HELP! Screeching from SEX

denti alligator · 8924

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Offline denti alligator

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Reply #30 on: December 25, 2012, 11:19:26 AM
I have a couple 152k resistors on some old C4S boards, but they have really short leads. I guess I could make them longer with some wire. The other resistors I have are much lower.

- 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

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Reply #31 on: December 25, 2012, 11:21:51 AM
Temporarily resolder this resistor between 38 and 39, then see if the screeching persists at startup.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline denti alligator

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Reply #32 on: December 25, 2012, 11:25:33 AM
Alright, I'm trying that now. You know what you're doing better than I, but keep in mind that the noise when prodding solder joints was at 36 and 37.

- 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

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Reply #33 on: December 25, 2012, 11:40:58 AM
OK, resistor in place. I turned it on without phones or speakers plugged in and I'm not hearing the screeching (which was completely audible even WITHOUT phones or speakers attached). So I guess I'll test with speakers next.

What does this tell you, PB?

- 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

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Reply #34 on: December 25, 2012, 11:48:43 AM
Tried it with phones: no screeching. Hardly any sound in the left channel, but I'm assuming that's the resistor's fault. So what next?

By the way: THANK YOU for helping me on Xmas day. I'll try not have this solved by tomorrow, so you can celebrate Kwanzaa in peace :)

- 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

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Reply #35 on: December 25, 2012, 11:57:50 AM
Remove the resistor, turn the volume pot all the way down, measure the resistance between 38 and 39.

You either have a bad solder joint in the wiring between the input jack(s) and each tube (running through the volume pot), or the pot is defective.

There is no reason to assume that the pot is defective without measuring it to check (they generally take a long, long time to wear out).

If the resistance between 38 and 39 is not zero when the pot is all the way down, let us know. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline denti alligator

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Reply #36 on: December 25, 2012, 12:12:18 PM
It's definitely not zero. Depending on where I put the MM leads, it reads between 1.7 and 1M. I can't seem to get a stable reading. What does this tell you?

- 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

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Reply #37 on: December 25, 2012, 12:37:58 PM
Does it help to know that the screeching in unaffected by the volume pot (turning it up or down)? Also, it happens whether or not there is anything coming from (or even plugged in to) the inputs?

If I need to recheck the solder joints from the input to the tube, what path is that so I can start reflowing? Thanks.

- 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

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Reply #38 on: December 25, 2012, 12:51:44 PM
Quote from: denti alligator on December 25, 2012, 12:37:58 PM

If I need to recheck the solder joints from the input to the tube, what path is that so I can start reflowing? Thanks.

Follow the wires leaving the RCA jacks...


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline denti alligator

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Reply #39 on: December 25, 2012, 01:00:28 PM
I'm afraid I'll need a little guidance. I see the left input going to the headphone jack and from there it appears to go to 25 and 30, but the trail ends there for me. I see the wires coming from the transformers, and I see the ground buss. But that's it. I'll start with 25 and 30, but I'm assuming the path is longer than this.

Is it not possible that the cap at 36 and 37 is somehow to blame? It's the one that makes horrible noise when I jab at those joints.

- 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 earwaxxer

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Reply #40 on: December 25, 2012, 01:00:50 PM
Lots of screeching sex talk here! Sorry, I guess I'm being insensitive to those with the issue.... Couldn't help it.  Well maybe I could have. Who fucking cares. Ok, I'm done.

Eric
Emotiva XPA-2, Magnepan MMG (mod), Quickie (mod), JRiver, Wyrd4sound uLink, Schiit Gungnir, JPS Digital power cord, MIT power cord, JPS Labs ultraconductor wire throughout, HSU sub. powered by Crown.

Offline denti alligator

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Reply #41 on: December 25, 2012, 01:34:28 PM
Reflowed 25 and 30 and then 37 and 38 again. Now getting a resistance reading of 3 between 37 and 38. No screeching. So I'm at least able to listen to some tunes. I'll guess I'll wait til it starts screeching again to post here, unless someone has advice before that (inevitably?) happens again.

- 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

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Reply #42 on: December 25, 2012, 01:46:49 PM
Sounds like there was a bad solder joint, keep us posted.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline earwaxxer

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Reply #43 on: December 25, 2012, 01:53:45 PM
agreed - bad solder joint is frequently the prob. I have been calling the police for a couple of week because 'someone' has been ringing my doorbell. Well, duhh, its a bad connection!

Eric
Emotiva XPA-2, Magnepan MMG (mod), Quickie (mod), JRiver, Wyrd4sound uLink, Schiit Gungnir, JPS Digital power cord, MIT power cord, JPS Labs ultraconductor wire throughout, HSU sub. powered by Crown.

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