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Sansui 661 Recap/Parts List Thread

Finally getting to the point of placing my order (have had lots of other things going on) and while giving everything a once over I realized I forgot to ask what would be suitable replacements for the variable resistors on the diver board. VR 1 & 2 are 5k ohm and VR 3 & 4 are 1k ohm. I tried looking something up on mouser, but there's stuff about power ratings and I really don't know what I'm doing when it comes to sourcing most of these parts.
 
Maybe the more experienced can correct me here, but I would use film caps for all those electros up to 3.3uF. Understand that some even go up to 4.7uF.
Perhaps WIMA or equivalent?
Cheers,
Robert.
 
You could, and yes, even up to 4.7µF, just make sure the voltage rating of the replacements is the same or more, and that there is the physical space to mount the larger film capacitors.

Note: they are a lot more expensive than their electrolytic equivalents.
 
Thanks John. I replaced all electros upto 3.3uF on an AU217 (taking care of voltage and available space) and there is a noticeable audio improvement.
However, since the 217 is just one model above BOTL, I'll avoid any "over description" of the audio improvement.

Cheers,
Robert.
 
Finally getting around to starting this recap. Parts are in and got some free time. Looking closer at the power supply I noticed that the original filter caps seem to have three legs. I gingerly took one out and it's got a negative, positive, and a leg that the markings on the side tell me are the "NC" leg. Looking at the position of that leg on the board I found that it doesn't actually go anywhere. It's not connected to any trace or ground and seems to only have it's own hole and pad out in no man's land. The component side of the board has the little capacitor symbol between the other two legs.

Without actually understanding the circuitry, and with the above observations, I'm about 97% sure that I can just put my normal old two leg capacitor in between the two holes marked as such and leave that mysterious third hole alone. Would that be correct? And what is that third leg actually for?
 
Correct, NC means No Connection - and the leg was just for support (the number of times this comes up :rolleyes: ).

And yes, you can put your 2 legged replacement in the 2 holes marked + & -
 
Perfect, thanks Hyperion, I learn a little more every receiver I do. I'm sure as I dig further into this one I'll learn more and have more questions.
 
Took the four fuses out of their holders on the power supply to clean the clips. They were pretty dirty and corroded. Didn't clean up that well. Wondering if there are any options for fuse clip replacements. Did a little searching but there seems to be a million options out there and I wasn't seeing something that looked like it would immediately work. These fuses are also smaller than normal, is there a specific name for these tiny ones?
 
Started tearing into the Power Supply and realized that

F-1500A C10 1uF 50V 647-UKL1H010KDDANA
F-1500A C11 47uF 10V 647-UPW1A470MDD

are actually Bipolar caps. So I had to swallow 5 bucks in shipping to get $.60 worth of parts. Other than that the PS is done and once those get here I will throw them in and fire it up on the DBT. I'm anxious to move on, but I'm not going to do another board without first being able to make sure everything on the PS is good.

I did, however, regrease the output transistors while I wait. On this unit the legs of the transistors are soldered on like other through hole components. The old solder job had mounds and mounds of solder. Huge clumps. I think whoever did that did it to fill in the space at the side of the pad that has a slit cut in it. I didn't glob it on there; instead I left that one area free of solder and made sure the rest of the joint was clean and good. Here's a pic of one I did. For whatever reason that slit is there on all the output transistor solder pads.
 

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I've run into an issue.

Recapped the PS (just the caps, no diodes or transistors yet), fired it upon the DBT (no light emitted from bulb), set Offset and Bias, got a relay click. Everything was fine.

Moved onto the Driver board. Replaced all caps, the four 2sa726's and the variable resistors. Fired it up on the DBT and the bulb stayed about half lit and I get no relay click. When I tried adjusting Offset or bias for both channels my multimeter readings do not change. There's also a small vibration on the board you can feel if you lightly touch it.

Doing the bias adjustments on this unit you take out a fuse and hook your leads to the fuse clips. When I took the F-02 fuse out for the right channel and turned the unit back on the bulb did not glow and the vibration was gone. The bulb glows and the board vibrates when doing the same for the left channel. Which would lead me to believe there's something wrong in the right channel of the board, but I still can't adjust anything with the VR's on the left side (which leaves the bulb dim and there's no vibration) either.

Where do I go from here?
 
Update: took the board out and checked for solder bridges. Didn't find any, put it back in the unit, fired it up on the DBT and bam got a relay click and bulb went dim. I have no idea what could be any different. I can adjust the DC offset now too. However, I still can't adjust the bias. the right channel reads 28 mA and the left 29 mA, which isn't way out of spec which is 19 mA, but no matter what I do with the VR that's supposed to control it nothing happens. Maybe I just need to take it out of it's holder once more and magic will happen?
 
Well I figured out why I couldn't adjust the idle current. I hadn't moved my DMM lead into the fused socket! Noob moment.

Well I've got the whole thing recapped now (thanks to everyone who helped me with parts). It's working and sounding great and I've got the DC offset and idle current dialed in. Been listening to it for a couple hours and plan to use it for the next couple weeks before my brothers birthday to make sure it's all good. However, there's one last problem.

I had changed all the lamps to LED's before the recap and everything was fine. The left lamp of the tuner back-lighting flickered a little bit the other day but if I tapped the casing it would come back on so this afternoon I took the lamp housing out again to look for bad connections and make sure I had the bulb in good. Couldn't find anything, put it back, and now I have no lights at all! Everything powers on and works, but I messed up the power to the lights somehow.

Tried looking at the schematics and I'm pretty sure power is coming in from the K and L posts on the tuner board but I have no idea where to go from there. Any help? I'm so close and now I've got such a stupid little problem!
 
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Update: kept tracing wires and found a wire heading to fuse F05. It was a soldered in fuse. I took it out and sho nuff it's bad. So I'm glad to have figured out the problem. Ordering this for replacement: http://www.mouser.com/Search/Produc...5-Rvirtualkey50400000virtualkey504-BK/GMC-5-R

when I took out the light housing I had the unit off and didn't power back up until everything was back in place, so I'm unsure what I did that caused the fuse to blow upon power up... Does an LED upgrade in this unit need any added resistors? I have no idea about that but I've read sometimes they're installed with the LED upgrades and I didn't do that. Could that be part of it?
 
Enjoying this thread, there's an orphan 661 at the local GW that will be onsale for 50% off this Sat. Someone basically gave me a 771 and I love it, so hopefully I will fix the younger sibling. Good work and good luck! Cheers!
 
I bought this with the specific intention of gifting it to my brother. And I've come to like I so much I'm definitely on the lookout for the 771 or 881 for myself!
 
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