A strange issue with my "new" Sansui QRX-9001. Any ideas?

[gvl_guy]

I just bought a QRX-9001, fully restored, from the QRX Restore. It's a beautiful piece of equipment and I'm in love! But it's doing something a little strange.

When I power it up, there a strange flutter/buzz that's mainly coming from the right front speaker. No changing dial positions or inputs make any difference. Even changing speakers to the B outputs didn't change anything. What does affect it is the 4 channel selector buttons. It's not as noticable in CD-4/discrete and very noticeable in SQ. QS is kind of in between.

After playing around with things and emailing with owner Justin, we've both determined it's likely some kind of interference. (I've had it for a month or so and it's only developed in the past week or so, even though nothing has changed around my setup.) I unplugged EVERYTHING nearby; TV, TiVo, Oppo player, phone, lamp, clock, modem. I even moved the receiver over about a foot. Nothing changes.

The only thing I accidentally found was that if I hold my hand in the middle of the left side wooden panel, (not toward the back or front,) it stops.

Does anyone have any thoughts as to 1) what could be causing this and 2) what I can do to stop it? I can't stand next to it and hold my hand near the panel when I want to listen.

Edit. I guess the file is too big to attach. So here is a link if you'd like to hear it.

https://drive.google.com/file/d/1k8Zs7DQwE9_Cxrpq1Abvk1hT9m-MZd4V/view?usp=drivesdk

 

[Sonik Wiz]

I just bought a QRX-9001, fully restored, from the QRX Restore. It's a beautiful piece of equipment and I'm in love! But it's doing something a little strange.

When I power it up, there a strange flutter/buzz that's mainly coming from the right front speaker. No changing dial positions or inputs make any difference. Even changing speakers to the B outputs didn't change anything. What does affect it is the 4 channel selector buttons. It's not as noticable in CD-4/discrete and very noticeable in SQ. QS is kind of in between.

After playing around with things and emailing with owner Justin, we've both determined it's likely some kind of interference. (I've had it for a month or so and it's only developed in the past week or so, even though nothing has changed around my setup.) I unplugged EVERYTHING nearby; TV, TiVo, Oppo player, phone, lamp, clock, modem. I even moved the receiver over about a foot. Nothing changes.

The only thing I accidentally found was that if I hold my hand in the middle of the left side wooden panel, (not toward the back or front,) it stops.

Does anyone have any thoughts as to 1) what could be causing this and 2) what I can do to stop it? I can't stand next to it and hold my hand near the panel when I want to listen.

Edit. I guess the file is too big to attach. So here is a link if you'd like to hear it.

https://drive.google.com/file/d/1k8Zs7DQwE9_Cxrpq1Abvk1hT9m-MZd4V/view?usp=drivesdk

I tried getting your audio file. First odd thing is google drive asked me to sign in. Then it said I need permission to access that file. Then I clicked on "request permission." It said a request has been sent, presumably to you.

I use Dropbox myself, but have accessed many others google drive's for sharing files. I've never run into this before. Hmmm...

 

[DuncanS]

I just bought a QRX-9001, fully restored, from the QRX Restore. It's a beautiful piece of equipment and I'm in love! But it's doing something a little strange.

When I power it up, there a strange flutter/buzz that's mainly coming from the right front speaker. No changing dial positions or inputs make any difference. Even changing speakers to the B outputs didn't change anything. What does affect it is the 4 channel selector buttons. It's not as noticable in CD-4/discrete and very noticeable in SQ. QS is kind of in between.

After playing around with things and emailing with owner Justin, we've both determined it's likely some kind of interference. (I've had it for a month or so and it's only developed in the past week or so, even though nothing has changed around my setup.) I unplugged EVERYTHING nearby; TV, TiVo, Oppo player, phone, lamp, clock, modem. I even moved the receiver over about a foot. Nothing changes.

The only thing I accidentally found was that if I hold my hand in the middle of the left side wooden panel, (not toward the back or front,) it stops.

Does anyone have any thoughts as to 1) what could be causing this and 2) what I can do to stop it? I can't stand next to it and hold my hand near the panel when I want to listen.

Edit. I guess the file is too big to attach. So here is a link if you'd like to hear it.

https://drive.google.com/file/d/1k8Zs7DQwE9_Cxrpq1Abvk1hT9m-MZd4V/view?usp=drivesdk

My suspicion would be a dry solder joint somewhere, so you get a higher impedance node which tends to pick-up interference. The capacitance of moving your hand near is possibly enough to supress the problem. The interference source could even be internal in the Sansui, there are oscillators for the CD4, RX section etc. could be mains pick-up from the transformer/power supply.

 

[J. PUPSTER]

I just bought a QRX-9001, fully restored, from the QRX Restore. It's a beautiful piece of equipment and I'm in love! But it's doing something a little strange.

When I power it up, there a strange flutter/buzz that's mainly coming from the right front speaker. No changing dial positions or inputs make any difference. Even changing speakers to the B outputs didn't change anything. What does affect it is the 4 channel selector buttons. It's not as noticable in CD-4/discrete and very noticeable in SQ. QS is kind of in between.

After playing around with things and emailing with owner Justin, we've both determined it's likely some kind of interference. (I've had it for a month or so and it's only developed in the past week or so, even though nothing has changed around my setup.) I unplugged EVERYTHING nearby; TV, TiVo, Oppo player, phone, lamp, clock, modem. I even moved the receiver over about a foot. Nothing changes.

The only thing I accidentally found was that if I hold my hand in the middle of the left side wooden panel, (not toward the back or front,) it stops.

Does anyone have any thoughts as to 1) what could be causing this and 2) what I can do to stop it? I can't stand next to it and hold my hand near the panel when I want to listen.

Edit. I guess the file is too big to attach. So here is a link if you'd like to hear it.

https://drive.google.com/file/d/1k8Zs7DQwE9_Cxrpq1Abvk1hT9m-MZd4V/view?usp=drivesdk

Try setting the Google Drive link to All access, and get a new link.

I had something similar happen to my QRX-8001 and believe it was cable interference when they were bunched up too close together with power cables. Once I rearrange some cabling it went away.

 

[gvl_guy]

I tried getting your audio file. First odd thing is google drive asked me to sign in. Then it said I need permission to access that file. Then I clicked on "request permission." It said a request has been sent, presumably to you.

I use Dropbox myself, but have accessed many others google drive's for sharing files. I've never run into this before. Hmmm...

Try it now. I turned on "link sharing"

 

[J. PUPSTER]

Try it now. I turned on "link sharing"

Yes the link is good now.

That noise has a very strange repeating blip (oscillation?) to it, not what I had. Mine was more like a fuzzy/crackly constant hum, but would increase as my hand neared the cabling.

 

[gvl_guy]

Yes the link is good now.

That noise has a very strange repeating blip (oscillation?) to it, not what I had. Mine was more like a fuzzy/crackly constant hum, but would increase as my hand neared the cabling.

Mine does exactly the opposite. As I bring my hand close to the center left panel it decreases. But it's very odd since I pulled the power on pretty much everything in the area

 

[J. PUPSTER]

Mine does exactly the opposite. As I bring my hand close to the center left panel it decreases. But it's very odd since I pulled the power on pretty much everything in the area

Maybe try moving the gear temporarily to another part of the house and see what happens; shipping back to qrxrestore can be a real hassle.

 

[Sonik Wiz]

I just bought a QRX-9001, fully restored, from the QRX Restore. It's a beautiful piece of equipment and I'm in love! But it's doing something a little strange.

When I power it up, there a strange flutter/buzz that's mainly coming from the right front speaker. No changing dial positions or inputs make any difference. Even changing speakers to the B outputs didn't change anything. What does affect it is the 4 channel selector buttons. It's not as noticable in CD-4/discrete and very noticeable in SQ. QS is kind of in between.

After playing around with things and emailing with owner Justin, we've both determined it's likely some kind of interference. (I've had it for a month or so and it's only developed in the past week or so, even though nothing has changed around my setup.) I unplugged EVERYTHING nearby; TV, TiVo, Oppo player, phone, lamp, clock, modem. I even moved the receiver over about a foot. Nothing changes.

The only thing I accidentally found was that if I hold my hand in the middle of the left side wooden panel, (not toward the back or front,) it stops.

Does anyone have any thoughts as to 1) what could be causing this and 2) what I can do to stop it? I can't stand next to it and hold my hand near the panel when I want to listen.

Edit. I guess the file is too big to attach. So here is a link if you'd like to hear it.

https://drive.google.com/file/d/1k8Zs7DQwE9_Cxrpq1Abvk1hT9m-MZd4V/view?usp=drivesdk

This is what I think it is:
https://en.wikipedia.org/wiki/Motorboating_(electronics)
Now what causes it more specifically in your Sansui I can't say. Got some sharper folks than me here, maybe someone else can weigh in.

 

[Doug G.]

Poor solder connections can cause it, especially ground connections or, you can try cutting out a cardboard hand and pasting it to the left side center of your 9001.

Doug

 

[gvl_guy]

Poor solder connections can cause it, especially ground connections or, you can try cutting out a cardboard hand and pasting it to the left side center of your 9001.

Doug

Don't think I haven't thought of the hand. Lol.

 

[Doug G.]

Hilarious! Seriously, though, I have always been impressed with Sansui equipment. In 1976, my then wife and I went to the Twin Cities to see Queen and we had a bit of time to kill so we stopped to see my brother and his roommate. His roommate had a Sansui monster system, with the top models of the day, mounted in a rack with ESS Heil speakers.

THAT was impressive!

We almost wanted to stay and listen to his system instead of going to see Queen...

No, I'm lying in that sentence...

Doug

 

[MidiMagic]

Sounds like an electrolytic capacitor breaking down.

 

[1963Christopher]

As an individual who owns some vintage Sansui audio equipment (both quad (QRX-3500) and not (8080)) and looked into having QRX Restore do some work for me in the past, I’d say send it back to them on their dime, have them fix it on their dime, and have them ship it back you on their dime. The ‘recap/restore’ cost of a 9001 is $1400, and that’s with you shipping it to and fro. God knows what you paid for a “restored“ unit from them.

 

[par4ken]

Sounds like a problem caused (or not corrected) by the restorer. Vintage audio can be finicky at times. It might be something as simple as a missing ground, or possibly a couple of components shorting together altering the amplifiers feedback path. I would definitely contact QRX restore, if that's where you got it from.

 

[gvl_guy]

As an individual who owns some vintage Sansui audio equipment (both quad (QRX-3500) and not (8080)) and looked into having QRX Restore do some work for me in the past, I’d say send it back to them on their dime, have them fix it on their dime, and have them ship it back you on their dime. The ‘recap/restore’ cost of a 9001 is $1400, and that’s with you shipping it to and fro. God knows what you paid for a “restored“ unit from them.

With COVID, we weren't going on any vacations so the money budgeted for that went to my listening pleasure.

 

[gvl_guy]

I just bought a QRX-9001, fully restored, from the QRX Restore. It's a beautiful piece of equipment and I'm in love! But it's doing something a little strange.

When I power it up, there a strange flutter/buzz that's mainly coming from the right front speaker. No changing dial positions or inputs make any difference. Even changing speakers to the B outputs didn't change anything. What does affect it is the 4 channel selector buttons. It's not as noticable in CD-4/discrete and very noticeable in SQ. QS is kind of in between.

After playing around with things and emailing with owner Justin, we've both determined it's likely some kind of interference. (I've had it for a month or so and it's only developed in the past week or so, even though nothing has changed around my setup.) I unplugged EVERYTHING nearby; TV, TiVo, Oppo player, phone, lamp, clock, modem. I even moved the receiver over about a foot. Nothing changes.

The only thing I accidentally found was that if I hold my hand in the middle of the left side wooden panel, (not toward the back or front,) it stops.

Does anyone have any thoughts as to 1) what could be causing this and 2) what I can do to stop it? I can't stand next to it and hold my hand near the panel when I want to listen.

Edit. I guess the file is too big to attach. So here is a link if you'd like to hear it.

https://drive.google.com/file/d/1k8Zs7DQwE9_Cxrpq1Abvk1hT9m-MZd4V/view?usp=drivesdk

An update on my situation. I tried again and unplugged everything. Still there. Sometimes louder than others. There are no wires in the wall near there that I know of, so it's likely not that.

I dismantled the entire setup and moved the receiver to another room and.......quiet as a mouse. So, it's something near it, but what? I have no idea.

Someone in one of the Facebook groups suggested grounding the unit from the phono connection to the screw in a wall outlet. That's next on my list. If that doesn't work, I'll need to find something that mimics my hand near the left panel. Moving it to another place in the room isn't an option, unfortunately.

 

[J. PUPSTER]

An update on my situation. I tried again and unplugged everything. Still there. Sometimes louder than others. There are no wires in the wall near there that I know of, so it's likely not that.

I dismantled the entire setup and moved the receiver to another room and.......quiet as a mouse. So, it's something near it, but what? I have no idea.

Someone in one of the Facebook groups suggested grounding the unit from the phono connection to the screw in a wall outlet. That's next on my list. If that doesn't work, I'll need to find something that mimics my hand near the left panel. Moving it to another place in the room isn't an option, unfortunately.

I’m wondering how old your house is?

Is the location of the Sansui near a wall?

If you put it back to that location; maybe try several bottles of water set between the unit and the wall. That’s only a test to see if it blocks the interference. Maybe some electrical grounding issue in that location of your house?

Could be wiring in the walls you’re unaware of.
There are also inexpensive electrical wiring wall scanners you can buy.

Just throwing out ideas to keep some attention on your problem that others may pick up on.

 

[gvl_guy]

Any idea is worth a try and, at this point I don't consider anything too crazy.

The house is only 4 years old and we kinda watched it being built. I don't think there's anything behind that wall that should be causing it. But who knows?

 

[J. PUPSTER]

Any idea is worth a try and, at this point I don't consider anything too crazy.

The house is only 4 years old and we kinda watched it being built. I don't think there's anything behind that wall that should be causing it. But who knows?

Yeah, I was anal enough that when they were building my house about 16 years ago (damn, been that long now!) that I took digital photos of the wiring in the walls of most rooms before they put up the wallboard.

How about just outside the house, any large equipment like A/C units etc.?

And what about any adjacent rooms?

The interference must be coming from somewhere.