I built this up last night and got nothing. today I swapped the 78l05 for the 7805 that was on the schematic and reflowed everything and I am getting a signal but it sounds like a sitar. very thin sounding and distorted. its broken for sure. I'll keep playing around with it and report back if I figure it out.
so the sitar noises were definetly due to a dodgy pt2399. I tested a few others just to confirm I had working ones now, however still no luck. I'm not getting any lfo noise at all, and when I flip the voice switch it just turns the signal off.. anyone smarter have any ideas?
Have this on a breadboard and was having the same problems. After looking at the schematic I found that the 470k resistor on the second pt2399 (ic2) should be connected to pin 16 (just like ic1). This fixed the voice switch cutting off the signal. This layout is also missing a 220k resistor between pins 1 and 3 of the TL072. Effect came to life after these two changes.
I had some difficulty with this build but ultimately got it to work so I wanted to share my experience in case it helps anyone in the future.
At first test, I had a constant high pitched whine at ~3.3kHz. I reflowed all joints, knifed between the strips, changed out some parts (will detail below) but nothing seemed to help.
I was about to call it quits but I thought of one more thing I hadn't troubleshot - the power supply I was using. I have a single 9V wall wart that I use for testing because it's more convenient on my desk. It's typically fine for this purpose so I didn't think much of it. However, when I'm recording, I use a CIOKS DC7 so I can power multiple devices. As soon as I tried the circuit with the CIOKS power supply, the whine disappeared and the circuit sounded great. So in my experience, this circuit may be picky about power. Try that if you're experiencing what I encountered!
Some (probably completely unnecessary) changes I made and kept because I like how it sounds in its current state: - Swapped Q1 with 2N2222A - Swapped IC3 with NE5532
One final note, I tried exchanging the 78L05 with an L7805 (the larger version) and it made no difference so I went back to 78L05 for its smaller size.
This circuit is cool. It's pleasantly lo-fi, leans darkish, and there are quite a few usable voicings available with the addition of the switches. Looking forward to using it.
Best of luck if you're having some difficulty - keep at it, you'll get it right!
Whaaaaat!?
ReplyDeleteClock ticking? Parasit Studio layout has clock ticking, if someone verifies this, please let us know
ReplyDeleteThank you for this layout
ReplyDeleteI built this up last night and got nothing. today I swapped the 78l05 for the 7805 that was on the schematic and reflowed everything and I am getting a signal but it sounds like a sitar. very thin sounding and distorted. its broken for sure. I'll keep playing around with it and report back if I figure it out.
ReplyDeleteso the sitar noises were definetly due to a dodgy pt2399. I tested a few others just to confirm I had working ones now, however still no luck. I'm not getting any lfo noise at all, and when I flip the voice switch it just turns the signal off.. anyone smarter have any ideas?
DeleteHave this on a breadboard and was having the same problems. After looking at the schematic I found that the 470k resistor on the second pt2399 (ic2) should be connected to pin 16 (just like ic1). This fixed the voice switch cutting off the signal. This layout is also missing a 220k resistor between pins 1 and 3 of the TL072. Effect came to life after these two changes.
ReplyDeleteThanks for spotting those mistakes. Added the 220 and moved the 470k resistor. Layout is updated.
DeleteThanks a lot PK! Can confirm this fixed my issues as well! Legendary! also I'm not getting any bleed through from the clock
DeleteFinally took this off the breadboard and soldered it using the updated layout. You can tag this one as verified.
DeleteThanks PK! Tagged.
DeleteI had some difficulty with this build but ultimately got it to work so I wanted to share my experience in case it helps anyone in the future.
ReplyDeleteAt first test, I had a constant high pitched whine at ~3.3kHz. I reflowed all joints, knifed between the strips, changed out some parts (will detail below) but nothing seemed to help.
I was about to call it quits but I thought of one more thing I hadn't troubleshot - the power supply I was using. I have a single 9V wall wart that I use for testing because it's more convenient on my desk. It's typically fine for this purpose so I didn't think much of it. However, when I'm recording, I use a CIOKS DC7 so I can power multiple devices. As soon as I tried the circuit with the CIOKS power supply, the whine disappeared and the circuit sounded great. So in my experience, this circuit may be picky about power. Try that if you're experiencing what I encountered!
Some (probably completely unnecessary) changes I made and kept because I like how it sounds in its current state:
- Swapped Q1 with 2N2222A
- Swapped IC3 with NE5532
One final note, I tried exchanging the 78L05 with an L7805 (the larger version) and it made no difference so I went back to 78L05 for its smaller size.
This circuit is cool. It's pleasantly lo-fi, leans darkish, and there are quite a few usable voicings available with the addition of the switches. Looking forward to using it.
Best of luck if you're having some difficulty - keep at it, you'll get it right!