My Cupcake trimpot is acting weird, not sure if this is normal... It is either loud and distorted or if it is adjusted so there is no distortion, there is a tremolo like effect to the tone. That may be there when it is loud, too, but is covered up by the distortion. It seems like a lot of the low range of the trimpot has no effect at all, it gets too loud and distorts very quick.
IC voltages:
1 4.79
2 4.83
3 3.98
4 0.01
5 0.02
6 8.16
7 8.17
8 8.80
Also, I used a matched pair of 2N5457, if that makes any difference.
I did not have a 4M7 resistor, but substitued a 3M9 + 750K resistor.
I did not have a 2K4 resistor, but substituted a 1k5 + 1k resistor.
Anyone have any thoughts on how a compressor may sound like an overdrive with tremolo?
what are the voltages on the FETs?
Probe the cathode of D1 while playing something and tell me if you get a DC reading.
Sorry, should have done that already.
Q1: D 0.01, S 1.45, G 1.30
Q2: D 1.45, S 2.42, G 8.78
With the trimpot at full, on D1 cathode I measure about 0.40 if I bang on it.
Quote from: AntKnee on December 07, 2014, 05:02:44 PM
Sorry, should have done that already.
Q1: D 0.01, S 1.45, G 1.30
Q2: D 1.45, S 2.42, G 8.78
With the trimpot at full, on D1 cathode I measure about 0.40 if I bang on it.
Check your pinouts. You shouldn't have 0V on any of the drains.
Quote from: midwayfair on December 07, 2014, 07:28:55 PM
Check your pinouts. You shouldn't have 0V on any of the drains.
Rechecked them all, have new numbers:
Q1 G=0.30 S=3.68 D=2.26
Q2 G=3.68 S= 4.66 D=8.78
Should I try changing out my 2n5457's?
Quote from: AntKnee on December 10, 2014, 02:05:19 PM
Should I try changing out my 2n5457's?
IMO Q1 have too low voltage you should try anther fet in there
Tried swapping out the fets, but no change.
The pedal is either clean with "vibrato" or distorted without vibrato. This is the only way I can decribe the sound. It is wavy, or tremolo like. Maybe its a phase thing?
Post clear pictures of both sides of the PCB.
The tremolo sound is probably ripple, from the envelope not holding charge properly. It's normal to have a small amount of ripple on the very tail end of a long note in a compressor with a short decay like this, but not like you're describing.