Phase Linear 2000 recap questions

[MarkWComer]

I've been given a PL2000 for a rebuild, some electrolytics aren't available any more (and you're seen that I asked this elsewhere). I can't find the thread to see what others have done. Gone through both Mouser and DigiKey for parts that don't exist. I came across this "kit" on ebay, just wanted to ask the sages and mystics here on the board what their thoughts were on this:

https://www.ebay.com/itm/372918882723?​

I hesitate to buy this, but the guy has high feedback ratings, seems to be okay. Another reason I hesitate is that I bought a "kit" for my turntable caps for which only four caps were usable and conversation with the seller revealed that he doesn't speak English. Complete bust!

Another issue is that I'm not an audio engineer, not an electronics engineer, and I get bewildered by all the specs on caps- I just don't have the mental horsepower to select the correct components to do this job.

 

[George S.]

Mark W. , Here are photos showing silver mica caps, Panasonic ECW Polypropylene caps, 1% metal film resistors, Nichicon Muse filter caps, BrownDogs, SwitchCraft jacks, Dale ladder volume control, and a toroid transformer under a toroid shield.
I gained experience with everyone's help here to build this. Now I have some additional ideas and test equipment to improve things. Perhaps this winter I can get back to.
I think it sounds fantastic.
The one thing that gets overlooked in these is taking the pots and switches apart and cleaning them. The CTS made pots have a silver plated wiper ring that is tarnished and have hard deposits. Spray cleaners aren't good enough.

 

[mlucitt]

I hesitate to buy this, but the guy has high feedback ratings, seems to be okay.

Mark, this "Kit" has about $25.00 worth of capacitors in it (if purchased in high quantities).
Also, he is offering ceramic capacitors which are inexpensive and not optimal for audio.
I would pass.

Between George S. and myself, we can come up with a P/N list of the capacitors you need: C1 through C50.

 

[MarkWComer]

Mark, this "Kit" has about $25.00 worth of capacitors in it (if purchased in high quantities).
Also, he is offering ceramic capacitors which are inexpensive and not optimal for audio.
I would pass.

Between George S. and myself, we can come up with a P/N list of the capacitors you need: C1 through C50.

YES! Please send a parts list!​

 

[George S.]

I've lost my lists of caps and resistor values. I never did save the parts #s I ordered from Mouser and Digikey, and I never established accounts there, so no going back and looking.
I made my lists by looking up the values of each component in the manual, checking actual values on the board, and then finding them on the vendors website.
Many of the scans of the service manual schematic are not very sharp. Don's website with his links to the manual were the best I could find. I opened the schematic PDF on a large monitor and expanded sections of it for better viewing.
Couple things I'll do over on my next PL2000 build will be researching and using a smaller series of Dale resistors, and using lower voltage silver mica caps than are available at Mouser and Digikey. This will probably entail buying NOS on eBay. The issue is the larger diameter leads require enlarging many through holes on the board.
Same issue with some of the Panasonic ECW film caps.
Is it worth it? If you want a matching pre for your WOPLs, then absolutely worth it. But it's a ton of work just rebuilding the pots and switches. Then more work on the RCA jacks.
Maybe just recap the electrolytics and spray the pots and switches. Guess it depends on what the customer wants.
I do have NOS plastic RCA jacks if you need them, and can find the Dale volume control, toroid transformer and shield parts #s.

 

[George S.]

My next PL2000 project. A S1. From San Francisco, dirty, very dirty.

 

[MarkWComer]

I have an extremely good copy of the service manual, easy to read and excellent details, covers both S1 and S2 versions. Surprise- all the caps listed in the parts list coincide with what is on the board, there’s one extra cap listed that I can’t find inside the unit (omitted? Specific to S2?). I’m clear on all the values and voltages, but which ones are replaced with polypro caps? Which ones replaced with silver/mica? If I can get a handle on which type goes where I can figure it out except anything with a different value cap, and I see that you omitted two at the output stage. Granted- 1000μf electro for the PS could be a better exchange for the 470μf.

None of the pots seem to be bad, no noise, no scratchiness heard, I did shoot some Deoxit into those as well as the selector switch, no issues there. Input jacks show some oxidation, could use a contact cleaner scrub but I didn’t do that (yet). Nix on the transformer change, don’t think I need to take it that far. Honestly, it looks as if this was shrink wrapped and put in a freezer for 40 years! All the resistors look like 20% brown carbons, two red ones that I don’t understand- 5%?

I like this- simple preamp, no excessive gadgetry other than the ambiance circuit. I’ve been playing it for most of the day. Two oddballs are the lack of headphone jack and tape dubbing selector, neither are crucial. I might go hunting for one of these for myself! I assume this will be used with a WOPLed 400S1 that I did a while back for the guy (Mike Noland) who just wanted a cap & opamp refresh, also wants a polarized line cord (yeh, moot, but why not? I have Heyco pliers!).

Funny- no screen printing on the board for component ID…

 

[George S.]

Well, Joe taught us this .
Use silver mica for the smaller values, because they get very expensive as capacitance increases.
Use Polypropylene film caps where silver mica is too expensive. Favorites are Wima, followed by Panasonic ECW. I use Panasonic because they're easier to fit than WIMA.
As film cap capacitance increases, they get huge and won't fit the board, so you'll have to use electrolytics.
Then there is rule about not using film caps in the filtering after the rectifiers. Think it has to do with them needing to be polarized, while film and silver mica are bipolar.
Finally, absolutely no ceramics are allowed.
I have 8 electrolytics total in the preamp. Many expensive silver mica, and the rest are film.

 

[mlucitt]

there’s one extra cap listed that I can’t find inside the unit (omitted? Specific to S2?).

Mark, you are correct. I could not find a C26 in my PL2000 Series I and C25 is deleted in Series 2.
George and I were corresponding during our PL2000 upgrades; he was doing a Series II and I was doing a Series I. He may not remember but he showed me a picture of his Mica Capacitors in the Mouser bags, so I captured those P/N's. We also discussed the best substitutions, and I captured and recorded most of it.

I will post this document as an attempt to capture the information you require. If it has a Mouser P/N, I verified that it is correct and the prices are current as of today. George can substantiate the information and correct any obvious errors. Here you go:

 

[George S.]

Mark W.. 2 points on the pre need addressed. Joe brought this to our attention.
1. Start at the main outputs working back. The trace leads to two polarized caps that are in series, effectively making a nonpolar cap. These two can be replaced with one film and a jumper, or one huge film.
2 You understand the WOPL star ground and why there is one, and only one ground. This pre has two grounds. The left and right rear screws on the PCB.
Keep the left rear screw by the transformer as the star ground. Take a appropriate size drill bit in hand, and carefully cut a little copper away from the right screw hole. Install the right screw with a nylon washer so it's insulated from the ground plane. Then add a jumper bridging those ground planes.
And if your curious why that transistor that up front in the LED circuit only has two legs being used.
They're using it as a zener diode to power the LED. You can let it be, or replace it with a zener or resistor.
And. Wall outlet voltage is now higher than when this pre was built, and this may impact longevity of your opamps Visit the opamp data sheet and review the voltage range. This won't affect the phono opamp as it gets lower voltage than the others. But check your rail voltages before installing the BrownDogs. Lee had issues on a build with too high voltage as did I on every unit.
Have fun! It's a great, simple pre with nuances that need addressed. For me it's been a great learning platform.

 

[MarkWComer]

Wow- this is great!
Thanks for compiling this information- 100 lb. of gratitude to both of you!
I never would have caught the grounding issue, I wouldn’t have even noticed or looked for it.
Will definitely check rail voltages…

 

[MarkWComer]

Mark, you are correct. I could not find a C26 in my PL2000 Series I and C25 is deleted in Series 2.
George and I were corresponding during our PL2000 upgrades; he was doing a Series II and I was doing a Series I. He may not remember but he showed me a picture of his Mica Capacitors in the Mouser bags, so I captured those P/N's. We also discussed the best substitutions, and I captured and recorded most of it.

I will post this document as an attempt to capture the information you require. If it has a Mouser P/N, I verified that it is correct and the prices are current as of today. George can substantiate the information and correct any obvious errors. Here you go:

Just a note:
Two of these from Mouser were noted as EOL, so I ordered 3x. C39 noted as backordered, I omitted (this one goes parallel to the resistor on the switch).

Mouser does supply C44, but is a non stock item and minimum order is 2,000. TAW has no order form.
Mouser also stocks C15, C16, so a separate order from DigiKey wasn't necessary.

If anyone else intends to order, note the few EOL devices and get extras!

 

[mlucitt]

Clearly, ordering these older spec parts is a moving target. When I looked - C15, C16 were not available at Mouser, now they are? Sheesh!
TAW is awkward, you have to fill out a Parts Inquiry, then they contact you with the amount in stock and a price. It was the only place I found that had genuine German WIMA 1uF Polypropylene film capacitors that would fit the lead spacing holes. They were not too expensive, so I bought (10). If you want one for C44, send me a PM.

 

[MarkWComer]

Curious about this:
Why is a gob of silicone bathtub caulk on these?

 

[Hexis22]

Curious about this:
Why is a gob of silicone bathtub caulk on these?
View attachment 77939

Helps provide stress relief to leads and solder joints of tall components.

Similar to tie wrapping wires together…

 

[vince666]

Curious about this:
Why is a gob of silicone bathtub caulk on these?
View attachment 77939

more than silicone, it might be hot glue.

 

[MarkWComer]

more than silicone, it might be hot glue.

No, not as stiff as hot glue. This is soft and squishy.

 

[J!m]

What Hexis said.

 

[Vynuladikt]

Probably more for shipping protection than anything else. Vibration of ships, trains and trucks. Better there than the stuff on the board that eats the leads away. Very common in stuff I've worked on.

 

[MarkWComer]

Probably more for shipping protection than anything else. Vibration of ships, trains and trucks. Better there than the stuff on the board that eats the leads away. Very common in stuff I've worked on.

Right… not the first time I’ve seen it, never knew why it was there.