Metropoulos Forum

Hi, I built a JTM 50 with a few tweaks- .0022uF V1a coupler, .01uF V1b coupler, .68uF V2a k cap. dal voltage PT (450 and 400 B+) a switchable internal jumper on V1 to blend the channels (which is usually on) and a LarMar PPIMV. I run the bright channel on 10 and blend the normal in to taste.

Sounds great, but it gets a little too muffled and flubby on the low end when i have the normal vol up above 5. I want a little more gain an fatness in the mids an upper mids, while keeping the bass clear and tight. I was thinking by going with the small V1a coupling cap that i could blend it in an keep the bass tight, but its not quite there. Would adding a bright cap to the normal channel be effective or would the bleed off in the mixer section kill it?
could I go even smaller on the V1a coupler to effectively make the normal channel a midrange fatness control?

THANKS!

I find on this type of amp that turning the bass down to 2 and the presence up to 8 does the trick (with all the other controls on 8 except the unused channel on 4) I do not jumper with these amps they are fat enough without it (cf the split cathode amps which often do benefit from jumpering). That is without all the mods you describe. I use a 100pF bright cap if I need to turn the amp volume down as opposed to just the guitar knob
Speaker choice is important and these also sound best through a G12H 4x12 whereas a split cathdode amp suitably cranked will get there through a G12M quad in my experience but YMMV of course.

try like a 100pf bright cap over the normal volume. dont even solder it just clip it in and try a few.