Build Your Own Clone Message Board

I have the rev 1 of an opti-comp. Sanchez recommended using an 18V pwr sup. It helped dramatically. The fluttering has pretty much gone away but the unit still "changes" the comp effect. The "intensity" of the effect is still intermittent. I feel the effect could be so much more. Again, I've completed assembling an armstrong twin(love it),a byoc reverb (it's overkill!) an Allen and Weber amp. They all work wonderfully. I've gone over the oc's circuit over 6 times with my DVM and everything seems to be in order. I added a release pot and put in a 1uf cap for a faster attack.

This frustration is rewarding as it is motivating me to learn more about electronics and circuit designs. At smallbearelectronics they describe the optocoupler,VTL5C4/2,as used in "modulation" type circuits, I believe a phaser. Is it possible that I have a defective optocoupler? Has anyone tried using a different optocoupler such as the VTL5C4 instead? Any insight,suggestions,help, or further
suggested reading would be greatly appreciated.I wish I had the words to accurately describe the oc's behavior, but I KNOW it isn't right, even though it is subtle.

I have probably 25 other comps so I'm not at a loss, but I'm a stubborn 50 year old SOB that is somewhat persistent. At my age, time really is at a premium. Thank you.

Sure, it is possible that you could have a defective optocoupler. You could always try a new one to see if that helps your problem.

I wonder if this is of this any help:
http://www.buildyourownclone.com/board/viewtopic.php?f=19&t=19809

To coolhand and gutarmageddon:
I ordered a few different optocouplers and will let you know the results. It'll be a few weeks before I have time though. Thank you for your input.

You can use the VTL5C2. It's a $1.50 cheaper than the VTL5C4/2 and $.50 cheaper than the VTL5C4.

http://www.smallbearelec.com/Detail.bok?no=346

You just need to make a minor modification when installing it on the PCB. You can either bend the lead on the right to go into the center eyelet on the PCB or do what I did. Which was to add a small jumper from the right eyelet to the center eyelet.

Your problem is not the optocoupler, but the 1uf capacitor you are using instead of the 33uf. That's the source -- I know because I've tried it, and the solution is to increase it to at least 4.7uf, probably more like 10uf.

If you're referring to my photo above the 1uf in the 33uf cap's spot is not a problem. It is part of the 3-way attack switch mod for the pedal. The two extra caps are a 33uf (left) and a 100uf (middle).

3rd post down...
viewtopic.php?f=19&t=17982

the release knob mod gives the pedal a ton more squish if thats what your after
viewtopic.php?f=19&t=17982

There is a problem with the 1uf attack mod in conjunction with the release control. I've tried it several times in different pedals, and I got a very choppy sustain whenever I set the release control less than the stock 4.7K resistor. If you set both the attack/release controls too fast, the compressor can produce a pumping/choppy sustain.

Hmmm. Has anybody else done this mod and had this problem?