Old receiver - high DC offset - no manual/schematic - bias test point & voltage?

[62vauxhall]

I believe so. There is just one large filter cap, and there are 47 volts across it's terminals.

 

[laatsch55]

What are the terminals to ground?

 

[62vauxhall]

That single large cap? It's a one section so only two terminals and neg. is to ground.

 

[laatsch55]

Do the wires to the large cap come from the BR?

 

[62vauxhall]

I can see only one wire going directly from the rectifier to that cap which is to it's pos. terminal.

T

The 20-ish gauge red one that the wood skewer is "pointing" to. There are only two diodes. Is this still referred to as bridge rectifier?

 

[62vauxhall]

It lives

I got it working on AUX and TUNER but discovered it had a dead channel on PHONO. There were five electrolytic capacitors and two pairs of 2SC644's that I replaced and it seems one of capacitor's legs formed a bridge to another pad on the PC board. Solder maintained the bridge on one side but not the other. Easy fix once I knew what the problem was.

The receiver sounded OK on AUX and TUNER but PHONO sounded like crap so that's why I did wholesale replacement of the pre-amp - there was not really a lot on there. I am actually surprised that it sounds as good as it does. Am listening to it now through the $2 Boston Acoustics A70's I just re-foamed.

Supposedly made by what would later become Rotel but I think it's got an old Sansui or HK vibe to it. It's not as pretty as a Sony STR6045 I have but sounds like it has about the same amount of power - 18WPC.

If it is of 1968 vintage, it's the oldest SS piece I have.

 

[Elite-ist]

Good work there, Gary. Some of the looks of your receiver reminds me of my Kenwood KA-2000 from circa 1973.

Nando.

 

[grapplesaw]

Nice job Gary. No wonder you don’t get any sleep

 

[62vauxhall]

Nice job Gary. No wonder you don’t get any sleep

Hey, it's a long weekend and I got two out of three days off. Slept in to nearly 7AM this morning.

 

[Northwinds]

Cool looking receiver!

I have an old ass one I would like to see work again, how many of you have seen this Sansui TR-707A before? It's their first solid state receiver. Just makes weird noise in one channel and the other is silent

 

[Gepetto]

Cool looking receiver!

I have an old ass one I would like to see work again, how many of you have seen this Sansui TR-707A before? It's their first solid state receiver. Just makes weird noise in one channel and the other is silent

Capacitor coupled output to the loudspeakers...

 

[Northwinds]

Is that good or bad Joe? I had a Pioneer SX-626 that was cap coupled though I have no clue what that means

Also, what are the 3 little transformers for?

 

[orange]

IIRC THUMP CONTROL

Keeps the nasty pops from yer speaks.