HOPEFULLY FOUND 1961ish Curtis Mathes

[nightrider]

Hi all,
I am looking for a non bicycle unicorn. In need of a power transformer for a Curtis Mathes 32B receiver amp chassis. Must be in working condition. Must ring at 10 or above when tested.
Thanks for looking,
Johnny

 

[bobcycles]

Vintage Curtis Mathes Stereo console---late 1950s | Sell - Trade: Everything Else

Estate find. Vintage Curtis Mathes console Tube powered with large speakers... Radio and turn table. Untested (cord was cut) I guess these were pretty state of the art back in the day and made in Texas! There is a detailed background about the company on line...

thecabe.com

 

[nightrider]

Vintage Curtis Mathes Stereo console---late 1950s | Sell - Trade: Everything Else

Estate find. Vintage Curtis Mathes console Tube powered with large speakers... Radio and turn table. Untested (cord was cut) I guess these were pretty state of the art back in the day and made in Texas! There is a detailed background about the company on line...

thecabe.com

Mine is in the shop, so I can't post a picture. If it looks like the one Bob posted, that's the one. Key feature is "the eye" tuning tube ( round thing in the middle of the stations) in the center.
Thanks, Johnny

 

[bloo]

Do you have any service information you can post like a schematic diagram? Must it be an original exact replacement? Depending on the windings it has, something off-the-shelf from Hammond or a similar manufacturer might work... or not.

There is a company called Heyboer who will make you a new identical replacement if you send them the old one to unwind.

Possible places to ask include antiqueradios.com, who have a classified section. Videokarma.org is another possibility although I don't know if they allow ads, you would have to look. It is primarily a TV site, but Curtis Mathes was known primarily as a manufacturer of television sets, so that brand gets some traffic now and then.

 

[nightrider]

Do you have any service information you can post like a schematic diagram? Must it be an original exact replacement? Depending on the windings it has, something off-the-shelf from Hammond or a similar manufacturer might work... or not.

There is a company called Heyboer who will make you a new identical replacement if you send them the old one to unwind.

Possible places to ask include antiqueradios.com, who have a classified section. Videokarma.org is another possibility although I don't know if they allow ads, you would have to look. It is primarily a TV site, but Curtis Mathes was known primarily as a manufacturer of television sets, so that brand gets some traffic now and then.

I have a very promising lead thanks to @bobcycles . Talked to Hammond, it would have to be custom ($650). And not 100% sure about it working. I have the schematic, but CM was very secretive about their products. There are a few unknowns in their drawings.

 

[bobsbikes]

you have got the wrong guy here try bobscycles sorry

 

[bloo]

I have the schematic, but CM was very secretive about their products. There are a few unknowns in their drawings.

It might still be possible to figure it out, and if your lead doesn't work out it is likely something off the shelf could bring it back to life. I'm not sure how much ring testing matters. Power transformers for tube based audio are not the sort of black magic that HV transformers are in TV sets for instance. Only one shorted turn in the sort of power transformer used in an audio amplifier will cause the transformer to draw too much current and either blow fuses or smoke. It is pretty hard to miss. Good luck on your lead and I hope you find what you are looking for. If not maybe post the schematic and I will see if I can come up with any ideas.

 

[Schwinny]

Just saw this but I know its a couple months old.
First, Tube electronics have been my main hobby since 1975 and I used to run a repair business in Seattle on the side of my actual job so.....
I've put all that behind me now but I still dabble. Check out Resoundingamplification on FB.
Anyway,
You don't need an exact replacement PT for a standard consumer level Combination chassis. Curtis Mathes was decent stuff but nothing special in its time other than touting how they were a small American Electronics Company (underdogs). They were manufacturing in Texas and Georgia, this is where most CM is found.
All you need to worry about is the tap levels and how many. Voltages can be lowered but not so easily raised so with 6BQ5 outputs the HV tap needs to be 360-400v.
Mono or Stereo?
Just find a Tube amp PT that fits the footprint and has enough taps.
I may have one or two left over around here.
If you give me the numbers off the PT I can look up the date, maker and maybe the specs.
There is always the SAMS folders to look through for info also.
Ebay is filthy with PT's that would work fine.

 

[nightrider]

Just saw this but I know its a couple months old.
First, Tube electronics have been my main hobby since 1975 and I used to run a repair business in Seattle on the side of my actual job so.....
I've put all that behind me now but I still dabble. Check out Resoundingamplification on FB.
Anyway,
You don't need an exact replacement PT for a standard consumer level Combination chassis. Curtis Mathes was decent stuff but nothing special in its time other than touting how they were a small American Electronics Company (underdogs). They were manufacturing in Texas and Georgia, this is where most CM is found.
All you need to worry about is the tap levels and how many. Voltages can be lowered but not so easily raised so with 6BQ5 outputs the HV tap needs to be 360-400v.
Mono or Stereo?
Just find a Tube amp PT that fits the footprint and has enough taps.
I may have one or two left over around here.
If you give me the numbers off the PT I can look up the date, maker and maybe the specs.
There is always the SAMS folders to look through for info also.
Ebay is filthy with PT's that would work fine.

Thanks for the reply. I just received an og unit from bobscycles, hope it checks out.
Unfortunately, I know nothing about electronics. Going by what my guy says. Mine has got so hot over the years it's not working correctly. Guy says it rings around 6, and should be around 14+, or something. He won't restore the caps without a good PT. He won't modify it either, says it's a "hot chassey" and can't modify due to liability issues. Also sent schematics to engineers, they say there isn't enough information regarding the output levels.
Thank you for the response. If this PT doesn't work out, I may message you.
Johnny

 

[Schwinny]

Thanks for the reply. I just received an og unit from bobscycles, hope it checks out.
Unfortunately, I know nothing about electronics. Going by what my guy says. Mine has got so hot over the years it's not working correctly. Guy says it rings around 6, and should be around 14+, or something. He won't restore the caps without a good PT. He won't modify it either, says it's a "hot chassey" and can't modify due to liability issues. Also sent schematics to engineers, they say there isn't enough information regarding the output levels.
Thank you for the response. If this PT doesn't work out, I may message you.
Johnny

Uh, I'd step carefully with your "tech" if he thinks that is a hot chassis. It is not. At least if we are talking about the console I think we are talking about. I've never seen a hot chassis CM, but maybe.....
Hot chassis electronics were the bottom level of all tube electronics. Usually table top radios.
Maybe he was saying that it is now hot. Meaning a few caps need replaced.
Hot chassis electronics do not have Power Transformers. They run directly off the wall and split the 120v between the tubes. All of the vacuum tubes on the chassis' 1st number (ie: "12"ax7) will all add up to 120.
Or....
It could accidentally be hot because of a bad capacitor can or screen bypass cap.
Actually.... a bad cap can being grounded out could mess up the PT and create a hot chassis situation.
All repair and maintenance on tube amplifiers should include replacing the Cap Can, by now, this many years later, they are all out of wack, all of them. And this could cause a PT grounding situation thus diverting current to the chassis making it "hot."
This is why people that know, will tell you not to energize old tube electronics until they have been gone through and checked out. The result could be popped PT taps or blown OPT's.
Perhaps if the cap can was replaced first that would solve the issue.....
If the PT is simply overheating but not runaway, it is not the PT's fault. There is something down line causing a high current load (perhaps grounding)