After cap update there's a loss of attack/sensitivity

[pbman1953]

Back to the  Fender Super Twin for a sec. Even though I'm done with these the amps they had more attack/sensitivity before changing anything. Cap changes were made because it was humming badly and the new caps solved that. The cap kit I bought were very close values to the schematic. With conversation in the forum here's the changes that were suggested:


1- V1A- pin 6-100k resistor to a 68k
2- V1B -pin 3 -1500 resistor to a 680 ohm
3- V4B pin 1 from a 220k resistor to a 180k




Other real changes- new OT's so I could have outputs for 4 & 8 ohm. The first amp has a Mercury Magnetics OT and the second one has Heyboer. If you feel the OT's are the reason for the difference , enough said, otherwise I'm wondering if the preapp should go back to stock values.


I have 2 versions of this amp so I'll send both schematics . One is an older version and one is a version in between a non-reverb and a reverb version. Both are non-reverb

[tubenit]

An output transformer change can make a significant difference tonally.  Usually an improvement in my experience but not always. I upgraded a Dano Centurian 275 with a Deluxe Reverb OT .......... and after about an hr of playing, I put the original back in.


Of what you mentioned ............ I would guess the OT change and the cathode pin 3 resistor change would be the more dramatic differences.


with respect, Tubenit

[pbman1953]

Thanks I'll start with the easy stuff first the pin 3