Phase Linear 200 rebuild

[laatsch55]

Just one module per amp? As in both channels in one module?

 

[kl0neMan]

I already pulled the trigger on 4 of that very item (MJ21196) based upon an old chat I had lost and found today!!!! Great to hear independent confirmation of the correct choice. I bought 4 of the other part too - changing them all, along with the rectifier, and the ST258s.

With the modules out and power supply disassembled, I can verify the integrity of the power transformer, add the new rectifier and caps and check the power supply out before powering the modules.

Dan

 

[kl0neMan]

Just one module per amp? As in both channels in one module?

I’ll be doing both modules (2 of each device type in each module for a total of 8 devices.), even though the output transistors were not bad in the other module.

Dan

 

[laatsch55]

Hookay...

 

[kl0neMan]

Transformer appears to be okay, based upon unloaded tests using DBT. Almost no real current draw, and each output to CT showed the same AC Voltage. I now await the arrival of the replacements for the darlington pairs and the power rectifier before going further.

 

[laatsch55]

Coolness..

 

[kl0neMan]

I noticed that I had missed the contents of the second package from Mouser - The bridge and all the transistors 4 MJ21196G and 4 MJ15022G were in it. I installed the bridge, and connected it to the caps, but no amplifier modules. (there was also a second set of AC connections that feed a discrete diode bridge on the LED Meter Display board that I reconnected. Under this condition, the voltage across the caps is +69 and -69 with respect to Centertap, with maybe 1 mA of current drawn from mains (measured with a current loop provided by my DBT.)

Since this amp was previously worked on before I got it, I wanted to make sure the transistors are in the proper physical locations. My guess is that the MJ15022Gs go in the inner two locations (where 66430s are) and the MJ21196Gs go in the outer two locations (where the RCA410s are). Does this sound correct?

Dan

 

[laatsch55]

NO! The 21196's go where the 66430's are. The 15022's are just a lesser rated NPN part.

 

[kl0neMan]

>>
NO! The 21196's go where the 66430's are. The 15022's are just a lesser rated NPN part.
<<

Okay, and the MJ21196 are to be installed in the interior locations - I am trying to ensure none of these devices were swapped somehow before I got there.

Dan

 

[laatsch55]

The schematic will tell you that...you have a service manual?

 

[kl0neMan]

The schematic will tell you that...you have a service manual?

I have a schematic, but I do not pictorials of anything. I have a service manual, but I have read, in this forum I think, that it has errors too.

 

[laatsch55]

One of the errors would not entail drivers in the position of outputs and vice versa..

the 410's being drivers and the 66430's as outputs..

 

[kl0neMan]

NO! The 21196's go where the 66430's are. The 15022's are just a lesser rated NPN part.

I have annotated my schematic with the substituted part numbers. Now to find a pictorial. If not successful, I will trace the foil. Per my copy of the schematic, the MJ21196's emitters feed the MJ15022's, bases.

 

[laatsch55]

Can you post a pic of that?

 

[kl0neMan]

The Service Manual I have is for series II, not the original..

 

[kl0neMan]

Can you post a pic of that?

Attached is the annotated schematic. I also annotated the 2N3439s.

 

[laatsch55]

Where are the 410-'s shown?

 

[kl0neMan]

Where are the 410-'s shown?

They were originally those 66546's. In my unit they were RCA 410s. (never saw a 66546 in it) There were also the 66430's in it.

 

[kl0neMan]

Schematic to foil trace indicates the 21196's in the center, and 15022's on the outsides. The JAN2N3439 is Q3. I have annotated the schematic and reuploaded it to my prior post

 

[laatsch55]

Ok, from your schematic, the 66430's should be replaced with the 410's, the 66546 should be replaced with the 21196's..,.,