VM 570 Mono/Stereo switching
VM 570 Mono/Stereo switching
Hello everyone and Happy New Year!
Tried to play a stereo record on my VM-570 and realized that it only outputs one channel.
It seems that the repair guy made a mistake in the wiring during the restoration.
The record changer has two slide switches:
- Tuner/Phono (the unit does not come with a tuner).
- Mono/Stereo
They way it works now:
- Tuner/Phono switch to Phono and Mono/Stereo switch to Mono --> record player, only one channel
- Tuner/Phono switch to Phono and Mono/Stereo switch to Stereo, rotary switch (Off, On, Rej) to Off --> audio from AUX input
As Bill very well explained in a previous post ( viewtopic.php?p=23009#p23009 ), when using the external speaker cabinet the M/S switch should be set to Stereo. When using the built-in speakers it should be set to Mono.
How about the Tuner/Phono switch? When it's at the Tuner position, there's no power to the unit (pilot lamp is off).
Will see if I can re-wire the switches based on the schematic, to make them work as they are supposed to...
By the way, as finding the external speaker cabinet would be very hard, would it be possible to use any other external amplified speaker to make it stereo?
cheers,
Andreas
Tried to play a stereo record on my VM-570 and realized that it only outputs one channel.
It seems that the repair guy made a mistake in the wiring during the restoration.
The record changer has two slide switches:
- Tuner/Phono (the unit does not come with a tuner).
- Mono/Stereo
They way it works now:
- Tuner/Phono switch to Phono and Mono/Stereo switch to Mono --> record player, only one channel
- Tuner/Phono switch to Phono and Mono/Stereo switch to Stereo, rotary switch (Off, On, Rej) to Off --> audio from AUX input
As Bill very well explained in a previous post ( viewtopic.php?p=23009#p23009 ), when using the external speaker cabinet the M/S switch should be set to Stereo. When using the built-in speakers it should be set to Mono.
How about the Tuner/Phono switch? When it's at the Tuner position, there's no power to the unit (pilot lamp is off).
Will see if I can re-wire the switches based on the schematic, to make them work as they are supposed to...
By the way, as finding the external speaker cabinet would be very hard, would it be possible to use any other external amplified speaker to make it stereo?
cheers,
Andreas
- TC Chris
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Re: VM 570 Mono/Stereo switching
As to the second channel, yes, any amplified speaker will give you the second channel. But for audio quality, you want the second channel to match the first one in audio characteristics.
All amplifiers will sound different, and to a much greater extent, so will all speakers. Speakers are the weak link in sound reproduction, the point at which it is most difficult to avoid coloring the audio. They are mechanical devices and harder to make perfect.
So my advice would be to choose speakers--the mechanical transducers themselves-- that are similar to the ones in your unit. Try to match in size and enclosure design. Sealed box air suspension) or open-back or bass reflex? You've probably got open-back with large bass speakers and either horn or cone high-frequency devices.
I have a Zenith table radio that is stereo but missing its second speaker. My plan for building a second one is to match the dimensions of the speaker (transducer) and the enclosure.
Chris Campbell
All amplifiers will sound different, and to a much greater extent, so will all speakers. Speakers are the weak link in sound reproduction, the point at which it is most difficult to avoid coloring the audio. They are mechanical devices and harder to make perfect.
So my advice would be to choose speakers--the mechanical transducers themselves-- that are similar to the ones in your unit. Try to match in size and enclosure design. Sealed box air suspension) or open-back or bass reflex? You've probably got open-back with large bass speakers and either horn or cone high-frequency devices.
I have a Zenith table radio that is stereo but missing its second speaker. My plan for building a second one is to match the dimensions of the speaker (transducer) and the enclosure.
Chris Campbell
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Re: VM 570 Mono/Stereo switching
I would hold off rewiring anything until you have had a chance to kibbitz with Bill here on the forum. He has one of those and is intimately familiar with how it works. He also had an issue with that stereo/mono setup on his. It doesn't work like you think it would. Don't quote me on this, nor hold me to it, but I think your unit is working like it should. Good luck....
A good leader is someone who can tell you where to go, and make you look forward to the trip.
Never allow someone who has done nothing to advise you on anything.
Never allow someone who has done nothing to advise you on anything.
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Re: VM 570 Mono/Stereo switching
anpap wrote: ↑Sat Jan 04, 2025 10:17 pm Hello everyone and Happy New Year!
Tried to play a stereo record on my VM-570 and realized that it only outputs one channel. IF YOU HAD THE MONO/STEREO SWITCH IN MONO YOU ARE HEARING BOTH TRACKS, JUST NOT IN STEREO.
It seems that the repair guy made a mistake in the wiring during the restoration. IT IS POSSIBLE THAT HE ERRORED WITH THE WIRING, THAT IS TRICKY WITH THESE UNITS.
The record changer has two slide switches:
- Tuner/Phono (the unit does not come with a tuner).
- Mono/Stereo
They way it works now:
- Tuner/Phono switch to Phono and Mono/Stereo switch to Mono --> record player, only one channel. THAT IS CORRECT, YOU ARE HEARING BOTH TRACKS JUST NOT IN STEREO SEPARATION.
- Tuner/Phono switch to Phono and Mono/Stereo switch to Stereo, rotary switch (Off, On, Rej) to Off --> audio from AUX input. NOT SURE WHAT YOU ARE TRYING TO SAY HERE. IF THE PHONO/TUNER SWITCH IS IN PHONO, MONO/STEREO SWITCH IN STEREO, AND OFF, ON, REJ, SWITCH TURNED OFF THE UNIT SHOULD BE DEAD.
As Bill very well explained in a previous post ( viewtopic.php?p=23009#p23009 ), when using the external speaker cabinet the M/S switch should be set to Stereo. When using the built-in speakers it should be set to Mono.
How about the Tuner/Phono switch? When it's at the Tuner position, there's no power to the unit (pilot lamp is off). THAT IS CORRECT, THE TUNER SWITCH ONLY TURNS OFF THE CHANGER MOTOR AND SWITCHES OVER THE INPUT. (FROM PHONO TO TURNER) INORDER TO GET POWER, EVEN FOR THE TUNER, YOU MUST HAVE THE OFF, ON, REJ, TURNED ON TO TURN ON THE AMP. ALSO REMEMBER THAT THE TUNER INPUT IS MONO ONLY AS THERE IS ONLY ONE RCA INPUT RECEPTACLE ON THE BACK OF THE 570.
Will see if I can re-wire the switches based on the schematic, to make them work as they are supposed to... BEFORE YOU REWIRE ANYTHING PLEASE PROVIDE US/ME WITH PHOTOS OF THE WIRES GOING TO THE MONO/STEREO SWITCH AS WELL AS THE TUNER/PHONO SWITCH. THERE ARE SIX TERMINALS ON THE TUNER/PHONO SWITCH BUT ONLY 3 ARE USED. THERE ARE 3 TERMINALS ON THE MONO/STEREO SWITCH BUT ONLY 2 ARE USED. IT DOES GET CONFUSING TO WHAT GOES WHERE ESPECIALLY IF YOU DID NOT MAKE A DIAGRAM BEFORE YOU REMOVED THE WIRES.
By the way, as finding the external speaker cabinet would be very hard, would it be possible to use any other external amplified speaker to make it stereo?
YES, ANY THING WILL PROBABLY WORK BUT AS CHRIS POINTED OUT IT WOULD NOT PAIR WELL WITH THE MAIN UNIT. THE AUX. SPEAKER/AMP, VM102, HAS AN OPEN BACK, 10" WOOFER AND 4" TWEETER, BOTH ARE CARBONNEAU AND THE AMP IS TRANSFORMER POWERED WITH A EZ81 RECTIFER, 12AX7, 6AU6, AND PP 6BQ5'S.
HERE ARE THE MODELS OF THE AUX. SPEAKER/AMP THAT WOULD MATCH YOUR VM570 FOR SPEAKER AND AMP. THE CABINETS WILL BE THE DIFFERENCE. VM102 IS THE MATCH. VM101, 103, AND 104 WILL BE DIFFERENT CABINETS. THERE IS ONE MORE MODEL THAT WOULD WORK, VM167. VM BUILT THIS M0DEL AS A STAND ALONE MODEL. IT WAS INTENTED TO PAIR WITH ANY LATE MODEL VM RECORD PLAYER THAT WAS CAPABLE OF BECOMING STEREO. IT WAS JUST ONE FURNITURE STYLE BUT CAME IN A FEW FINISHES. I HAVE SEEN A BLONDE ONE AND I HAVE A MAHOGANY ONE. THE AMP IS VERY SIMILAR TO THE MAIN UNIT AMP IN THE VM570 AND HAS A 12" WOOFER AND 4" TWEETER AND BOTH ARE CARBONNEAU.
HERE'S A LIKE THAT SHOWS THE VM167 SPEAKER/AMP. AS YOU CAN SEE IN THE PHOTO THE AMP LOOKS THE SAME. IN THIS UNIT THE WOOFER IS NOT ORIGINAL BUT THE TWEETER IS.
https://reverb.com/item/74589509-voice- ... 9-tube-amp
I HOPE THIS HELPED. BILL
cheers,
Andreas
Re: VM 570 Mono/Stereo switching
Thank you all for the information!
Here are two photos of the switches I took from the bottom of the record changer, without removing it.
The red-white-black wires on the Mono/Stereo switch seem to be the ones coming from the cartridge.
Will try to trace each wire and post more details soon.
cheers,
Andreas
Here are two photos of the switches I took from the bottom of the record changer, without removing it.
The red-white-black wires on the Mono/Stereo switch seem to be the ones coming from the cartridge.
Will try to trace each wire and post more details soon.
cheers,
Andreas
Re: VM 570 Mono/Stereo switching
Here's a draft diagram of what I managed to see.
Will try again tomorrow with daylight...
Will try again tomorrow with daylight...
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Re: VM 570 Mono/Stereo switching
I am sorry to tell you Andreas, but that is not wired correctly. The tuner/phono switch is definitely wrong and the photo of the mono-stereo switch is to congested to see what he did. Your diagrams are good, just not right. Since my camera and iPad are both old school they no longer work with the forum so I can not provide a photo, but I can send you an email because that seems to still work with my computer. When you get a chance try and take a few more photos of how it is wired and then I will explain how it should be wired.
Bill
Bill
Re: VM 570 Mono/Stereo switching
Hi Bill,
Thanks for the info!
Doesn't surprise me that the wiring is not correct.
Took some more photos, but they still may not be clear enough. Uploaded them here:
https://drive.google.com/drive/folders/ ... sp=sharing
I may have to remove the record changer to get a clear view...
The way I suppose it should be wired is that the three wires from the cartridge (the part in the red rectangle in the attached image?) go to the Mono/Stereo switch. Suppose Black is GND, and white and red are Left and Right.
In the Mono position, L and R channels are combined and connected to the amplifier.
By the way, are they just connected together? Would it be better to use a simple circuit like this? https://content.instructables.com/FWE/X ... o0MDowMi4w
In the Stereo position, one channel goes to the amplifier and the other goes to the external speaker connector (is it the two-pin connector at the side of the amplifier)?
Is my understanding correct?
cheers,
Andreas
Thanks for the info!
Doesn't surprise me that the wiring is not correct.
Took some more photos, but they still may not be clear enough. Uploaded them here:
https://drive.google.com/drive/folders/ ... sp=sharing
I may have to remove the record changer to get a clear view...
The way I suppose it should be wired is that the three wires from the cartridge (the part in the red rectangle in the attached image?) go to the Mono/Stereo switch. Suppose Black is GND, and white and red are Left and Right.
In the Mono position, L and R channels are combined and connected to the amplifier.
By the way, are they just connected together? Would it be better to use a simple circuit like this? https://content.instructables.com/FWE/X ... o0MDowMi4w
In the Stereo position, one channel goes to the amplifier and the other goes to the external speaker connector (is it the two-pin connector at the side of the amplifier)?
Is my understanding correct?
cheers,
Andreas
- William
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Re: VM 570 Mono/Stereo switching
Hey Andreas. What ever your guy did he made a mess out of it. Of course, maybe someone else was there first and he only followed what they left behind. Anyway, in order for it to work as VM had intended you will need to reconfigure all of it. Please give me a few days and I will email you a diagram of how it should be wired at all points. You will need to remove the changer to make the correct changes and you will need soldering tools. Stay tuned.
Bill
Bill
Re: VM 570 Mono/Stereo switching
Hi Bill,
No hurry.
Meanwhile I will go through the documentation to see how to remove the record changer.
Doesn't seem to be hard..
- Andreas
No hurry.
Meanwhile I will go through the documentation to see how to remove the record changer.
Doesn't seem to be hard..
- Andreas
- William
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Re: VM 570 Mono/Stereo switching
Hi Andreas,
It is not hard, and since it is wired all wrong I will walk you through putting the wires where they belong but I will probably need a few more photos once the changer is out. Once I see those, this is to make sure that wiring is not messed up, I will be able be able to walk you through it.
Bill
It is not hard, and since it is wired all wrong I will walk you through putting the wires where they belong but I will probably need a few more photos once the changer is out. Once I see those, this is to make sure that wiring is not messed up, I will be able be able to walk you through it.
Bill
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