after testing almost all caps I've reached the conclusion that for me, the entire OD line is not at all defined and really muddy in overdrive.
I've tested all caps with alligator clips in all positions and have reached the following conclusions.
(rated from best to worst, definition wise, definition = not muddy at all settings, treble is not harsh, but musical and bass is not boomy, but tight)
Coupling Caps:
1. Musatrds
2. Solen and MODs
3. Mallory
4. OD 6PS
5. OD 716p
6. OD 715p
Treble Cap:
1. Mustard (or mustard in series to produce picof values)
2. Ceramic (tested Murata)
4. Mallory
3. Silver mica (really harsh)
Mid cap:
1. Mustard
2. Solen
3. Mallory and 6PS
4. OD 715p
5. OD 716p
Bass cap:
1. Solen
2. 6Ps
3. 716p
PI caps: (not a big difference overall, mainly less ossicilations between these types of caps)
1. Solen
2. 6PS or 715P
the mustard caps i tested are all NOS, the solens are my new favorites after from what i've tested, i've done tons of back and forth testing (in the time frame of 6 hours).
what i've looked for is clarity and definition, the amp is a beast for recording now).
also, some more conclusions i've reached after testing:
1. the high plate setting REALLY compresses the amp compared to the classic tonestack.
2. the mepcos are nice resistors, but somewhat dull sounding for me, i've used 1watt vitrohm carbon comp resistors which turned out awesome in both high plate and low plate, sound is more "alive" if that makes sense.
3. 150k vs 100k or even 75k, the 150k is a kind of compromise I think, the 100k works best for dynamics, the 150k compresses everything somewhat, the difference is less than minimal between 100k and 150k, i'm leaving the tonestack slope at 100k (I like dynamics).
4. high plate vs low plate, as i've said before, I prefer dynamics, so i'm leaving it at low plate.
5. power amp section (PI and everything else) is REALLY important to the tone, i'd say it's 40% preamp and 60% poweramp, I changed all the 6PS caps to solen caps, sound is more alive by far than all the stock parts used.
6. All the caps i've used were marked by outer foil and placed accordingly, the caps i rated the best (mustards and Solen) stopped ossicilations almost entirely in all overdrive settings (I can set OD trimmer almost to max and i get no ossicilations).
I'm going to leave the circuit at low plate and do some more testing tomorrow by trying to test the circuit without a presence control and NFB only, see if that makes any difference.
I've also added two switches (One SPDT and one DPDT) to convert the tonestack to skyliner.
Clean side of things, Low plate is far more dynamic, sparkly than high plate and much less compressed, I like this because i'm really dynamic with my playing as i'm mainly treating the guitar as a musical instrument rather than a guitar producing solos and chords, so it's important for me to be able to hit the strings HARD and get the amp working HARD, which the high plate lacks compared to the low plate.
it's a bit funny, I actually went somewhat from a #102 high plate skyliner to a #124 low plate classic with 330pf snubbers on the Preamp tubes
