Phase Linear 200 rebuild

[WOPL Sniffer]

huh?

 

[laatsch55]

Never did a 200, did a few 300's....nice job..

 

[oldphaser]

Ha.... Just noticed the meters are going from right to left instead of left to right... Guess I had better turn the board around... DUH.......

Perry,

Been there done that. It's a bitch.

Ed

 

[oldphaser]

It aint no wopl but it bad for a 100WPC amp. Gonna burn it for a couple days. Then I'll hook it up to the CornScala's. They are way more efficient so we'll see how she sounds then.

Perry,

The 200 series 1 amps were the worst amp Phase Linear ever built!

Trying driving both channels into a 4 ohm load into clipping and tell me what you see.
Maybe with the MJ's in there it won't be assymmetrically clipping anymore.
Because of this assymmetrically clipping, Phase Linear never rated the 200 series 1's into a 4 ohm load.

The later 400 series 2's were fully comp and also never had any problems with clipping symmetrically.

Ed

 

[orange]

If you can keep it stable at around 6-6.5 ohms and 80 watts for awhile (and I'm betting you can) and do want to sell it eventually, please keep me informed so I can save for Christmas. Or so.

 

[Northwinds]

I am pretty confident that with the MJ's and Perry's undeniable skills in redoing amps will garner someone and very nice amp. Perry would not let it out of his yeard if it was not ready to roar and last for many many years

 

[Gepetto]

The PL200 S2 is a sweet sounding amp, not a lot of power but very pleasing sound. As Ed said on the S1 versions.

 

[laatsch55]

The 300's sound good...

 

[oldphaser]

Gee, thanks Ed, luckily I wasn't trying to sell it here. That could have killed a sale.... Anyway, I'm going to put her on the test station and see if it's as bad as you say.

Perry,

I have (2) of the Phase Linear 200 series 1 amps I dragged all the way here to Connecticut. At some point they will go up on ebay. I just wanted to be honest about what one can expect out of these amps. Essentially, I would not recommend anyone use a 200 series 1 amp to drive a 4 ohm load.

I wish I had some extra Phase Linear 200 series 2 PL19 pc boards (Phase Linear part # 210-0161) to replace the earlier 200 series 1 PL19' pc boards (Phase Linear part #210-0043). I've done it in the past with other series 1 amps I've owned.

Perhaps you or Joe could get some boards made. I know I would be up for buying some.

Ed

 

[oldphaser]

I looked and the 4 pin TO-3 socket is not available anymore. You'd have to salvage the sockets off your original boards. The 3 pin mounts won't work on the boards.

Perry,

I am going through all my Phase Linear literature now.
The Phase Linear part number for the TO-3 sockets (used in the 200) is 121-0071.
My Phase Linear master parts catalog shows that it was made by (EEI) Electronic Essentials Inc. (originally in Woodside, NY). EEI's part number was 1004-22.
NOTE: Keystone Electronics is now making/selling a lot of EEI TO-3 sockets but apparently not this one.

I believe I may have a bag of new old stock TO-3 sockets (for the 200) I got from Dean years ago.

Ed

 

[oldphaser]

Phase Linear 200/200B Series 1 Amplifier Service Bulletins

Perry,

Here are just a couple of the service bulletins that were issued for the Phase Linear 200/200B series 1 amplifiers.

Time permitting, I will scan a few other 200 series 1 documents which may not have been issued as service bulletins and/or were not included in the service manuals. These would include:

1.) "FINAL ASSY & SCHEMATICS 200 AMPLIFIER 402570 E VERSION"
2.) "01 ASSY, 200 POWER AMP, P.C.B PL19 65502 DWG. NO. 402555 REV NEW"
3.) "01 ASSY, 200 POWER AMP. P.C.B. PL19 23512 DWG. NO. 402555 REV D"
4.) "01 ASSY DISPLAY BOARD PL 24 60503 DWG. NO. 402558 REV NEW"
5.) "01 ASSY DISPLAY BOARD PL24 60503 DWG. NO. 402558 REV A"
6.) "PCB ASSY. SCHEM. RELAY CONTROL 200B PL31 DWG. NO. 210-0087-0 REV A"
7.) "RELAY CONTROL ASSEMBLY 200B PL31 DWG. NO. REV A"

There are a few others as well.

Ed

 

[oldphaser]

I spotted in the manual where there ARE versions that only take the NPN's and as soon as I gave that a shot, she came right up. The bias was high, and depending on which error in the manual stops you (one place tells you to measure the voltage drop on R24, one tells you to measure it at R25), it can take you all day of subbing in resistors into the R13 position (that's where you change values to change bias) to get the bias to the 20mv-50mv range and that is IF YOU ARE MONITORING IT IN THE RIGHT PLACE... Holy Shit, there aint much to the amp but it was a real headache.

Perry,

The 200 series 1 service manual is not so good. (An understatement on my part. LOL!)

I am glad you were able to figure out the bias setting. I'm not exactly sure how but I'm glad you did!
I had to learn the hard way (many years ago before I met Dean) that Phase Linear service manuals can have errors in them!
This one drove me nuts!

Anyway, there was a 200 service bulletin "Subject: Corrections in 200 Service Manual".

"We have discovered a set of misprints in the 200 service manual. In order to avoid confusion in measuring and adjusting bias for the 200, PLEASE MAKE THE FOLLOWING CORRECTIONS AS POSSIBLE:

1) Page 13, step#8: correct R24 to read R25.
2) Page 14, step #17; correct R24 in two places to read R25 in both places.
3) Page 16, step D: correct R25 to read R25.

All bias voltage measurements are to be made across R25, NOT R24 as misprinted in the manual. Thank you for your cooperation."


I took a quick look at my Phase Linear 200 series 1 service manual ("prepared 1/77"). I am not sure if a newer revision was ever published.

I don't think the service manual mentions R25 anywhere in sections V "Test and Alignment Procedure" or section VI "Troubleshooting Guide".

V "Test and Alignment Procedure"
Cold Bias:
Step#8 "Using a suitable DC voltmeter, measure the DC voltage drop across R24 (.68 ohms) in each channel.
Verify between .010 and .050 volts DC. Otherwise refer to section VI-D."

Warm Bias:
Step #17. "Once again read the DC voltage drop in each channel. At normal (warm) operating temperature there should be between .010 and .080 volts DC across R24. Units exhibiting bias voltage greater than .080 volts will develop excessively high idling temperatures, and should be modified in according to section VI-D#1."

VI "Troubleshooting Guide".
D. Bias and Thermal Stability
"As outlined in Section V, the bias voltage measured across R24 should NOT exceed 0.080 VDC; otherwise the unit will exhibit excessive idling temperature, or possible thermal runaway and subsequent failure."
NOTE: Steps 1 and 2a thru 2e are too long for me to reprint here. Needless to say, I didn't find R25 there either.

The Phase Linear 200 series 2 service manual (#1078) step 6.5.1 states: "Verify approx 0.4 VDC, +/-0.1V. Adjust bias pot R24 as necessary".

Perhaps you have a newer revision of one of the service manuals that I don't have that mentions R25 somewhere that isn't the service bulletin I mentioned previously. I'd like to know where my eyes failed me because this drove me nuts!



Thanks!
Ed

 

[oldphaser]

Yep, went through 2 manuals to figure out that R25 was the place to be.

I just bought a beat up series II and she is BEAT... But for $25 plus shipping, I figured WTF??? Besides, I'm going to use the Series II boards in this 200 and I'll compare the test results (After I rebuild the boards when it gets here). I needed a set of boards on hand anyway in case I build up the schematic in CAD. You have to have a set of boards in front of you to compare to the schematic. The last project I did had a few errors so I had to put it on the back burner till I found a set.


As far as the sockets, let me know if you figure out where to get them (or if you have a stash of them). If I gin up some boards maybe I can trade you some sockets for a pair of free boards???

The availability of these sockets will tell me if the project will be worth it.

Perry,

I just went through my boxes and found the bag of TO-3 sockets. It appears that I have (24) in total. Enough to do (3) amplifiers. I would gladly trade them for (4) PL19 series 2 pc boards that you have made. If possible, I would like the boards to match up with Phase Linear's original design without any modifications.

Ed

 

[orange]

See? It's got my name on it!

 

[THD+N]

All the transistors were dumped and replaced. It may have an impact as to how the amp performs and acts. MAYBE the design sux too bad to do anything about.

The design of the 200 is very similar to the 400/700 design. The only difference being the 200 is a Darlington output stage or emitter follower (EF2) output stage. The 400/700 is a triple emitter follower output stage (EF3). Technically, the EF2 should be more stable, but various design choices can affect that outcome.

The 200 should have the same "sound signature" as the 400/700 design, but at a lower power level. The LF356 could be replaced with a LF351 too.

What did you use to replace the RCA IC12/13?

 

[laatsch55]

Not a bad plan...

 

[orange]

So who bought it? How much?

 

[oldphaser]

https://www.ebay.com/itm/392076539436

$285

 

[orange]

It would've taken me two payments anyway, you did good Perry. I'm getting the bikes done for my niece and other nephew this month. Remember that deluxe 1995 Schwinn springer frame? I finished sending for the complete fenders, tank and correct chainring to make it look as close as possible to a Black Phantom.

Still wouldn't mind having a 200, the wattage is fine for this place.

 

[oldphaser]

Ya know Ed, you came in and opened your know-it-all yap and knocked my amp as being junk. I, in a polite way asked you keep your yap shut, and you keep running it. If you jump into one of my threads again uninvited and run you fucking mouth, I will hurt you. Stay away

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