & highs.
The .1uF (stock) only affects the highs.
The 47k NFB resistor makes the amp sound '67-'68 plexi.
It's a little tricky working on a PCB board.
The thing is you don't have to disconect all the wires from the PCB board.
Just prop it up with something so that you can get underneath the broad with the solder gun and try not to burn the wires.
Make sure you always discharge the amp before working it.
Cheer's Cody
