Phase Linear 200 repair

iSteedman

iSteedman

New Member
I inherited a Phase Linear Model 200 from my father some years ago. It had just been sitting in his attic not being used. I found that it has an issue in the right (B) channel. after it warms up and at random intervals a loud static will be heard in that channel. The static can be dissipated by removing the positive output for that channel and taping it back on few times, then putting it back in. It will continue or re-occur as long as you are using the amp.
The amp does show evidence of repair in the past, mostly the left (A) channel has a a few transistors and capacitors replaced.
I am no electrical engineer, but I'm comfortable with replacing components. I just have no idea where to start.
 
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Apologies for not introducing myself before asking for help. My name is Ian, I just turned 31 back in October and my wife and I had our first child (William) in September. I really like playing music throughout the house and have started a small Sonos setup with a couple Play:1. They are adequate for background music, but I am looking to setup my family room to have a better music experience. The Phase Linear 200 will drive a pair of JBL L26 that I just re-foamed the woofers in. They sound great, just scare the crap out of me when the static occurs (really loud).

Also, after more reading I would describe the sound as popping at times, appears this would point to a faulty transistor? Do i have to remove them for testing? they are all over the card.

Thanks in advance for any help.
 
iSteedman said:
I inherited a Phase Linear Model 200 from my father some years ago. It had just been sitting in his attic not being used. I found that it has an issue in the right (B) channel. after it warms up and at random intervals a loud static will be heard in that channel. The static can be dissipated by removing the positive output for that channel and taping it back on few times, then putting it back in. It will continue or re-occur as long as you are using the amp.
The amp does show evidence of repair in the past, mostly the left (A) channel has a a few transistors and capacitors replaced.
I am no electrical engineer, but I'm comfortable with replacing components. I just have no idea where to start.
Click to expand...

First off, assuming you are able to read schematics, if you don't have one it would be a good idea to snag a service manual.
https://www.hifiengine.com/manual_library/phase-linear/200.shtml

A place to start would be to clean the speaker protection relay. Do "not" use anything abrasive such as sandpaper.
Normally I don't recommend solvents like WD40, to be anywhere near audio equipment. But for cleaning a set of relay contacts it's OK if you don't have DeOxit. Take heavy paper or a very thin piece of cardboard and soak it with a the solvent. Then slip the paper between the contacts. Put very slight pressure on the contact set as though you were trying to engage them manually.Then "pull" the paper "straight" through the contact set.
 

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Hello iSteedman. Welcome to AK. Some transistors can be noisy or go bad check here,http://www.audiokarma.org/forums/in...ilure-prone-whatever-and-replacements.731653/. Compare what is in the amp against the SM. Then see if any of them match against the thread, depending on the noise you are having from the amp. It is one way to check. Also look for bad solder connections, caps. It is a start. As for cleaning switches, pots, see the "Idiots guide to using DeOxit" in the General Audio Discussion forum. Would apply to a lot of electronics cleaners.
 
Join the Phoenix Audio Forum, it's the home of all things Phase Linear. Most of the members there are also members here. Is this a 200, 200B or 200 series II? Does yours have LED meter display or a plain face plate?
 
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Thanks for the suggestions, Ill hopefully have more time to open it up again later this week. Where is a good place to get capacitors for replacement?


Northwinds said:
Join the Phoenix Audio Forum, it's the home of all things Phase Linear. Most of the members there are also members here. Is this a 200, 200B or 200 series II? Does yours have LED meter display or a plain face plate?
Click to expand...

not sure on the exact model, I'm pretty sure it is not the series II though. It has the LED meter display.
 
20180626_223304.jpg Ive got the model 200 does the lights come on when you plug it in? No power switch? Im clueless right now i just picked it up today
 
Dropthatbass said:
View attachment 1221552 Ive got the model 200 does the lights come on when you plug it in? No power switch? Im clueless right now i just picked it up today
Click to expand...

You should start your own thread.

Burned out lamps are common and I’ve heard those tend to usually be out.

For some odd reason, in all the tons of gear that have gone through here, I have never had Phase Linear. And for all the stuff I’ve worked on, only one weird duck 700 went through that could not be worked on. It was a one of, Bob Carver special. Maybe even a prototype.

Anyway,

Many power amps don’t have a power switch.
The ran off the switched outlet on the preamp.
 
iSteedman said:
I inherited a Phase Linear Model 200 from my father some years ago. It had just been sitting in his attic not being used. I found that it has an issue in the right (B) channel. after it warms up and at random intervals a loud static will be heard in that channel. The static can be dissipated by removing the positive output for that channel and taping it back on few times, then putting it back in. It will continue or re-occur as long as you are using the amp.
The amp does show evidence of repair in the past, mostly the left (A) channel has a a few transistors and capacitors replaced.
I am no electrical engineer, but I'm comfortable with replacing components. I just have no idea where to start.
Click to expand...
good morning from Italy.....could I know the voltage that powers the LEDs in PL200thanks Egidio
 
ivandezande said:
That member has not been seen since Dec 11, 2017.
Why don't you look at the service manual?
Click to expand...
there is no service for the PL 200 first series, only the electrical diagram, but the voltage of the LEDs is not highlighted... considering the drop resistance, I think it is around 18/20 volts
 
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