Some issues with a L5 Preamp

[U4U]

Hi, just build a second one, but had some issues with this one. Channel switching works, but both channels produce ugliest distored flat sound! Soldering was done very clean, no visible short circuit...

Issues
1. Bypass works, but LED is always on
2. Limit LED is always on
3. Flat distored sound on both channels

ICs:
IC4 - IC9, IC12: RC4558P
IC1: LF356N
IC2, IC13: LM741CN
IC10-IC11: CA3080AE

Semiconductors as described and most of the parts were ordered from Mouser, but replaced some 10% Wima caps mentioned in the parts sheet with 5% Wima caps. The  distored sound seems to be an issue depending on the switchcraft jacks, which obviously do not work properly. They seem to offer some space and the plugs seem to be shaky this way which results in flat and distored sound.


Maybe someone runs into equal issues or has an idea what happens here. I have used a plain enclosure for the first build and a black enclosure sold by aion for this build.

Thanks a lot

U4U

[aion]

How are your power rails if you measure the "TEST" pads in the upper right? Are you getting the full +/-15V?

If the "Comp" toggle switch is turned off, does the LIMIT LED turn off as well, or is it always on regardless of the switch position?

I would also look at the CA3080 chips. If those are the only two you have, you might try swapping them around so that the one that was in the compressor is now in the distortion section and vice versa - and then see if anything changes. That'll help you isolate the problem at any rate.

[U4U]

Hi Kevin,

testing has more or less various results, all in a closer range around 15V, ~14.97 to 15.04V (positive pad) and -14.98.to ~ -15.04V (negative pad), varying in different tests.

Limit LED doesn't light off if comp switch turned off. It is always on - indipendend from toggle switch position.

Have exchanged both CA3080AE and put in the ones from the other pedal, which has an equal effect

Bypass LED is still always on too

Thank you,

U4U