WTB: STK3102-IV pre-amp module for Marantz PM80 amplifier

[rbroer]

I'm looking for a STK-3102-IV pre-amp module to repair a mates' Marantz PM80 amplifier.
They're quite hard to find, and not produced anymore.

Any links to electronic part suppliers (pref.) in the Netherlands are also very much appreciated.

[guido]

I got one, but there is a PM64 around it
Mine failed years ago too, i just ordered a new one at a local hifi shop (more electroshop) who does it's own repairs (Balter, Sittard). They ordered one at Marantz, dunno of they are still available.

I am willing to trade the PM64 to anything else nice, i'm not using the PM64 anymore. Anything nice to offer that spins silver disks ?

I did notice it got very warm after i replaced it (during normal operation i guess), so i mounted a coolingfin on mine. The amp is not bad, but my current setup is (much) better.

Groetjes,

[guido]

Edit,

Not shure if it is a IV (is that is a revision level?).
probably older.

mvg,

[rbroer]

It must definitely be a IV version.

Sorry, nothing to offer

He just lost his job last Friday, so this repair is on a budget for sure.
Managed to find one, but at a steep 55 euro's
Hoping to find a place where he can do better

[DigitalJunkie]

Hey gang..Just ran across this thread while searching the site..

I was wondering if anybody had any info on the STK3102-III datasheet,pinout,etc?

I've got a Sansui A-1130p with one,and I think it's toasted in the left channel of this module. Bias is okay,everything seems to be in order,except a very low,distorted output in the left channel.
I suppose I could just order another one,if I can find one again.The last couple times I repaired this amp I've ordered them from MCM electronics.

[rbroer]

Sounds like the same symptoms the PM80 has.

Found a new STK-3102-IV, put it in, but unfortunately no success.

I must admit I didn't check the output stage, was almost sure it should be this chip

I don't feel like repairing it, too warm, wanna do nice things
But somehow I feel obliged, since I advised this mate to buy this chip; silly me

[DigitalJunkie]

Well,I replaced it with an older module I had around (from the last time I repaired this amp.) But the left channel is still fubar.. I have another one too,but I think it's also fried..I'll solder it in and see..

I'm almost starting to suspect something *before* the STK module,somewhere in the preamp circuitry..but we'll see..
I'll probably order yet another STK module,and hope that it will fix it once and for all!

I'm half tempted to scrap this amp for parts,but it's soo close to working...

[kangaroo]

Dear rbroer,
Have you had any success in locating this module. I have the same problem with the same model Marantz. I am going to remove the module and replace it with some simple " home grown" circiut on matrix board. If you want the details, I will gladly supply them. I cannot see why Marantz took this approach in the first place just to save a few discreets.

[kangaroo]

just a bit more for rbroer. This amplifier is worth saving just for some of the features it presents in saving your loadspeakers from being incinerated.

I do not have a circuit diagram but, I can see that it has some sort of monitoring circuit which will prohibit speaker selection if there is a power-amp fault. The relays which select system 1 or 2 cannot operate if there is any D.C. offset on the output.

For this reason alone, I will continue to get this amp. up and running with some simple circuitry to replace the stk 3102 module. At this point, I think it can be replaced with a dual op-amp, each section driving a couple of complentary pairs or even complimentary darlingtons.

Any comments are welcome.

[rbroer]

Originally posted by kangaroo
Dear rbroer,
Have you had any success in locating this module. I have the same problem with the same model Marantz. I am going to remove the module and replace it with some simple " home grown" circiut on matrix board. If you want the details, I will gladly supply them. I cannot see why Marantz took this approach in the first place just to save a few discreets.

Yes, eventually I did (some small place for radio parts, I bought the final two, just because they seem quite obsolete).

It didn't do the job though.

Amp got fixed later, was a mechanical input selection problem I think.