Resistance readings off [resolved]

denti alligator · 809

0 Members and 1 Guest are viewing this topic.

Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
on: January 01, 2024, 11:11:49 AM
There are a few resistance readings that seem odd to me.

Terminal 9 reads 39.6k (terminal 19 reads 10k, as it should). I’ve reflowed this terminal with no difference.

A5 and A6 are about 24.93k, which I know is within range, but B5 and B6 read 105.2k

Also A3/A4 and B3/B4 had readings; they were not showing OL.

Note: I’ve reflowed all these and checked them carefully. Adjusting the balance pot appears to affect the numbers. Maybe that accounts for the discrepancy? (Vol and balance definitely change these numbers… Is that to be expected? Can I move on to the voltage check?)
« Last Edit: January 03, 2024, 11:50:53 AM by denti alligator »

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19369
Reply #1 on: January 01, 2024, 03:48:45 PM
Terminal 9 reads 39.6k (terminal 19 reads 10k, as it should). I’ve reflowed this terminal with no difference.

Which terminal did you reflow? There are lots of terminals that need to be solid for the 10K resistance of the pot to be readable at that terminal.  I would bet you have a bad solder joint on one end of one of the black wires connecting to the level of the volume pot feeding that terminal.  It is really important to resolve this before powering up your Moreplay and trying to use it.
A5 and A6 are about 24.93k, which I know is within range, but B5 and B6 read 105.2k
This could well be the same problem as the issue at terminal 9.
Also A3/A4 and B3/B4 had readings; they were not showing OL.
What are the readings?

I would not power this one up, it's totally possible that you'd end up with excessive DC voltage on the center pin of the right RCA output jack, which is no bueno.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #2 on: January 01, 2024, 03:57:33 PM
Thanks. I’ll go back to this tomorrow and report back. I reflowed 9 and whatever terminals were directly connected to it, maybe just the volume pot. What other terminals should I check to be sure?

These readings all fluctuated pretty signifanctly when I adjusted the volume and balance.

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19369
Reply #3 on: January 01, 2024, 03:59:08 PM
You probably have a flaky ground connection.  These are the black wires.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline hmbscott

  • Full Member
  • ***
    • Posts: 100
Reply #4 on: January 01, 2024, 04:01:56 PM
I recommend you post a picture that shows the connections between the volume pot and the balance pot. There might be a misconnection in the ground wires, the black ones between the two pots. Or maybe in the twisted red/black wires at T2/A6, so a second shot of the A socket wiring would also help.

Scott
[Ortofon 2M Bronze > U-Turn Theory > Eros II] & [iMac via USB > Denafrips Ares 2] >> Moreplay >> Schiit Lokius EQ >> Stereomour II >> Hsu ULS-15 Sub >> homemade DML Speakers
Moreplay 2nd out >> [Crack + Speedball > HD 650]


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #5 on: January 02, 2024, 03:01:50 AM
Ok, I reflowed T9, top and bottom front of vol pot, top and bottom front of balance, bottom rear of balance, and T2.

A3 1.2m and sinking
A4 1.1m and sinking
A5 21k
A6 20.8k

B3 1.07m and sinking
B4 1.02m and sinking
B5 59.8k
B6 59.6k

T9 79.2k


« Last Edit: January 02, 2024, 03:09:12 AM by denti alligator »

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19369
Reply #6 on: January 02, 2024, 05:46:49 AM
You are definitely missing a wire in the region of the volume/balance pot.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #7 on: January 02, 2024, 05:54:15 AM
Do my pictures help you see what’s missing? I can’t seem to see what’s wrong.

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19369
Reply #8 on: January 02, 2024, 05:55:43 AM
Yes, you are missing a black wire in your volume pot/balance pot wiring.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #9 on: January 02, 2024, 06:04:27 AM
Can you tell me where? I have two: one connecting top near tabs and one connecting bottom rear balance to bottom front vol. I must be overlooking another, because I don’t see one in the manual.

Never mind. I see it. I have the twisted pair on the bottom of the balance pot on the wrong lugs.
« Last Edit: January 02, 2024, 06:08:39 AM by denti alligator »

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #10 on: January 02, 2024, 07:20:01 AM
All well now, thanks for your help! Voltages were on. But the left channel is out. Troubleshooting now. Any tips?

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #11 on: January 02, 2024, 07:32:30 AM
This is just a signal path wiring issue. But it’s on all three inputs and both outputs. When I turn the Moreplay off it still only sends the R signal to my Stereomour.

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19369
Reply #12 on: January 02, 2024, 08:24:48 AM
All well now, thanks for your help! Voltages were on. But the left channel is out. Troubleshooting now. Any tips?
While it looked like you were missing a wire between the volume and balance pots, what I actually see now is that the balance pot just isn't wired in correctly.

I still would not power up your amp until terminal 9 is reading the correct resistance.  Literally if you plug this Moreplay into a DC coupled solid state amp and turn it on, you may find a woofer cone departs your speaker cabinets and you have an expensive amp repair to pay for.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline denti alligator

  • Hero Member
  • *****
    • Posts: 1150
Reply #13 on: January 02, 2024, 08:28:34 AM
Resistance reading was normal after the rewire. Just trying to figure out the lack of L channel now.

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19369
Reply #14 on: January 02, 2024, 08:42:22 AM
Check the wiring on your balance pot.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man