OKAY! Built!!! Works and sounds AWESOME! However - J175 jfets are DGS, not DSG. I went ahead and did the layout as you drew it, and tried out just about every jfet I have with that pinout. The octave down is apparently GREATLY affected by that bit, so the one I settled on was a BF245C. I twisted the legs on a J175 to see if it would work, and it did, however, the octave would cut out whenever I would dig into the strings. Also - TL062s work fine but tracking is WAY better with TL072s. Like almost digital/POG tracking perfect. Way better than I would expect from a 4013. This is an awesome circuit and is going on my board as soon as I box it up!
I test my builds with a baritone guitar tuned to B Standard. Also I must mention, sockets on all the ICs are worth it. Had to try a couple flip flop chips and dual op amps (settled on a mix of 4558s and TL072s) too. This effect is unity gain but tracks better than any analog circuit I've built so far.
I built it and it works but somewhat weak...tried the suggestions Chris made above and it is better but not powerful enough. And, there is no difference when I remove IC4... still sounds the same, could that be a hint to the weakness?
I had no J175s!!! However, they just showed up yesterday so...
ReplyDeleteBuilding this one up now. Haven't fired it up yet. But you should update the layout to say "51 cuts, 31 links"
ReplyDeleteOKAY! Built!!! Works and sounds AWESOME! However - J175 jfets are DGS, not DSG. I went ahead and did the layout as you drew it, and tried out just about every jfet I have with that pinout. The octave down is apparently GREATLY affected by that bit, so the one I settled on was a BF245C. I twisted the legs on a J175 to see if it would work, and it did, however, the octave would cut out whenever I would dig into the strings. Also - TL062s work fine but tracking is WAY better with TL072s. Like almost digital/POG tracking perfect. Way better than I would expect from a 4013. This is an awesome circuit and is going on my board as soon as I box it up!
ReplyDeleteChris! You are awesome, great job and many thanks!
DeleteThe J FET pinout is now corrected (easy fix!) and it is TAGGED.
Did you use it with guitar or bass?
DeleteI built the Multiplexer Octave some years ago, but I never made it works properly (volume and hiss issues).
I test my builds with a baritone guitar tuned to B Standard. Also I must mention, sockets on all the ICs are worth it. Had to try a couple flip flop chips and dual op amps (settled on a mix of 4558s and TL072s) too. This effect is unity gain but tracks better than any analog circuit I've built so far.
ReplyDeleteShouldnt Q1 be DGS for a J175
ReplyDeleteI built it and it works but somewhat weak...tried the suggestions Chris made above and it is better but not powerful enough. And, there is no difference when I remove IC4... still sounds the same, could that be a hint to the weakness?
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