Distorted output and no Reverb

TomWhitwell / Spring-Reverb-Mk-2

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Distorted output and no Reverb #6

Closed danfastlikeflan closed 6 years ago

danfastlikeflan commented 6 years ago

Hi Tom, Hopefully you can provide some insight. I have already reflowed all joints and checked for solder bridges. Here are some symptoms:

-Module turns on and behaves the same with the jumper in either position and without the jumper on at all -The led is max brightness with all knobs full clockwise and then gets very dim when the cv knob is about 10% and then will get progressively brighter when rotating the main knob

with the feedback switch off, the output is very quiet and get louder until feedback is turned up to about 10% and turns into distortion any farther than that
The three feedback switches do provide three different tones
the wet output is always completely quiet
tilt has no noticeable effect

Any help is appreciated. Thanks, Daniel

TomWhitwell commented 6 years ago

That's quite a baffling selection of symptoms. The main LED sounds correct You can check the crossfade independent of the spring reverb by patching another signal into x-fade and checking that crossfade is smooth. Tilt acts on the send to reverb, so should only be audible in reverb tails Distortion - have you calibrated the module - setting the trimmer so that it doesn't distort

Are you using Brick or Spring?

Jumper = no impact = that suggests a short or missing connection somewhere - perhaps upload high res pictures of the front and back of the boards.

danfastlikeflan commented 6 years ago

Thanks for the quick reply. Here's a link to some pics: https://imgur.com/a/YYnqVJq. I have tried both the spring and the brick but neither resulted in any reverb. Even plucking the tank does produce any sound. I tried testing just the crossfade but its still very distorted there is nothing audible until feedback is turned up a little, even with the feedback switch in the off position. The trim pot does not have any effect on the sound. After playing a little more with it, it seems like inverted feedback and no feedback sound the same.

TomWhitwell commented 6 years ago

OK, so global problems like that might be... An IC that is the wrong way around - perhaps a TL072 on the front (panel) board? An IC that is not properly seated - so one leg isn't making a connection A power issue; a missing/reversed diode. You can see the schematic here: http://musicthing.co.uk/collateral/SpringReverbMk2-Schematic.pdf

danfastlikeflan commented 6 years ago

One of the diodes was backwards. Thanks so much for the help!