Meters on a Sony SQR 6650

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ehtoo

New member
Joined
Sep 11, 2015
Messages
9
Location
Toronto Ontario CANADA
Once again, new to both having a receiver and definitely new to Quad receivers. I recently stumbled upon and purchased a Sony SQR 6650. Replaced all the lamp fuses with LED's and now of course notice not all the meter needles are moving. What do you guys do to free them up? One thing I've read is the heat from the old lamps tended to distort the film used which may be the cause for non-functioning meters. I'm kind of hoping it's 43 years of gunk.

Of course, functioning meters won't get in the way of me enjoying the Sony but, the OCD part of my psyche likes the idea of them working properly.
 
I don't have experience with this particular amp, but I'll give it a shot. Are you getting audio from all four channels? You don't say which channel meters are moving and which are not. It is possible the meter film is warped, but unlikely, I'm afraid. If that were the case I think you would still see slight movement of the needles trying to move. And I think you would have noticed that extreme deformity when you were changing the lamps. (Are you sure you did not damage the casing when you did that?)

Are you testing this with a discrete 4-channel source? If you don't have a 4 channel source available, try plugging a stereo source - CD player, etc - into the rear channel inputs of a discrete input (4-channel Tape, for example), test for audio pass thru and check for meter movement. Then plug the device into the front channel inputs and repeat the test for the front channels. If you are passing discrete audio through each channel but the meters are not responding, I suspect a problem in the meter circuit. It would seem to be more than a coincidence that it would be either both front or both rear channels meters to go dead as a result of heat warping. If it is just one meter, look for a loose connection or bad solder point somewhere in that meter's circuit. Good luck.
 
Thanks for your response. I'll do what you suggest in regards to the 4-channel meter. I didn't notice any specific warping of the film when I was changing the lamps. Right now, for the 2 channel set, the right front needle is maxed whilst the left is responding to the signal. The tuner signal meter is also maxed (needle to the extreme right) and unresponsive to changes in station tuning.
I'll go through connections etc. when I recap the receiver. I'm trying to source some solder pin vs. glue electrolytic caps - specifically the two 25V 3300uf. Right now the closest I've come is through Michael Percy out of Brooklin ME who has some Nichicon 35V 4700uf. (price good too)
If you can recommend other sources for good audio grade caps, please by all means, make a suggestion.
 
With the meters unsoldered from the unit test them with a ohm meter. If they move they are fine. If they don't then they are bad. If they seem to be stuck at full range they may have a broken "clock spring"...

ByTheWay...Do they return to "0" when the power is turned off?
 
I was going to ask that same question concerning if the meters returned to hard left when the amp is powered off. When you said the meters didn't move I thought you meant they remain hard left. Pegging hard right is different story and I suspect Bushmaster may be correct about that meter's dock spring. Just to be clear, is this amp hooked up to speakers and are you getting a clean signal out of the front right channel? Are the rear meters working correctly when a signal is going through them?

The signal strength meter is a different problem because that is not measuring volume, it is indicating the strength of a radio signal. You do have an FM antenna hooked up and you are receiving stations, correct? Hard right on that meter may be the 'no signal' position for that meter if it is a 'center tuning' type, but if you are getting stations strongly then there is a problem in that circuit. As far as suppliers for caps, I'll let some other members that have done more re-capping jobs than I weigh in on that.
 
First thanks to both Wagonmaster and Bushmaster for your input. My meter situation is not quite as bad as I thought initially. Front left VU meter is stuck a very near the max reading and doesn't return to zero when the receiver is turned off. Front right good but stays at the middle position when off. Both rear respond when set in Mix & SQ (4ch not responding of course as broadcast signal is 2 channel) and return to zero when off. The tuner signal meter is stuck at one on and off. Having said this, I've a simple copper wire for now. Sensitivity is very good and I'm receiving stations very well in spite of the wire. So good that I'm going to buy an FM antenna to make it better so we'll see if that meter will budge. When I open the thing up again, I'll Ohm out the meters.

Question: if the clock spring is "broken" is there a remedy?

This is my first Quad so right now I'm just using headphones which means front only.
 
If the clock springs are broken the only remedy is to replace the whole meter.

Cheap FM antenna: Get some TV "flat [2 conductor] wire and make a "T" antenna. The main lead from the receiver can be any length and the top of the "T" should be at least 5 to 9 feet. Solder the leads in a continuous loop from the receiver"s left screw back to the receiver's right screw.
 
... One thing I've read is the heat from the old lamps tended to distort the film used which may be the cause for non-functioning meters. I'm kind of hoping it's 43 years of gunk.

Of course, functioning meters won't get in the way of me enjoying the Sony but, the OCD part of my psyche likes the idea of them working properly.


I also suffer from a bit of OCD, so I can relate.
The meter scales are made of a thin hard plastic that Sony apparently silkscreened to lay down the image of the scale. Being that these scales are made of "unobtanium", I actually purchased three of the 6650s off of Ebay, just trying to get one good pair of VU meter scales that were not warped...
In the process, I discovered that Sony manufactured these faces in two colors! My latest purchase came with turquoise colored VU & radio scales rather than the standard green.

Removal:
There is a strip of double-sided tape that Sony used to attach the top of the VU meter body to the inner metal face plate, so after removing the lamp housing, I reached down under the plastic body of the scales and gently pulled back toward the back of the radio (grimacing as I listened to the tape tearing apart). Once free of it's mounting, I found the front side of the meters had a rectangular clear dust cover taped over the needles & plastic scales, which in turn, was held in place by thin strips of tape. With this dust cover off, I was then able to slide a THIN Exacto knife blade in between the two VU needles and down behind the plastic scale to cut through the adhesive used to glue the scales to the front side of the VU meter body. The dust covers actually fit into the openings in the metal face plate, so that ensured the meters were always aligned properly when taped to the back of the face plate.

And yes, these scales warp from the heat of the fuse lamps (my latest radio came with LED lamps, by the way), and I'm sure the dust covers only aggravated the heat build up. They warp, just like a vinyl album. I've tried searching to see if there's a safe, reliable method to heat them up and flatten them out but so far, have come up short. I have no idea what kind of plastic was used and even if I did, whether there would be any information on what would be considered a safe temperature to use (in either an oven or possibly, a container of hot water) during the flattemimg process.

If anyone has experience with that, I would love to hear from you!!
 
I also suffer from a bit of OCD, so I can relate.
The meter scales are made of a thin hard plastic that Sony apparently silkscreened to lay down the image of the scale. Being that these scales are made of "unobtanium", I actually purchased three of the 6650s off of Ebay, just trying to get one good pair of VU meter scales that were not warped...
In the process, I discovered that Sony manufactured these faces in two colors! My latest purchase came with turquoise colored VU & radio scales rather than the standard green.

Removal:
There is a strip of double-sided tape that Sony used to attach the top of the VU meter body to the inner metal face plate, so after removing the lamp housing, I reached down under the plastic body of the scales and gently pulled back toward the back of the radio (grimacing as I listened to the tape tearing apart). Once free of it's mounting, I found the front side of the meters had a rectangular clear dust cover taped over the needles & plastic scales, which in turn, was held in place by thin strips of tape. With this dust cover off, I was then able to slide a THIN Exacto knife blade in between the two VU needles and down behind the plastic scale to cut through the adhesive used to glue the scales to the front side of the VU meter body. The dust covers actually fit into the openings in the metal face plate, so that ensured the meters were always aligned properly when taped to the back of the face plate.

And yes, these scales warp from the heat of the fuse lamps (my latest radio came with LED lamps, by the way), and I'm sure the dust covers only aggravated the heat build up. They warp, just like a vinyl album. I've tried searching to see if there's a safe, reliable method to heat them up and flatten them out but so far, have come up short. I have no idea what kind of plastic was used and even if I did, whether there would be any information on what would be considered a safe temperature to use (in either an oven or possibly, a container of hot water) during the flattemimg process.

If anyone has experience with that, I would love to hear from you!!

I'm wondering if sandwiching between two pieces of glass, then gently heating with a hair dryer would work? Thanks for the above. When I get around to doing mine I'll follow your method.
 
I'm wondering if sandwiching between two pieces of glass, then gently heating with a hair dryer would work? Thanks for the above. When I get around to doing mine I'll follow your method.
I'm wondering if sandwiching between two pieces of glass, then gently heating with a hair dryer would work? Thanks for the above. When I get around to doing mine I'll follow your method.

Taking a hair dryer - or heat gun for that matter - to the scales, even if they are sandwiched between glass leaves me concerned about hot spots. I'm not discounting the idea though. There's at least one video of a heat gun being used for repairs on YouTube.

Flattening the scales is more of a "Plan-C" for me at the moment ("Plan-A" being the purchase of additional 6650s in hopes of hitting the jackpot).
Why?
Well, let's just say it's not going to bode well for me when Mrs. G-Whiz finds out what I've been up to in her kitchen!

If I'm going to attempt flattening the scales, first I'll need to purchase one of those new-fangled IR laser thermometers to get a temperature reading of the inside of the meter's dust cover after I've had the lamps heating it up for a good hour or two. Once I get that magic number, I'll want to toss the glass sheets & rubber bands(for lack of a better idea for applying a constant compression pressure as the glass sheets get closer and closer together) into Mrs. G's crockpot full of water. I need to make sure her crock pot comes with a continuously adjustable temperature control so I can bring it all up to the same temperature as the reading on the inside the radio's VU meters.

Anyway, I'll want to glue spacers in the corners of one of the sheets of glass so I can't overly squish the plastic and end up with a flat, oval-shaped piece of useless plastic. I'm thinking I'll also want to coat the inside surfaces of these glass sheets with some kind of silicone grease to reduce the chances of rubbing off the silkscreen, paint, or whatever material Sony used to apply the colors to the scales. (That grease is the part that I think is going to get me in hot water with Mrs. G)

Why would I want to use a hot water bath? Well, I figure It will give me waaaaay more stability and control over the temperature than with a hair dryer or heat gun. After all, the goal is to get the scale to relax without worrying about overheating and turning it into a blob of runny, melted plastic.

It's also going to be easier on my ears than a hair dryer or heat gun... although...
... after Mrs. G-Whiz gets done with me, I may be no better off!! :mad:@:

Once the water and the glass sheets are up to temperature, I can pull them out, pop in a scale and then submerge the whole thing back into the hot water bath. The hot water will flood the cavity around the scale, heating up the entire scale, not just the small spots hat are in direct contact with the glass, and allow the entire scale to relax and reshape as the glass forces it back towards its original shape. Those last four words are probably going to be the gotcha in this scenario though. Something tells me that the scale will not return exactly to it's original rectangular dimensions. I'm thinking it could end up being wider across the bottom than at the top because of the cutouts for the VU meters along the top edge of the scale. Cutting and trimming will probably be required just to get them to fit back inside the dust cover.

"Yawn... He's been yammering on and on about "Plan-A" and this no-win "Plan-C". What gives? What's his "Plan-B"???

1200dpi VU Scales Under Construction.jpg


In case you haven't guessed from this screen shot, I'm designing a 1200dpi black mask and want to see if I can find a company that can reproduce it at that resolution and also supply me with transparent green/turquoise sheets of plastic that can be placed on the back side of the mask. The question will be whether or not they can hook me up with sheets that will match the color of the radio scale.

I've tried the laser printers at Office Depot and Fed-Ex (formerly Kinko's) and they can't do non-transparent blacks on clear plastic which requires at least 3 layers of the mask just to block out the light. They also can't seem to go any finer that 120 or 200 DPI, and finally, I can't get the vibrant colors seen with the original VU scales that you see here on the right. Instead of an intense, deep green, the color is all muddy:
2016-03-02_00.51.09.jpg

Did I mention I suffer from a little bit of OCD?? :p
 
I'm wondering if sandwiching between two pieces of glass, then gently heating with a hair dryer would work? Thanks for the above. When I get around to doing mine I'll follow your method.

Sit tight and don't tear into your VU meters just yet.
I responded yesterday with a couple pics of what I've been up to but whoever has to do the review/release of my post hasn't got around to it yet.
I'm not ignoring you, I promise!
 
There was and might still be a company that makes repro radio dials, they were thin lexan, that might work.
 
There was and might still be a company that makes repro radio dials, they were thin lexan, that might work.
Good idea! Thanks!!
I purchased a glass reproduction scale for my 1939 AM/SW Philco radio from Radio Daze maybe 6 or 8 years ago, but they and the RadiolaGuy always seem to be catering to the old tube radio restoration crowd. I never considered that they might be able to tackle this task. The tricky part (besides reproducing the 1200 dpi resolution) will be in matching the green/turquoise tinting and luminosity of the radio scale.
I just left a message through the Radio Daze web site. Hopefully they are up to the task.
 
Since my last post, I was sidelined by a medical issue which has since been resolved for the most part (feeling a little run down nowadays, but better than I was).

I contacted Radio Daze, explained the scenario, and after they overlooked my initial inquiry, I finally got the following reply...

Clyde:

Thank you for your inquiry.

Sorry for delayed response. We typically receive 25-35 inquiries a day. We may have missed yours.

It would likely be very difficult to match shade and intensity of the new production meter scales to existing, aged dials. Our approach typically has been in sets with multiple visual pieces to replace them all so that they do match. Obviously that approach may be too radical for the SQR-6650.

If you have a scale you can send to us, we can take a look and give a more informed opinion - certainly would be returned.


Best regards,
John

Radio Daze LLC
c/o John - Graphics
3870 Rush Mendon Road
Mendon NY 14506


I whipped out my trusty 30 watt soldering iron & pulled one pair of VU meters and the tuner signal strength meter from my "parts" radio. As you can see below, the nylon(?) plastic bodies are scorched all the way through with a deep "Coppertone tan" (am I showing my age?).
(The spots on either side of the meters are where the scales were glued to the bodies)
Since the scales are illuminated by the light passing through the scorched nylon, the meters will also have to be sent with the VU, radio dial, and truner strength scales, in order for these guys to get a half way reasonable color & intensity reading. Half way, since the amount of heat build up & scorching seems to have varied from one radio to the next - and not all scales ended up warped, as you can see here.
2016-04-14_22.59.19.jpg

My other avenue of attack - the re-drawing of the VU and tuner strength scale masks at 1200 DPI is complete - at least to the point of being ready to talk to someone who has an offset printer.
Taking time off from work between now and November to show a local business what I've got is going to be a problem - something I'll only have time (at least for now) to pursue during my lunch hour.
 
The camera lied in this photo. I think the camera's automatic exposure control overexposed the shot because the scene was so dark. To the eye, the radio scale is actually a lighter shade of green... not the turquoise seen here. The warped VU meter still looks green simply because it is not as bright as the radio scale.
For this picture, I sat a LED light on top of the radio. In front of that, I put a scorched VU meter body for the light to shine through. In front of those I held up a white sheet of paper along with 2 blue and 2 green tinted sheets of plastic (gels, as they're called for stage lighting).
The turquoise glow at the very top of the photo is light shining directly on the back of the paper from the LED light.
Below that, the darker green(ish) glow is from the discolored light that's passing through the scorched VU meter body.
Given that the radio scale is illuminated from behind, directly by the fuse lamps while the light has to pass through the VU meter housings before reaching the VU scales, the radio scale lamps will have to be dimmed if they are going to match the lower luminosity of the VU and radio signal strength meters.
If my OCD was totally out of control, the tint and luminosity would have to perfectly match, but since it isn't, well, "in the ballpark" is good enough for me if that's all it takes to get the needles merrily swinging away again.
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A local printer said they had a 1200 dpi printer and I gave it a shot.
Unfortunately,
- Under a magnifying glass, it doesn't look like any better resolution than the 300 dpi printer at the other place
- The black wasn't as dense as the other copier (more light passed through from behind)

They said if this didn't work I could try one of the other local printers to see about printing a film negative (well, actually, a positive). They said that may be the only way to get a truly non-transparent black mask.

Only time will tell.
Stay tuned...
 
Sorry about "going dark".
Management turned on it's employees at the agency where I worked and by late May or early June I realized there was now a target on my back, leaving me with no choice... I had to get out of there before they could destroy my reputation and make it impossible to find work elsewhere. Unfortunately, it was an ordeal that was not resolved until the week before last.
All is good now but there's still a ton of studying to do for my new job, and that doesn't include all the other Summer/Fall projects I had that were forced onto the back burner as well. Projects such as prepping our cars for Winter that obviously now have priorities higher than this project.

By the beginning of June I realized the colored gels by themselves would (could!) not give me the colors I needed to match the radio scale. I needed to further tweak the green gel color and to get that, would require tweaking the light source.

How? Well, I believe I will have to mount tri-color LEDs behind the meters in place of the fuse lamps and individually adjust each of their colors (red/blue/yellow) in order to match the the red/green colors on the radio scale.

It my be Spring or even Summer before I will have the time and energy to return to this project.
As I've said before...
Only time will tell.
 
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