Working on another WOPL Convert ... a couple questions, including Pioneer SA-9100 rebuild

[e30m3mon]

A good friend is getting his JBL L100A (I believe they're called Century studio monitors...they were a hot ticket in the '70s) elements rebuilt. I have been expressing the virtues of WOPLiing his PL400-II, full soup to nuts with Full Complimentary backplane. It looks like I will be taking this on as a Winter project.

He currently has a PL3000-II preamp but complains the pushbuttons are noisy and ultimately wants a modern-day preamp with remote control as he will be tying in multiple sources, including a TV and DAC, among other stuff. The convenience of a remote volume and source selection are most important to him.

In the meantime he is looking to have his (original owned) Pioneer SA-9100 rebuilt that he might use the pre-outs to drive the WOPLed 400-II and then put the 9100 in another room at the house when he finds a preamp with remote, etc. for the 400-II.

Sorry to drag on, but the net is who rebuilds Pioneer receivers and would the combination of SA-9100 preamp be a good match for the WOPL'ed 400-II ?

 

[laatsch55]

The preamp sections of those series of Pioneer integrateds are rather good
Decent phone sections. I believe you are capable of restoring that 9100. A little tight and lots of caps and some crappy small signal Japanese transistors that need to be swapped.

 

[laatsch55]

Need a 400II core?

 

[Gepetto]

The preamp sections of those series of Pioneer integrateds are rather good
Decent phone sections. I believe you are capable of restoring that 9100. A little tight and lots of caps and some crappy small signal Japanese transistors that need to be swapped.

And the output cap is likely very inadequate and probably will be space constrained to substitute anything decent...

 

[e30m3mon]

Need a 400II core?

Thanks no, Lee ... he has owned his for nearly as long as I owned mine.

 

[e30m3mon]

The preamp sections of those series of Pioneer integrateds are rather good
Decent phone sections. I believe you are capable of restoring that 9100. A little tight and lots of caps and some crappy small signal Japanese transistors that need to be swapped.

And the output cap is likely very inadequate and probably will be space constrained to substitute anything decent...

Lee - you are too kind and overestimate my skills! And Joe, that kind of insight is where I am looking for someone who is familiar with the ins and outs of these receivers would know which transistors/caps/components to replace

 

[Gepetto]

Lee - you are too kind and overestimate my skills! And Joe, that kind of insight is where I am looking for someone who is familiar with the ins and outs of these receivers would know which transistors/caps/components to replace

Just about every brand cheaps out on that important factor Al. George will likely attest that it made a key difference in the PL preamp that he updated.

 

[George S.]

Just about every brand cheaps out on that important factor Al. George will likely attest that it made a key difference in the PL preamp that he updated.

Amen! Love the upgraded PL2000 S2 preamps. World of difference. WELL worth upgrading internal components if it's a piece you desire to keep. I sat at my bench the other night listening to a Biosphere N-Plants digital file on a upgraded PL2000, 400 WOPL, and Pioneer CS-99. Just amazing.
Was a great learning experience upgrading the preamps and great results. The same techniques used on the PL1000 S2 also paid off.

 

[e30m3mon]

Amen! Love the upgraded PL2000 S2 preamps. World of difference. WELL worth upgrading internal components if it's a piece you desire to keep. I sat at my bench the other night listening to a Biosphere N-Plants digital file on a upgraded PL2000, 400 WOPL, and Pioneer CS-99. Just amazing.
Was a great learning experience upgrading the preamps and great results. The same techniques used on the PL1000 S2 also paid off.

And many thanks to George for his 2000-II upgrades, as I also opened the covers to make that upgrade, as well as trim down the +/-18vdc coming out of the PS. Also rewired the balance control, per yet another thread.

 

[Steve K]

Is there a thread where all of these mods have been collected? And do they apply to a series1?

 

[George S.]

Yup, they apply to a S1 or any other unit. Joe taught to replace all ceramic caps with silver mica or film, all low value electrolytics not in the power supply with film, all high value electrolytics with audio grade electrolytics.
The 3 opamps can be upgraded with Browndogs from Cimmeron Technology.
The plastic phono jacks can be upgraded with Switchcraft metal jacks.
Here's a photo of a upgraded PL2000 S2. This unit will be further upgraded in the future with Joe's and Mark L's ideas of larger value films on the outputs and adding resistors to tame turn on thump. I could never have accomplished this on my own. I owe the guys a debt of gratitude. Thanks guys.
Also need to insulate a few more jumpers. And, this unit hasn't a single carbon resistor in it. All are low noise metal film. Does it make a difference? I don't know.

 

[mlucitt]

Does it make a difference? I don't know.

But it sure looks sweet!
I'd like to hear more about re-wiring the Balance Control, although I think mine works well.

 

[George S.]

The balance control. The S2s have a dual pot, the S1s have a single pot. The boards circuits are exactly the same where the pot leads are soldered.
At the time I had the one PL2000 S2 I had for decades. The dual balance pot was bad and tracking was off. Joe's solution was replace the dual with a single like the S1.
I can't recall the value at the moment, but I got a new single pot, Dremeled the shaft, installed it, and tracking was spot on. It brought the unit back to life in a very big way.
That unit is now disassembled and I use the board as a reference for mechanical measurements of components. The board is still very good and I may reassemble it, but I have other plans if I get time.
The other two PL2000 S2 I purchased later and upgraded have good dual balance pots. But, there are times I've considered swapping them for a single. I think the single pot offers better tracking. As I gain time and equipment I'd like to convert one to a single pot and compare it to a dual pot using the signal generator, scope, and Real Time Analyzer.

 

[e30m3mon]

The balance control. The S2s have a dual pot, the S1s have a single pot. The boards circuits are exactly the same where the pot leads are soldered.
At the time I had the one PL2000 S2 I had for decades. The dual balance pot was bad and tracking was off. Joe's solution was replace the dual with a single like the S1.
I can't recall the value at the moment, but I got a new single pot, Dremeled the shaft, installed it, and tracking was spot on. It brought the unit back to life in a very big way.
That unit is now disassembled and I use the board as a reference for mechanical measurements of components. The board is still very good and I may reassemble it, but I have other plans if I get time.
The other two PL2000 S2 I purchased later and upgraded have good dual balance pots. But, there are times I've considered swapping them for a single. I think the single pot offers better tracking. As I gain time and equipment I'd like to convert one to a single pot and compare it to a dual pot using the signal generator, scope, and Real Time Analyzer.

I found the images I saved from George's postings ... showing the before and after upgrade.

And I also think this was the potentiometer used for that upgrade ... https://www.mouser.com/ProductDetail/652-PDA241HRT02104B0

Lots of good treasure in Georges postings ... I highly recommend getting a glass of your favorite single malt and hunt his postings some night. Lots of buried treasures out there!

 

[George S.]

Wow, I forgot about those photos. Thanks Al!

 

[mlucitt]

I'd like to hear more about re-wiring the Balance Control, although I think mine works well.

Now I remember that post. It did not ring a bell because I have the PL2000, not the PL2000 Series II. This is one of the differences between the two units. One would think PL would have kept a proven design, and not adopt a more expensive and complicated solution to Balance control for the Series II. This design change must have slipped by the bean counters (or they had a ton of dual pots in the warehouse).

 

[George S.]

Like those GES97 transistors. All through their products.

 

[Gepetto]

Like those GES97 transistors. All through their products.

Have a hunch, buy a bunch...

 

[8991XJ]

I am looking for someone who is familiar with the ins and outs of these receivers would know which transistors/caps/components to replace

Well if you're calling the SA-9100 a receiver I see why you are out of your element with a full restore on that unit. But the pioneer gear is very well documented, they actually have useful service manuals. I've done an SX-5580, the tuxedo-clad SX-1050 receiver. Pretty easy to look over the parts list and select correct parts as all caps are identified by type in the list, just verify it is what's installed. The boys on ak are good at making pioneer gear come out right. If you want to know a guy, Chris Ready in my area is a good rebuild guy. Does lots of Marantz 4400s those quad, scoped receivers that have 65 pounds of parts stuffed into a 50 pound box.
There are transistor lists of what to replace on site and caps recommendations for good results I've read on that other site and I'm learning to do things that way.

A neighbor brought over an 8100 amp/7100 tuner and 9500eq he got cause he knew I messed with that junk. The 8100 and 9100 are very versatile amps

There is a 9100 restored pair on PHL CL for 1100 or so this week. Might not be out of line as much work as those would be.

Lemme know if you need a push or info.

 

[e30m3mon]

Well if you're calling the SA-9100 a receiver I see why you are out of your element with a full restore on that unit. But the pioneer gear is very well documented, they actually have useful service manuals. I've done an SX-5580, the tuxedo-clad SX-1050 receiver. Pretty easy to look over the parts list and select correct parts as all caps are identified by type in the list, just verify it is what's installed. The boys on ak are good at making pioneer gear come out right. If you want to know a guy, Chris Ready in my area is a good rebuild guy. Does lots of Marantz 4400s those quad, scoped receivers that have 65 pounds of parts stuffed into a 50 pound box.
There are transistor lists of what to replace on site and caps recommendations for good results I've read on that other site and I'm learning to do things that way.

A neighbor brought over an 8100 amp/7100 tuner and 9500eq he got cause he knew I messed with that junk. The 8100 and 9100 are very versatile amps

There is a 9100 restored pair on PHL CL for 1100 or so this week. Might not be out of line as much work as those would be.

Lemme know if you need a push or info.

LOL ! No .. I know the difference between the IA and R! Had a brain fart as I had just been looking a Pioneer received (question posted about the relay protection circuit) and had "receiver" on the brain when I posted this.

I downloaded the service book and will take a look after getting caught up on a few other things around here. I'll have a look over the AK website too - actually sent the owner of the 9100 there to look as well.

Thanks for the lead and info ... will reach out to you for Chris' contact info if the owner of the 9100 wants it done sooner. I'm going to start WOPLing his 400-II, so that will be a lot more fun.