Gibsonian's Cherry Pl 700 Ser I, soon to be a PLWO-1000

That is not good Lee. Get those counterfeits out of there before they fail on you.
 
Funny, it always seems to be instrumentation that we are chasing problems in :-)
 
Joe, Phase was pretty adamant about the drivers being different trannies than the outputs. I've only seen one amp come through here that had both XPL's as drivers and XPL's as outputs. Don't know of anybody here who has tried that combo, unlike the 2SD 555 fiasco.
 
Spoke too soon on the Cathy problem, the screech is gone, so is the hum, now we have a "muffled" left channel...didn't notice till I cranked it..
 
It matters little on the upper half of the signal but it is critical on the lower half.
 
It must be the name Cathy. You have had your share of problems with her.
 
Most of them self imposed, slip of the probe, etc...
 
During the last slip of the probe the event wiped out all the emitter resistors on the minus drive on the left channel, hence the muffled sound. We're about 30 minutes from being done, stay tuned.

BTW, those .278 ohm resistors were measuring 247K, yep[.....
 
Sounds like the emitter resistors were doing their job until they got really hot, really fast...

Joe, are you talking about the negative-going portion of the frequency band? Could you explain that a bit more for those of us who were daydreaming in Electronic Theory 101.

Thanks.
 
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Hi Mark
I mean the negative half of the quasi complementary output, comprised of Q12, Q14, Q16 and Q18 on the PL400 schematic.
 
Took awhile but we are there, Cathy is getting stress tested right now. Lost the tweeter in the left horn. Gettin pretty radica;l./
 

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Not to hijack, but clear out you PMs, Lee, server says you've exceeded 1250?

Cannot PM you!
 
Sent an email and left voicemail on your cell.
 
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