Sansui 7000

I have a Sansui 7000 that the left channel had been intermittant and now is out. Would like to change the transistors. Previously tried cleaning and it would still be intermittant. It has Hitachi 2sc680 and Hitachi 2sa566 transistors. What would be a good replacement for these. Have been a lurker for years. No techie, just an oldschooler who enjoys music with that Sansui sound. Sansui reminds me of old time live club sounds.....some people describe it as tube like. Thanks for any help.

Don't forget to use the search function. This was the second hit on the list, just below this thread.

http://audiokarma.org/forums/showthread.php?t=405141&highlight=2sa566

Hi Oldschool00, welcome to AudioKarma. It's unlikely the output transistors are the cause of your intermittent channel. It's much more likely to be dirty controls. The 7000 has a lot of switches. They all need to be cleaned.

- Pete

Thanks for the info. I am retired, but work a nite job to supplement, so can't always respond timely. I have cleaned the switches 3 times. It did appear to correct temporarily, but came back. The last time I played it, the right channel was totally out. I will try to clean the switches again this weekend and test. Any other recommendations would be appreciated.

I have owned 3 eights and a 9090db, but I chose to keep the 7000. Could not tell much difference in the sound of the eight versus the 7000, but the tuner reception seems to be better on the 7000, so I decided to keep it. To my ears the eights and the 7000 sounded quite a bit better than the 9090. Again, thanks.

You can clean pots to death. What are you using to clean them? Are you getting the solvent INSIDE the switches and pots?

- Pete

Hi, I have a 7000 too, & really like it. :thmbsp: This one was the hot rod of the single digit series, as you may know. The thing you need to do is, open her up good, & use DeOx on ALL the controls, not just the rotary switches. The pushbuttons will cause problems exactly like you describe, if they're dirty. I had to clean everything 3 times altogether, & it's STILL a little funky, so I just wedge a little rubber washer in between the problem push buttons & the faceplate, to keep them depressed in just the right position. I know, it's not exactly a good and permanent fix, but it works. I have other Sansui gear, without issues, but the 7000 just has something special about the sound, mostly the low-end, like you mentioned, that I just really like. :thmbsp:

I use different techniques for switches and pots. Really dirty switches often need a stronger solvent. D5 Dexoxit is not a strong cleaner so I'll use a contact cleaner followed by D5.

Pots are a different story. Older carbon film pots can be killed with solvent like a strong contact cleaner. It's best to use faderlube and 100% deoxit. Newer pots like the stuff from the mid 70s and later are typically more robust and can usually be cleaned with D5 followed by fader lube.

In either case, the cleaners need to get onto the working surfaces of the device being cleaned. That's often impossible without a large degree of dissassembly to get access to whatever holes are available in the device. I'm afraid that some newbies, not wanting to do the necessary disassembly, simply spray away wasting the solvent and not doing squat to clean the device. Then when it doesn't work they say I cleaned it now what? That can start a death spiral as well meaning posters lead the newbie down the rat hole

I'm not saying that's the case with this post but its something to be careful of since we don't know the skill level here.

- Pete

I have a clean 7000 that sounds very nice. It was my first nice vintage stereo and I don't think that I will ever part with it. I wish it had come with the microphone that was sold with it. I could use it for a vintage style karaoke machine (just kidding).

From what I have been able to determine from posts here on the forum it is similar to the eight and other single digit series from the early 70's. How does this compare to the eight in build quality, for those who have both? Mine seems like a really well made unit with machined knobs and solid chassis and cabinet. If the eight is superior to this then I will be searching for one of those.

Some of the information that others have chimed in about the 7000 being differentiated from the eight and marketed to military personnel has validity. I called my father (who saves everything) and he had his old copy of the 1972 Aafes (Army Air Force Exchange Service) catalog and brought it to me. I looked in the electronics section and sure enough it was there. List price was $201 and one of the most expensive and totl receivers they carried. Keep in mind that Aafes was not in the high profit business but more of a service to the guys in the service. Does anyone know what an eight listed for in 1972 on the regular commercial market? If there was a build quality difference, as someone in a different thread mentioned, could it have been to keep the price reasonable for this military personnel model?

The Eight, Eight Deluxe and 7000 all have different and unique amplifiers. All three models share the same basic chassis layout and very similar apearance but they are not the same under the bonnet. You will also see differences in the functions of the push buttons.

There are also two distinct model variations of the Eight and 7000. The early Eights did not have relay based protection circuit the later ones did. DCinDC posted pictures of major circuit board differences during the production of the 7000. I don't remember the details but if you do a little digging I'm sure you can find his post.

- Pete

The 7000 build quality is a step down from the Eight and Eight deluxe as regards the machined aluminum covers over the output transistors. Also the tone controls are detented pots not step (switched) attenuators with discrete resistors.

I believe the 7000 was PacEx/EuroEx only, or IOW made only for the BX system and GIs. GIs always wanted more power. I have no proof, that's just what I think.

The 7000 version differences are a MUCH smaller preamp/tone board, and a non shorting mic jack.

I have a 7000 in the box, with the mic, and all paper work. Just refurbing it now.

The Eight has the highest build quality of them all, but I prefer the Eight deluxe.

If you are on a budget a Six will blow your mind for their cost on the open market. I'm not selling any of mine for less than $100, which they don't often hit on auction.

There's not a Marantz or Pioneer left in the house, but there's half a dozen or more 6, 7, 8, and 7000s. Just sold my keeper :cry: Eight Deluxe to an AK'er. A Seven replaced it, but I will probably replace that with a Six.

The best mod you can do to these is replace all the small signal transistors with modern low noise substitutes. I did this to the phono preamp on an Eight and it was DEAD quiet after that. Inky black background.

oldschool...
The way to clean the switches is remove the face AND the escutcheon over the dial. Pull off the switch buttons and squirt cleaner right along the switch axis. THAT gets them clean, although I have to say, these pushbuttons on these models stay cleaner longer than on other vintage receivers, in my experience.

I didn't realize the 7000 had tone pots instead of the stepped attenuators. That's a big difference in build quality. Its one of the things that makes that series so unique among receivers. I've also heard the stories about the 7000 sold exclusively through the PXs but haven't seen anything to either confirm or deny it.

- Pete