Phase Linear 2000 troubleshooting

[Coldsmoke]

Hello there,

I am opening a new thread for the other problem I face with my system.
My PL2000 has the following issues :

- Poor channels separation : I followed the service manual and adjusted and cleaned all the inputs / outputs jacks.
- No ambiance : the manual suggests a replacement of Z2 (4739) an Q1 (GES97)
- Tone control malfunction : replace Z3 (4136)
- Noise in phono circuitry : replace Z1 (4739)
- Plops when turn on and off : place the necessary caps

I read a couple of threads about opamps upgrade here and there but I'm not sure where I can find these... (I mean the right opamps...)

Thanking you in advance,

 

[laatsch55]

There is no replacement for the 4739's. There is a "Browndog" adapter for the 4136 consisting of a DIP with OPA 2134 surface mount op-amps on it. Google "Browndog Adapters".

 

[Coldsmoke]

There is no replacement for the 4739's. There is a "Browndog" adapter for the 4136 consisting of a DIP with OPA 2134 surface mount op-amps on it. Google "Browndog Adapters".

Sorry Lee, I think I wasn't clear enough, my point was : where can I find this replacement chip? I think I read that it was possible to get it soldered from the net...
Same for the GES97, I do no not really trust the websites giving equivalencies for transistors...

 

[Coldsmoke]

There is no replacement for the 4739's. There is a "Browndog" adapter for the 4136 consisting of a DIP with OPA 2134 surface mount op-amps on it. Google "Browndog Adapters".

Hum... Excuse me again, but if my 4739's are dead, does this mean that I can throw my beloved 2000 away...???

 

[Coldsmoke]

Sorry Lee, I think I wasn't clear enough, my point was : where can I find this replacement chip? I think I read that it was possible to get it soldered from the net...
Same for the GES97, I do no not really trust the websites giving equivalencies for transistors...

Ok, I think I found where to buy it mounted.... but the 4739's..???

 

[gadget73]

Is it the op-amp that is bad? Leaky caps make noises too. This one is old enough where bad passives are very possible. I'd be checking that stuff before replacing op-amps.

 

[Coldsmoke]

Is it the op-amp that is bad? Leaky caps make noises too. This one is old enough where bad passives are very possible. I'd be checking that stuff before replacing op-amps.

HEllo and thanks Gadget.
All the electrolytics have been replaced by audio-grade components by the previous owner.

 

[Coldsmoke]

Would OPA2111AM be an option?

 

[laatsch55]

Would OPA2111AM be an option?

I've only used the 2134's, I have some 4739's (used) , if you need some...

 

[Coldsmoke]

I've only used the 2134's, I have some 4739's (used) , if you need some...

It's very kind of you Lee, but I suppose that if 2134 is good enough for you, it will be for me. But I was talking about OPA2111AM as a replacement for the 4739's
About the GES97, does it has a direct equivalent?

 

[laatsch55]

TIS-97 fairchild, I have a few thousand of those too....

 

[laatsch55]

It's very kind of you Lee, but I suppose that if 2134 is good enough for you, it will be for me. But I was talking about OPA2111AM as a replacement for the 4739's
About the GES97, does it has a direct equivalent?

The 4739's are a very weird duck. I have tried quite a few in it's place and they always oscillate. Joe tells me it has something to do with bandwidth and phase angles. We were going to rework the circuit on a 2000 to accept a different op-amp one of these days but so far have not done it...

 

[Coldsmoke]

Would you sell me a couple of 4739's and maybe a 97 or two?
I'd love to bring this thing back to life...

 

[Coldsmoke]

The 4739's are a very weird duck. I have tried quite a few in it's place and they always oscillate. Joe tells me it has something to do with bandwidth and phase angles. We were going to rework the circuit on a 2000 to accept a different op-amp one of these days but so far have not done it...

I would love to WOPL my 2000 too

 

[laatsch55]

Would you sell me a couple of 4739's and maybe a 97 or two?
I'd love to bring this thing back to life...

I certainly would. I would also suggest ordering some sockets for the Op-amps...

 

[Coldsmoke]

I certainly would. I would also suggest ordering some sockets for the Op-amps...

Certainly. If you think about anything else that you have in stock and that would be usefull for the restoration of the preamp, do not hesitate.
If you have a paypal account, name your price in PM and I'll transfer you the money right away.

 

[Coldsmoke]

Or for my WOPL 400, I'm considering installing a DC protection (or fuses but I can't find any proper socket)

 

[laatsch55]

Need a DC protect board too??

 

[Coldsmoke]

Need a DC protect board too??

I think I understood that it was a wise precaution, and I read here and there that fusing the cables could alterate the signal (If I could have figured how to mount these fuses I would have give it a try...)

 

[laatsch55]

I have a few 400 DC protect boards. Was just going to put one together for BubbaH's 400, I'll build 2.