DS-1 Keely Mod

Started by PedalSouldier, August 10, 2016, 08:23:07 AM

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GibsonGM

That is a great place to look, Luke.  :)  I should have noticed that too.   

Look for where your 'flat spot' is on the LED, which is the cathode (band, in the schematic)...and see if it is 'pointing' the right way.
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anotherjim

Good point about LED direction. Some material tells you to judge polarity by the different lead lengths, which is no help if they've been cut down. There is a flat side on the base of the LED body by the cathode and this corresponds to the printed ring around the body of the diode it replaces.
Diode or LED clippers, the op-amp driving them will clip first with gain set high - that's the primary distortion until the guitar fades low enough and the clippers carry on providing distortion until the fade falls under their clipping threshold - after which it's fairly clean.

PedalSouldier

I will Check them ASAP and let everybody Know if that was the culprit.

I'm learning..

duck_arse

Quote from: anotherjim on August 15, 2016, 07:25:22 AM
Good point about LED direction. Some material tells you to judge polarity by the different lead lengths, which is no help if they've been cut down. There is a flat side on the base of the LED body by the cathode and this corresponds to the printed ring around the body of the diode it replaces.

I look into the led body, side on. the kathode sits in a big-headed lead, which I call the anvil. it also has the little cup/divot/reflector on top the anvil, where the die sits and emits.
don't make me draw another line.

Cozybuilder

I just use my diode tester to orient an LED if the legs are nipped- especially useful when you've rolled your own Vactrol and used black heat shrink.
Some people drink from the fountain of knowledge, others just gargle.

PedalSouldier

I did a little bit of tweaking with the mod and found that two germanium/one germanium and LED (separated by switch) was the sound I was looking for.

Only problem is that I'm having an almost Morse code sounding beep when I turn the pedal on. I suspect grounding issues.

Other than that the pedal sounds good.
I'm learning..

lukeferg

Good to hear you got it working!
By using one germ and one LED you're getting asymmetrical clipping, supposed to be more tube like.

Check biasing of transistors if it's going morse codey. One might be turning on and off causing it to stutter.

lukeferg

Sorry, wrote my last reply in a hurry and didn't read your post properly.
I have no idea how you would be getting a beeping morse code sound, that's weird.

anotherjim

Get the morse transcribed. It probably says "Help! I'm a prisoner in a Boss factory"  :icon_eek:

PedalSouldier

Haha. I found that the sound was just in the air and not being caused by the pedal but the pedal still keeps amplifying it. This pedal has been a pain in the ass. but I suspect grounding issues.

I'm learning..