I've been pulling out my hair trying to troubleshoot this HM-2 clone. I have no signal when engaged.
I'm using
this layout which I have built before with success.
Here are photos of the boardI tested all of my resistors and capacitors beforehand. I'm using BF244A in place of the BF245 (last one I built that worked I used a BF245B). I'm using TL072CP op amps. I tested with several of each transistor / op amp to make sure one isn't faulty
As someone pointed out when I posted on Reddit (/r/diypedals), I had the 244 oriented wrong (had to switch S and G, then rotate 180) in that photo but I have adjusted and updated the voltages. Still no signal.
You might notice one spot where I made an accidental cut and added a link to fix this on the solder side of the board
I measured the DC voltage to ground:
IC1 (top on layout)
1- 7.9
2- 1.4
3- 4.0
4- 0
5- 3.3
6- 3.3
7- 0.7
8- 8.5
IC2
1- 7.9
2- 7.9
3- 1.3
4- 0
5- 4.0
6- 4.1
7- 4.1
8- 8.5
IC3
1- 4.0
2- 4.1
3- 3.9
4- 0
5- 4.0
6- 4.1
7- 4.1
8- 8.5
BF244A
G- 3.7
S- 5.0
D- 8.5
C2240
E- 0
C- 4.2
B- 0.5
A970
E- 7.7
C- 3.3
B- 7.1
Let me know if I can provide anything else or clarify something