700B serie 1 faulty

[WOPL Sniffer]

Is there many 700b on the forum ???

Yes, and the number grows daily.

 

[derek92994]

The love must be shared. WOPL THE WORLD!! (WTW)

 

[66stanger]

Is there many 700b on the forum ???

Yes, and the number grows daily.

So, OnSemi is happy...

 

[laatsch55]

Need a pic of the back of your amp. If it's quasi comp the bottom row of transistors is different than the rest...

 

[WOPL Sniffer]

So, OnSemi is happy...

I don't know about "OnSemi" being happy but anybody who has gotten their hand on a WOPL sure the hell is....

 

[66stanger]

Need a pic of the back of your amp. If it's quasi comp the bottom row of transistors is different than the rest...

Here is the pic, before replacement... :

 

[66stanger]

Here is the pic, before replacement... :
View attachment 22244

With a better pic... :-/



And after :



Following this one found in the web... :


Find the mistake...

 

[laatsch55]

Did replacing the outputs cure the problem?

 

[66stanger]

Did replacing the outputs cure the problem?

I would like to be sure before turn on...

 

[Gepetto]

I would like to be sure before turn on...

Well if unsure, you should only populate the bottom row. If you do not know if it works, powering up with all transistors in could be a very expensive trial and error experiment.

The amp will work with only the bottom row in it for test bring-up purposes.

 

[66stanger]

Well if unsure, you should only populate the bottom row. If you do not know if it works, powering up with all transistors in could be a very expensive trial and error experiment.

The amp will work with only the bottom row in it for test bring-up purposes.

Of course, it will be a very expensive error...
But I need to know which transistor posistion is correct regarding pic of the thread... :-/

 

[Gepetto]

Of course, it will be a very expensive error...
But I need to know which transistor posistion is correct regarding pic of the thread... :-/

In a quasi comp amp such as yours, bottom row is RCA410 in each of the 4 columns


That row is sufficient for initial bring up.

Each row above that should be MJ21196 if you are planning to upgrade your output transistor devices from the original PL909 transistors that Phase Linear used.

 

[66stanger]

Gepetto,

Sorry for my poor English or for my bad explanation, but the pics below (1 & 2) are those of my Phase.
And the third is from the Web.
The last one is correct ?

I know the row but I not the position (rotation).
I found the 3) and I checked the Serial Number, it's the same serie of mine.

I've replaced the Driver board from Joe and output trans. also.
Before to fire up I prefer to be sure of the marker position...


1)
View attachment 22249

And after :
2)

View attachment 22250

3) Following this one found in the web... :
View attachment 22251


Thanks