Hey Anders - I finally gave this one a try and at first, I almost got the chorus sound to work. As I moved the depth pot back and forth, the modulation would come and go but not stay. And the rate knob didn't appear to have any effect. Then I noticed I had the 1uF capacitor above the JRC4558 backwards. And when I flipped it, the modulation disappeared altogether. I'm going to compare the signal path to the tagboard layout (which I have built successfully) and see if I can find any discrepancies.
Okay - I think I may have damaged my LM358 - it was heating up. I see that the tagboard layout does not have input or output pull down resistors, or diode protection. Which shouldn't matter - but the main difference I'm seeing so far is non-polarized caps instead of electrolytics for all the 1uF capacitors. This seems like it shouldn't matter but I thought I'd bring it up anyway... there are a lot of interconnected bits in this circuit, but I'm going to keep looking at the two of these layouts anyway.
Hey Chris! Did you ever got your build working properly? The electro caps is per the original schematic. And the added polarity protection and the pulldown resistor don't affect theoperation of this circuit.
Got some MN3007s in the mail and I'm eager to build this!
I built this pedal and did the mix modification, replacing the 20K and 22K resistors with a B50K potentiometer and it works. The only problem: there is a volume increase in the extreme dry/wet positions. Any suggestion?
Hmm...I really don't know how to add a Mix pot. It is worth tking a look at the Boss CE-2 layout which I uploaded yesterday since these two are quite similar in topolgy except for the clock driver part.
Hey Anders - I finally gave this one a try and at first, I almost got the chorus sound to work. As I moved the depth pot back and forth, the modulation would come and go but not stay. And the rate knob didn't appear to have any effect. Then I noticed I had the 1uF capacitor above the JRC4558 backwards. And when I flipped it, the modulation disappeared altogether. I'm going to compare the signal path to the tagboard layout (which I have built successfully) and see if I can find any discrepancies.
ReplyDeleteBrave of you to tackle this one, Chris!
DeleteVery kind of you to double check the the layout.
Okay - I think I may have damaged my LM358 - it was heating up. I see that the tagboard layout does not have input or output pull down resistors, or diode protection. Which shouldn't matter - but the main difference I'm seeing so far is non-polarized caps instead of electrolytics for all the 1uF capacitors. This seems like it shouldn't matter but I thought I'd bring it up anyway... there are a lot of interconnected bits in this circuit, but I'm going to keep looking at the two of these layouts anyway.
ReplyDeleteHey Chris!
DeleteDid you ever got your build working properly? The electro caps is per the original schematic. And the added polarity protection and the pulldown resistor don't affect theoperation of this circuit.
Got some MN3007s in the mail and I'm eager to build this!
I built this pedal and did the mix modification, replacing the 20K and 22K resistors with a B50K potentiometer and it works.
ReplyDeleteThe only problem: there is a volume increase in the extreme dry/wet positions. Any suggestion?
Hmm...I really don't know how to add a Mix pot. It is worth tking a look at the Boss CE-2 layout which I uploaded yesterday since these two are quite similar in topolgy except for the clock driver part.
DeleteOther than that, I guess I should tag it?