Author Topic: BOSS CE1 PROJECT: MN3002 or TDA1022P: DOC UPLOADED  (Read 29629 times)

skeeter

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Re: BOSS CE1 PROJECT: MN3002 or TDA1022P: DOC UPLOADED
« Reply #165 on: March 26, 2020, 12:25:57 AM »
I built ver2 and followed the diagram not connecting an extra wire to the chorus depth pot ,when I eventually connected the extra wire there was hum ,Ihave built the TDA version .With a switchmode PS there is hum with a regulated supply just a little but as was mentioned here mine sound more like a tremelo with low end thump in chorus more vibe mode is great Earlier in the year Scruffie pointed out that the voltage requirement of the respective BBD's is very close but not identical. In most cases it would be fine, but due to the slight variance in tolerance from one chip to the next from the same batch (similar to how a batch of 100uf capacitors can measure anywhere from 80 to 120 or the hfe of transistors vary from one to the next), there may be rare instances where one particular chip may sound like it isn't quite tuned in well enough (& no trimpot in the CE1 design to tune in the BBD). Simply swapping it for another chip would likely sort it out as it would only rarely happen within the extreme end of the range. Ideally a resistor or two could possibly be replaced with a trimpot to better take care of it so it never happens at all.
I think this  circuit does need a trim pot !!!!with a 25k intensity pot  it helps but not  a perfect chorus