Recent content by hamerfan

I double checked it too. Most sources say GE, but this standard reference book states S. To me all vintage black glass diodes were Ge, but certainly there a lot of silicons amongst. Funny enough my stash of Valvo OA5 and OA7 diodes are not even mentioned in this book. Maybe they are fake?!?

@MichaelW Hate to be the partypooper, but my my to go reference https://www.worldradiohistory.com/UK/Bernards-And-Babani/Babani/108-Michaels-International-diode-equivalents-guide.pdf says CV7364 to be american made silicon like european AAZ12

Best use an additional board like this https://guitarpcb.com/product/dpdt-wiring-board/ with a on/off/on switch. Wire the LEDs to the main board, they have the highest Vf.

https://forum.pedalpcb.com/members/michaelw.7705/showcase

123 or DSG left to right, if i am not mistaken.

Genuine TL072? There are a lot of fakes on the market. Read here: https://forum.pedalpcb.com/threads/tl072cp-op-amp-differences.21131/

For a very short time i was the soundman of a band with a harmonica player. He used a tube preamp the HK Crunchmaster or HK Tubeman to go into the PA. I used a low gain tube in it, a12au7 or something. Sounded pretty good.

I rebiased my build after giving it to a friend. I had it with 9 and 12v, but my friend has a 9v only board. He said the sound has improved after the bias.

Always go with the sockets in the case of ICs. Nobody needs the stress desoldering an IC. The OPA2134 is maybe a bit overkill in an overdrive, but at that time the Hermida was developed they still were affordable.

Check the values of r6 and r7, if they are right take a lower r6. BTW the NPN should have a positive voltage.

yeah its a mixture of PNP and NPN transistors which makes me think of a problem of the pinouts

Mine works great, maybe on a strat it is a bit trebly with a MP38a of hfe 62. What your favourite hfe for this application?

Faulty silicon trans? Did you check it with a Tester?

Low leakage only on the first transistor necessary. The second transistor with the higher hfe has often more leakage by nature.

I am not in position to explain everything, but i found the circuit analysis of electrosmash useful to understand the basics. https://www.electrosmash.com/big-muff-pi-analysis I also saw some vids of Brian Wampler on this topic.