The Amp Garage

Looks very good, great work! I see you indicated 6V6s and a PT secondary of 260v-0-260v I assume your PCB would also work with EL34s and a PT secondary of 300v-0-300v?

Good idea, thanks! I’ll check that out.

For now, it seems that I got super lucky. I installed a PPIMV and I believe the noise is gone now. I only played for like 15 minutes but it did not appear. Let’s see if it comes back. Many thanks to you all of you for the help!!

Edit: it’s still there

:lol: :lol: it is not permanent , to everybody is clear. it is here to block DC from the cathode and see if the popping is from silver mica. after the wire will be returned back to pin 8. Thanks! I installed new silver mica but it did not make any changes either. Edit: I chopsticked the amp again b...

So, I had the chance to have a quick look at amp again. I made sure that no resistors on the board are touching each other as pointed out here before but this did not change anything. I also followed bepone‘s advise and bypassed the volume pot without success. I also changed the 100k resistor that s...

Thanks for sharing this. I really hope it’s not the OT. It is brand new and I doubt that I cooked it somehow. But of course it could have been faulty when I received it…

I hope I can update you guys this weekend!

[quote=Riffmonster post_id=442619 time=<a href="tel:1656935393">1656935393</a> user_id=18952] Thanks a lot for your help and input. Unfortunately, I had ruled out the standby switch earlier. The problem was still there after I removed the standby switch. Also, the pop appears randomly and not switc...

Thanks a lot for your help and input. Unfortunately, I had ruled out the standby switch earlier. The problem was still there after I removed the standby switch. Also, the pop appears randomly and not switching-related. I am still away from the amp but I still hope I’ll be able to solve the problem w...

Just to confirm, the problem disappears when you remove V3, what about if you remove V2? You said earlier the problem just gets quieter if you remove it, is that right? Yes that is correct. What valve are you using for V2? As most russian valves can't handle the high heater to cathode voltage. I've...

I think they are touching, yes. I will change it and check if the insulation or enamel is damaged.

Btw, the trick with 10k on pin 3 of the V2 only worked because it reduced the overall volume of the amp. That’s why the pop seemed less loud too…

Thanks all for your help!!

Interesting! I have maybe played for an hour or so only, do maybe I let it rest a bit now and just play. Also, the pop tends to appear less frequently when the amp is warm after like 5-10 minutes.

I just shortly put the silver micas on the 100ks but that did not change anything, so I removed them again. Increased the resistor at pin 3 to 33k but not much difference either. The pop is still there but as I said at a lower volume now.

Thanks a lot for this tip. I put a 10k resitor at pin 3 and it reduced volume of the pop a bit! I have to check if I still have some 100pf caps here. If not, I will order them. Can I leave the 10k in when I add the two 100pf caps?

EDIT: I only have two 220pf silver mica, still worth trying?

Thanks! I changed both silver mica caps and the 680nf cap but nothing changed. The wire going to pin 3 of V2 is definitely microphonic when lightly hitting it with a chopstick. I wish I had an oscilloscope… any other ideas? Otherwise I might have to surrender and bring it to a tech. It’s a shame bec...

Thanks both for your tips. 1. The problem persists and even got worse when I put a 150k 2 watt resistor in parallel to the 100k resistor depicted. 2. Yes, I cleaned that up on the filter cap right after the photo. The wires are unused PT wires, you could use the PT also for 120 and 220v. I triple he...

I don't think that is the issue since I have used these switches in many builds in the exact same way.

Really frustrating issue, can't figure it out at all.