Fender Super Reverb Mods

[jelle]

Yeah, should not be too hard..

I managed to stuff the Super Texan modification (two separate preamps with shared reverb and an effectsloop) into the same amp. That amp was crowded!

Guess which mod I preferred tonewise.....

Jelle

[Bob-I]

one more thing....the phase inverter, is it still fender? How about changing the 470 ohm resister into a 820 and stick a 12AX7 in it and maybe even add a presence circuit?

Just a thought,
Jelle

Good suggestion. I swapped out the 470 to an 820 and put in a 12AX7. It's pretty dramatic but very boomy so I swapped out the .1uF couplers with .022uF and it's sweet and smooth. I also swapped out the .001uF PI input with a .022uF.

Next I modded the dropping string. I was getting 240V on the V1/V2 plates. I increased the 4.7K to 15k and now I'm right at 204. I can't use the Dumble string because I only have room for 3 filters after the choke, screens, PI and preamp. The reverb is off the screens. I'm thinking of making another board, but that's against my goal of using the Fender boards.

I'll see if I can get clips later. It's really improving.

[jelle]

I do not know what your voltage is for the reverb mixer but I would try to get the reverb mixer stage at 200v as well. Maybe you can tuck a 20uF HV cap and a dropping resistor on the board somewhere....I'd tap the B+ for this stage from between the supply for the pi and the OD stages..

Also the reverb transformer could use an additional supply node to reduce hum. I did this in my amp and it worked out better than I hoped for. I hope this helps! I'm interested to hear your clips.
Jelle

[Bob-I]

I tweaked the PI and PS dropping string. What'cha think?

http://www.patmedia.net/bob-ingram/DClone/Clip2.mp3

Just for the hell of it, a MIM Strat

http://www.patmedia.net/bob-ingram/DClone/Clip3SC.mp3

[heisthl]

If you're looking for grail tone my bext guess is the OD plates are too high, what are the voltages on od1 and od2?

[fabiomayo]

Nice tone. I think it's improved from the other clip, more bloom and dynamics.
More aggressive too... Somewhat more 'Marshally' rather than 'Dumbly'
to my ears.

Keep it up!

[Bob-I]

If you're looking for grail tone my bext guess is the OD plates are too high, what are the voltages on od1 and od2?

204 on each. IME that's about optimum but I can try lowering more.

[heisthl]

I would think 204 plates on the OD tube is good - I was thinking the stage sounded more like a distortion rather than an overdrive which I've heard with too much rail voltage. AT 204 the only way rail voltage is too high is if they are biased on too hard. Is the amp capable of "clean" overdrive?

[Bob-I]

I would think 204 plates on the OD tube is good - I was thinking the stage sounded more like a distortion rather than an overdrive which I've heard with too much rail voltage. AT 204 the only way rail voltage is too high is if they are biased on too hard. Is the amp capable of "clean" overdrive?

They might be biased a tad hard. I'm measuring 1.4V at the cathode, I think it should be more like 1.8. I'm leaving standard Fender values in there, I may have to change them for a more Dumble-esk tone.