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Sansui 9090db, recapping..??

S

Sagacious

Member
Im thinking about recapping my 9090db, what is the best cap to get is there really a big difference between elna cerafines, black gate super e's and mundorf silver-gold-oil?

my thought would be the mundorf's but i could be completely wrong. is it worth my time to FIND some black gates (if possible) or spend all that money on mundorfs? or would i be completly fine with cerafines?

im just getting started in the DIY audiophile stuff but i've recapped a few inverter board on lcd's. is there any reason i should need a polarized cap for the 9090db? i assume i want a non polar. all thoughts appreciated.
 
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Today's Cerafine are better than what Sansui used in this. Black Gates are overpriced and maybe overkill and Mundorf's too,and most of the caps are polar.

MLytic's could be good in some places like power supply for driver stages.

Replace polar with polar, bipolar with bipolar

Cerafine everywere you find the suitable replacements value except fot the "originals orange" Elna's ,(they are special low noise) use Silmic II for them.

If you need Bipolars,go for Nichicon's ES BP
 
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Hello, thats quite a jump, from recapping an LCD inverter board(which I've done) to recapping an involved big nice receiver like the 9090db(which I've never done).

Kudos to you if you can do it. I'd probably blow the thing up and lose all that nice gear and work. :smoke::tears:

Not trying to discourage you, just saying. Good luck.
 
Welcome to AK and the Sansui forum.
As the other members have said caps today are generally better quality than used in it when new, not all values will be available but generally you can find suitable substitutes. Look over the sticky note thread on this subject, be careful to match polarity and take lots of pics as you go.
Replace any fusible resistors while your soldering iron is hot.
 
TrexT said:
Hello, thats quite a jump, from recapping an LCD inverter board(which I've done) to recapping an involved big nice receiver like the 9090db(which I've never done).

Kudos to you if you can do it. I'd probably blow the thing up and lose all that nice gear and work. :smoke::tears:

Not trying to discourage you, just saying. Good luck.
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no, that is a good point. maybe im being over confident. is there is a reason i should be worried? I figured, since it's a non multi-layered PCB then it would be pretty hard to fail, right? from what im hearing i'll just make sure i pay attention to the values i replace and the polarities when relevant.

im surprised to hear the blackgates and mundorf's being a waste of money/time. every article i've read swore by them, even said they were worlds better than the wood casing/beeswax modified cerafines. but this is why i posted, i'll take your guys' word for it. they're certainly cheaper.
 
Sagacious said:
<snip>....im surprised to hear the blackgates and mundorf's being a waste of money/time. every article i've read swore by them, even said they were worlds better than the wood casing/beeswax modified cerafines. but this is why i posted, i'll take your guys' word for it. they're certainly cheaper.
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They are not a waste of money/time - but there is a limit to how much it is practical to spend on such a project - the recommendations you have had already are absolutely fine (except I might use Panasonic FC and Nichicon FG instead :D)

BTW: 'Black Gates' are not made any more.
 
Hyperion said:
They are not a waste of money/time - but there is a limit to how much it is practical to spend on such a project - the recommendations you have had already are absolutely fine (except I might use Panasonic FC and Nichicon FG instead :D)

BTW: 'Black Gates' are not made any more.
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ok thats what i needed to hear. yea i knew the black gates weren't made anymore but i see sources online that still list them with limited quantities.
 
Mundorf's silver gold and oil are mostly suitable to upgrade amps like tube amplifier

They are big and pricey and only a few ones are requiered in the signal path to hear a big difference.
 
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i could be wrong but the mundorf's all seem to be axial but leaded on opposite ends (is there a name for this?) seeming to be not very physically suitable in design for an application like a 9090db where most all is twin-leaded on one side.
 
Most mundorf's series are axial and bi polarized NON electrolytics.

Some mundorf's Mlytics are polar electrolytics.

Electrolytics (even bi polars) have some filtering caracteristics that film caps dont have.

Don't try to replace every bi polar with film caps , Sansui engeneers knew what they do when they install an electrolytic somewere.
 
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Blackgates have been out of production for a few years. There may be some stock around but it's drying up. I use Panasonic FC/FM or Nichicon PW series very high quality inexpensive caps. Way better than anything Sansui used.

- Pete
 
One of the bigger challenges on the 9090db is the dolby board. If it hasn't failed yet, it will. It's a double sided board and has lots of pass thru joints that were just drilled and flowed with solder. That shrinks and goes open over time. Only real solution is to desolder the joints and insert wires to bridge the pads on either side. Old capacitor snips work well for that, but it's time consuming and a lot of the pass thru joints aren't all that obvious or are hard to get to.

Easiest way to tell is if your pushbutton array goes intermittent or flakey, or you have a lot of crackling noises in the output.

Here's a good write up on what's involved.

http://www.audiokarma.org/forums/showthread.php?t=103856

* I've got a similar job in my future ... The QRX 9001 had the same issues. Been working my way up to a full recap on that. I've also got an 8080db with the same board as yours that will need to be overhauled eventually.
 
Thanks for taking the time to post all of this good information. I have about 5 9090DB receivers and one 990DB. My plan is to totally restore my cousin's 9090DB and my 990DB because both of them will be "Keepers". The others will ultimately be sold off in the distant future. I am moving and can't get to it yet. I truly appreciate your effort looking up all of those capacitors and resistors. By the time the new components go bad/wear out, I will be no longer on this earth and someone else can "Do It Again!"
 
I try to glean all I can as a no-soldering fool (I'd need 3 hands as I burn myself just making guitar cables) from these posts, as I have a 8080DB and although I've had it professionally recapped I'd like to, someday, supercharge it with some big-dog caps. I'll get around to doing it when/if my dolby board goes south. This (these?) receiver(s) is/are among the best and most popular 70's Sansuis, and I'd be curious how many actually sold during their production years. I've seen and talked to more people here that own these beauties than any other receiver.
 
Here's mine ...

QRX9001benched.jpg


Somewhere in there anyways. :D
 
I'd guess that the same figures pertain (relatively speaking) for the 8080DB as well. Sorry about the sidertrack...
 
Tnsilver, there were no 9090DBs made in 1981 or 1971. If memory serves They were produced between late 1976 and early 1978 What is your serial number?

Its probably something like 827115000 meaning line 82, November 77 production and #5000 off the line that month. For what it's worth, I don't think I've ever seen production that exceeded 3000 or so in a month so if your serial number ends with 5000, it's indeed special.

The 9090DB is arguably the most popular receiver Sansui ever built but I'd be surprised if there were more than 70,000 or 80,000 made. That would be a good project for someone with time and an affinity for numbers to estimate.

When estimating production volume, keep in mind that Sansui may have made several different models on that line during the month. The numeric sequence remained the same on the line regardless of the model being produced. Take a look at the Sansui database. It's a wonderful resource for this kind of information.

- Pete
 
tnsilver said:
naderpe said:
Those are Polyester. Not hard to find. I use Nichicon YX series for these. I was referring to Polystyrene caps - not Polyester. See attachment image.
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Somehow, I got associated with the Polystyrene comment in the thread? Could have been a "cut and past thing" because I do know what Polystyrene caps look like and that link to Mouser is not a Polystyrene? I don't remember making that comment, but who knows!
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