Recent Posts

31

Mainline / Re: Mainline Questions

« Last post by Tabaia on May 17, 2025, 09:16:28 PM »

Great !Im on track.
Thank you.

32

Stereomour II / Re: Failed Final Voltage Check

« Last post by Paul Birkeland on May 17, 2025, 04:12:31 PM »

Did you plug one of the 2A3s in with one or both of the fat pins in the wrong holes?  If so, you're going to need to check the 130 Ohm 2W resistors in the power supply to see which one(s) you cooked.  The socket contacts may also need to be bend back together a little bit to grab on the skinny pins again.

33

Stereomour II / Failed Final Voltage Check

« Last post by figby on May 17, 2025, 09:01:08 AM »

Passed the resistance check, but failed the voltage check. I've walked back through the build, checked solder joints, etc. but can't find the issue. Any thoughts on where to look?

1. 365 VDC (-20mv)
2. 395 VDC (0)
3. 0 VDC (0)
4. 0 VDC (0)
5. 0 VDC (0)
6. 58 VDC (40.2mv)
7. 170-230 VDC (-.9v)
8. 0 VDC (0)
10. 0 VDC (-363mv)
11. 0 VDC (0)
13. 0 VDC (0)
14. 170-230 VDC (206.8v)
15. 58 VDC (60v)
16. 0 VDC (0)
17. 0 VDC (10mv)
18. 0 VDC (0)
19. 395 VDC (395v)
20. 365 VDC (365v)
21. 58 VDC (38mv)
22. 58 VDC (38mv)
23. 0 VDC (0)
24. 58 VDC (38mv)
25. 58 VDC (38mv)
26. 0 VDC (0)
27. 390 VDC (0)
28. 0 VDC (0)
29. 0 VDC (0)
30. 398 VDC (409v)
31. 399 VDC (402v)
34. 392 VDC (394v)
35. 0 VDC (0)
36. 58 VDC (61v)
37. 58 VDC (61v)
38. 0 VDC (0)
39. 58 VDC (61v)
40. 58 VDC (61v)

34

Moreplay / Re: 20 Ohms at 9

« Last post by Dread31 on May 16, 2025, 01:58:32 PM »

The wiring is there that should allow this resistance to appear correctly.  What I do see is a lot of joints that just don't have enough solder on them. 

Paul, it turns out I had the red wires on both tube sockets wired A5 & B5. Moved both to A6 & B6 where they belong. Problem solved, sounds wonderful. I did also find three weak solder joints and re-flowed them, adding a bit of solder as well.

Thank you for your time and assistance, Kind Sir.
Bottlehead is truly a class act.

Dave Read

35

Mainline / Re: Mainline Questions

« Last post by Paul Birkeland on May 16, 2025, 04:41:35 AM »

Yes, all is well.   The voltage at that node will be relatively high when there's nothing built in the amp to load it down.

36

Mainline / Re: Mainline Questions

« Last post by Tabaia on May 15, 2025, 05:59:00 PM »

What AC line voltage initially measured between 230 and 247
I used the wiring for Greater than 235V and Less than 245V.

Also Reading the manual and getting my head around this i realise that the reading I have for the board 235V is probably OK.
Manual says it should read between 300-500VDC , mine reads 366VDC.
I assume that is fine?

37

Moreplay Upgrade / Re: A few more kits available

« Last post by Doc B. on May 15, 2025, 11:40:00 AM »

Can this be used to replace the volume knob in the Crack? I forgot the value of the pot there...

This has a completely different resistance, taper and application (for balance rather than volume).

38

Moreplay Upgrade / Re: A few more kits available

« Last post by Happy Ghost on May 15, 2025, 10:04:32 AM »

If anyone is looking for a very high quality 10K balance pot for DIY projects we have quite a few for sale at $25 each.

Can this be used to replace the volume knob in the Crack? I forgot the value of the pot there...

39

Moreplay Upgrade / Re: A few more kits available

« Last post by Doc B. on May 15, 2025, 09:51:12 AM »

Arrgh. I accidentally ordered the wrong pots. Shoulda been log taper for volume, but I accidentally ordered pots with an MN balance taper. Yes I have a palm print on my forehead. Thankfully I discovered the error before we started shipping the new batch of ugrade kits. We found the correct part and we have them coming expedited. This will create a delay of a few extra days before we begin shipping. Apologies.

If anyone is looking for a very high quality 10K balance pot for DIY projects we have quite a few for sale at $25 each.

40

Stereomour II / Re: Stereomour II upgrades

« Last post by hmbscott on May 15, 2025, 09:33:28 AM »

I installed the Shunt Regulator first. I bought it with the Kit, but waited a couple of months to install it. A few months later I bought and installed the DC Filament kit. Of the two, the DC filament was the more impactful because I was dealing with audible heater hum (very efficient speakers). Probably because of the hum issue downed it out, I don't recall the shunt regulator making a huge sonic change. It's been more than a year though and memory fades. I built my Stereomour II as a straight up amp and deleted all the preamp features so the stepped attenuator kit isn't applicable to mine.

If I had to do it again I'd definitely install the DC filament kit first.

It's a tossup whether I'd install the shunt regulator or the stepped attenuator next, assuming a stock unit. Maybe the stepped attenuator, because it seems like it might benefit from more open access during the install. Although having said that, the Shut Regulator board mounts under the power transformer, so should be well out of the way of the Stepped Attenuator.