help troubleshooting a high pitched tone from Sony PS-X600

[FatsLeDieux]

I've been on the prowl for one of these for a while and finally scored a good condition one, but in the last week it's developed a really odd high-pitched tone that I'm having trouble tracking down - so I'm reaching out to the community for troubleshooting ideas.

here's what I've been able to determine:
• The noise only seems to happen when the tonearm is lowered on a spinning record OR when it's moving back and forth from the tone-arm rest (during automatic start / stop).
• It's a single frequency every time
• Grounding seems to be good
• My other Turntable using the same cartridge / receiver / speakers is fine.
• Cartridge connections on the Sony appear to be good and I've carefully aligned the cartridge and set balance / anti-skate (1.5 g)

I'm not sure what to try next - has anyone experienced something similar or have any suggestions? Thanks!

 

[cre009]

You don't hear the sound until the tonearm is lowered because of a mute switch.

Try pressing the manual arm lowering with arm in the rest and you should then hear the sound. Makes it easier to check if fixes work.

There are a few potential causes and you should be able to find posts at this site and at Vinylengine (in Sony subsection) that discuss them.

Mine has the issue caused by the RCA leads where they exit the turntable that leads to the humming. It indicates a possible connection problem inside the deck or with the cable but I can prevent the issue by making sure that the RCA leads are horizontal where they exit the deck. I do this by propping a small box under the cable at exit.

 

[FatsLeDieux]

I didn't think of the mute switch, that's a good tip. will mess around with it after work tonight (I'm definitely not troubleshooting my turntable while in the office

 

[mackat]

I just got a PS-X600 in really lovely overall condition, but I am also having this problem, unfortunately. It is what sounds like an extremely high pitched whine that is audible when the muting relay is not active. It is loud enough to be perceived when music is playing and affects the quality of music. Sometimes, a louder intermittent whine occurs while the record is playing. These noises seem to have something to do with the tonearm servo, but I don't understand why this noise would be injected into the signal path. I have attached a FLAC file of me lowering the tonearm onto a stopped record, as well as a zoom in of what it looks like in Audacity.

Thanks!
Ben

https://www.dropbox.com/s/daq9fecib7njdni/PS-X600 whine.flac?dl=0

 

[mackat]

Any ideas? Unfortunately, this turntable is basically unlistenable because the high pitched noise is easily detected over the music. It’s so high pitched that you almost don’t hear it, but it is ear splitting at the same time (you can hear it if you listen to the above file). I know this turntable is ridiculously complicated electronically, which doesn’t help. Maybe a bad muting relay (although it does work)?

Another thing is that the “Locked” light sometimes flashes off for a second during playback, but I checked the speed with my RPM app and the speed/W&F is completely unaffected, so it doesn’t appear to actually lose the quartz lock.

 

[FatsLeDieux]

Mackat, thanks for sharing your experience and the detailed image. Sounds like we have a similar issue and I have yet to resolve mine. I've tried cleaning contacts and adding a drop of lubricant on the motor shaft, but haven't been brave enough to disassemble the tonearm. All other functions including muting relay appear to function normally.
Anything else I learn I'm happy to share, but am no expert!

 

[ETI_5000]

Sony Service Bulletin No. 148 (1982), Models PS-X500 & PS-X600.
Subject: Induced noise from the cartridge. (I suspected it was induction, as Mackat's recording shows that the noise level is exactly the same in both channels.)
Symptom: Cartridge produces noise while playing.
Cause: Some motors, depending upon the impedance of the coil, may generate an abnormal amount of flux when driven from a high-gain amplifier.
Remedy: Change the following resistors. (The particular resistors are in the main platter drive motor control circuitry, by the way, not the arm control motors.)

The resistors which need to be changed, all on the main PCB in the two turntables, all 1/4W carbon film (metal film will also be OK, but cost more), are as follows.

PS-X600:
R237 and R238 (change from 10kΩ to 27kΩ)
R245 (change from 100kΩ to 68kΩ)

PS-X500:
R199 and R200 (same values as R237 and R238 above)
R205 (same values as R245 above)

See picture below, showing locations of the resistors on the PS-X600 PCB, and the part numbers and values to be changed.



So it may be that those resistors may not have been changed on your turntables.

I hope that helps - let us know how you get on.

 

[FatsLeDieux]

@ETI_5000 thanks for that information, will update once I get a chance to dig into this.

 

[mackat]

Sony Service Bulletin No. 148 (1982), Models PS-X500 & PS-X600.
Subject: Induced noise from the cartridge. (I suspected it was induction, as Mackat's recording shows that the noise level is exactly the same in both channels.)
Symptom: Cartridge produces noise while playing.
Cause: Some motors, depending upon the impedance of the coil, may generate an abnormal amount of flux when driven from a high-gain amplifier.
Remedy: Change the following resistors. (The particular resistors are in the main platter drive motor control circuitry, by the way, not the arm control motors.)

The resistors which need to be changed, all on the main PCB in the two turntables, all 1/4W carbon film (metal film will also be OK, but cost more), are as follows.

PS-X600:
R237 and R238 (change from 10kΩ to 27kΩ)
R245 (change from 100kΩ to 68kΩ)

PS-X500:
R199 and R200 (same values as R237 and R238 above)
R205 (same values as R245 above)

See picture below, showing locations of the resistors on the PS-X600 PCB, and the part numbers and values to be changed.

View attachment 1918638

So it may be that those resistors may not have been changed on your turntables.

I hope that helps - let us know how you get on.

I really appreciate you posting this, I certainly would never have figured it out otherwise. I will have to take a look and replace the resistors, which will hopefully fix the problem. I will post again once I have done so.

 

[rrobot]

This is exactly the same on my x500! Fantastic work, basically the Tuntable has been unusable for me. Can anyone report that it fixes the symptoms?

 

[mackat]

This is exactly the same on my x500! Fantastic work, basically the Tuntable has been unable for me. Can anyone report that it fixes the symptoms?

Unfortunately, the suggested fix is above my pay grade. As soon as I opened the unit up, I knew I did not want to risk damaging anything. If anyone that lives in the San Diego area and is more knowledgeable about electronics than I am wants to see if they can resolve the issue, please let me know.

 

[rrobot]

Sadly I'm a long way from san Diego! I'm not that great on the iron either but was hopeful I could swap a few resistors. Did the same on my sl1200. Are the boards pretty gnarly and hard to access?

 

[THF2]

I am the original owner of one of these unique and most excellent TT’s.

While I have not experienced the same issue that has been reported in this thread (knocking on my head for good luck!), I have contemplated trying to do a cleanup and repair of the various components in this device (i.e the lamp the determines the size and speed of the disc does not work). Needless to say, the complexity of this product is enough to intimidate a novice restorer such as myself. This TT is truly a PITA to work on (as @mackat states above) and I have to build up the courage to go into the “belly of the beast”!

 

[rrobot]

have to build up the courage to go into the “belly of the beast”!

It certainly looks like a serpents nest of plugs and cables and everything else. It seems to hinge on being able to remove the main board... Wonder if anyone who's done it can comment?

 

[rrobot]

Needless to say, the complexity of this product is enough to intimidate a novice restorer such as myself. This TT is truly a PITA to work on (as @mackat states above) and I have to build up the courage to go into the “belly of the beast”!

From looking at the main board, it seems the main deterrent is the maze of wires and connectors emanating from it. Some of them are header connectors which should be easy to relocate but there seem to be a lot of wires just soldered straight into through holes. Short of snipping off the offending resistors leaving some leads exposed and soldering the new values on top of the board (doesn't sound ideal tbh) I wonder if there's enough slack to flip the board up still attached? Perhaps this is a job for an experienced tech.

 

[THF2]

From looking at the main board, it seems the main deterrent is the maze of wires and connectors emanating from it. Some of them are header connectors which should be easy to relocate but there seem to be a lot of wires just soldered straight into through holes. Short of snipping off the offending resistors leaving some leads exposed and soldering the new values on top of the board (doesn't sound ideal tbh) I wonder if there's enough slack to flip the board up still attached? Perhaps this is a job for an experienced tech.

I am tending to agree with you as I am a bit “heavy handed” when it come to these sorts of projects.

After reviewing the service manual in great detail, I feel like I am going to get bitten by a rattler when I enter the dark cave.

 

[rrobot]

I feel like I am going to get bitten by a rattler when I enter the dark cave.

Indeed! I'm still going to give it a crack I think when I get time to pull the base off...nothing ventured and all that. Sony surely intended it to be serviceable, especially if they continued to issue service bulletins? If it looks like I'll never get the board back together I'll abort!

 

[THF2]

Indeed! I'm still going to give it a crack I think when I get time to pull the base off...nothing ventured and all that. Sony surely intended it to be serviceable, especially if they continued to issue service bulletins? If it looks like I'll never get the board back together I'll abort!

Please keep us all (especially me!) posted on your progress.
I will admit that I am usually the one that goes over the wall 1st but in this case, I will leave that heroism to you!

 

[rrobot]

Please keep us all (especially me!) posted on your progress.
I will admit that I am usually the one that goes over the wall 1st but in this case, I will leave that heroism to you!

I shall certainly do so! I've a bad feeling that once the covers come off, my bravado may evaporate!