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New Sansui 9090db

J

James Deeley

New Member
I just picked up a 9090db from a buddy. He hadn't played it in about 4 years and it was pretty dusty. I know about the dolby issue so I dusted it off and hooked up a turntable and cd player and checked inputs. Aside from some scratchiness everything seems to be working just fine. I was planning on opening it up this weekend and give it a good cleaning but I was curious if there's anything else that would be recommended before putting her into regular rotation? I am not ready to send it off for a full restore but is it just testing the hifi gods to think I can get away with just playing it without more preventative maintenance? Sure is a beauty though! Thanks!

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Congrats on purchasing a fine receiver.

You might consider changing out the fusible resistors. I haven't heard of them doing any damage when they go bad but I'm sure there are people on here who would know if it is possible.
 
James Deeley said:
I just picked up a 9090db from a buddy. He hadn't played it in about 4 years and it was pretty dusty. I know about the dolby issue so I dusted it off and hooked up a turntable and cd player and checked inputs. Aside from some scratchiness everything seems to be working just fine. I was planning on opening it up this weekend and give it a good cleaning but I was curious if there's anything else that would be recommended before putting her into regular rotation? I am not ready to send it off for a full restore but is it just testing the hifi gods to think I can get away with just playing it without more preventative maintenance? Sure is a beauty though! Thanks!

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At this stage, I'd not play it until DC offset, Bias and overall power supply health was improved.

If she goes bang, the magic smoke goes out. Please consider this receiver (I had a 9090db, and had it restored) as an investment as well as a lovely lady that deserves an overhaul before burnouts.

I wish you luck, and fun times. This receiver, IMHO, was the overall best sounding receiver I ever owned, and I had most all of the big dogs.
 
Its always a good idea to get some background history & details when acquiring a vintage amp, in this case you got it from a friend, so he would be the one to provide the info - is he the original owner, was it ever serviced before in the past 45 years of its life?

Just like buying a car- you cant go by the outer appearance itself- the hood is opened up to see whats going on inside to tell more of the true story of its condition, so ditto with the 9090db- cover off and see how the components look on the circuit boards and so forth.

After 45 years, and after sitting inactive for a period of time, it is long enough for components to be far past their useful lifespan and drift off spec, or for other typical issues to happen, be it loose/cold solder joints and so forth.

If you intend to make this unit a showpiece in your hi fi system, it would be beneficial to have it checked out by someone with solid experience on Sansui amps, especially the dolby issues which takes a bit of know-how, not something for the novice to handle, a good tech can check all these things and optimize its performance to ensure trouble-free reliability in the years ahead.
 
Thanks for the feedback! It's my understanding that it did get a once over sometime in the last 7-8 years but I may bring it in to a local tech anyway and have them peek under the hood.
 
Hey there! Holding pattern right now. There's a local tech that I'm going to bring it to with the suggestions you all had. RIght now he has a Yamaha A-1 integrated he's working on for me so I like to keep the repairs to just one at a time! ;) I'll be sure to report back when I have updates.
 
onwardjames said:
Any news for us, James?
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Happy New Year, everyone. So I just got it back from a tune-up with a local tech. He cleaned it all up, soldered some loose connections, checked all the caps and replaced a couple, set bias and DC offset. He said it was in great condition and just recommended whenever I use it to rotate the Dolby knob 15-20 times first to keep that section functioning.

Now my next challenge is finding a stereo rack large enough to accommodate such a huge receiver. Seems nothing modern is designed for such a large receiver.
 
I do hope your tech replaced those fusible resistors on the driver board, you did t mention them being done with the other work. If not, get them done ASAP. If they go far enough off spec, it will typically blow one (or both) channels with non real warning.

Outside of that, it's an excellent acquisition, so take good care of it, and spend lots of time listening to it. It's worth it.
 
James Deeley said:
Happy New Year, everyone. So I just got it back from a tune-up with a local tech. He cleaned it all up, soldered some loose connections, checked all the caps and replaced a couple, set bias and DC offset. He said it was in great condition and just recommended whenever I use it to rotate the Dolby knob 15-20 times first to keep that section functioning.

Now my next challenge is finding a stereo rack large enough to accommodate such a huge receiver. Seems nothing modern is designed for such a large receiver.
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Did he replace the fusables? I'd rather he do that and not anything else listed, because you still have a time bomb.

Also if he didn't, find a new tech that knows what he's doing....
 
@James Deeley having just got it back, I know you're happy, and maybe my comrades don't put any varnish on their words, but that's because what they say has ramifications for you and that gorgeous receiver (and she is truly a beauty).

Get them fusible resistors replaced, assuming your fella didn't already.
 
James Deeley said:
Happy New Year, everyone. So I just got it back from a tune-up with a local tech. He cleaned it all up, soldered some loose connections, checked all the caps and replaced a couple, set bias and DC offset. He said it was in great condition and just recommended whenever I use it to rotate the Dolby knob 15-20 times first to keep that section functioning.

Now my next challenge is finding a stereo rack large enough to accommodate such a huge receiver. Seems nothing modern is designed for such a large receiver.
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Do not overwork the Dolby switch. The shaft between the wafers will work it's way out eventually and stop working altogether. That tech apparently isn't a Sansui Guru or he'd know that. And with that said, he also may not know about the fusible resistors failing over time.

Where are you located? There may be a Sansui Guru near you who could properly service the unit.
 
Skywatcher said:
Do not overwork the Dolby switch. The shaft between the wafers will work it's way out eventually and stop working altogether. That tech apparently isn't a Sansui Guru or he'd know that. And with that said, he also may not know about the fusible resistors failing over time.

Where are you located? There may be a Sansui Guru near you who could properly service the unit.
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I’m in Portland, OR. Happy to take any advice if there’s a local Sansui guru.
 
The opens and general scratchy-ness is not a function of the Dolby selector switch. It is the PCB vias that have cracked over time. Rotating the switch puts stress on the Dolby board and closes the opens. No way to fix it other than removing the board and desoldering the switch and ribbon-cables so the vias can be repaired. Photos below show board with cracked vias and the amount of desoldering necessary to get it all out. Not hard just tedious.....
 

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SansuiSteve said:
The opens and general scratchy-ness is not a function of the Dolby selector switch. It is the PCB vias that have cracked over time. Rotating the switch puts stress on the Dolby board and closes the opens. No way to fix it other than removing the board and desoldering the switch and ribbon-cables so the vias can be repaired. Photos below show board with cracked vias and the amount of desoldering necessary to get it all out. Not hard just tedious.....
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Yep, I've pinned all of the ones I came across, and changed out the green flat ribbon cable on the earlier models. Plus disassembled the switch and cleaned every individual wafer removing all the black tarnish. When I do that, I put a couple of "burrs" on the end of the shaft so it grips the plastic "slot" much better so it doesn't walk it's way out.
 
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