PL 700 II Clair Bros Rising from the Ashes

Peter S

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Hi Folks;
How is everyone coping with covid? After 3 WOPL's, I have a number of pl909 outputs lying around. I am looking for a low dollar project and was thinking of reviving this old CS800. Would the old PL transistors be suitable for this amp?
 

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Gepetto

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Is the Peavey not working?

You have some Moto transistors and ON Semi transistors in the Peavey, many appear original. Moto made the best power semiconductors on the planet, bar none (now ON Semi which carries on that legacy).
 

Peter S

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Hi Joe;
Both channels have shorted outputs. When one channel died, they kept using it as a mono amp until the other channel died. One driver board has some issues. I thought it would be a good amp for backyard system; four Cerwin Vega cabinets with 18" LF's.
Would the pl909's be OK driving a 4 ohm load (lower B+ voltage)? I could ((Vbe ) match the pl909's if necessary, as they are from different amplifiers.
BTW, Thanks for the info re switching power supplies. There is some good info on wiki also.
 

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Peter S

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Possibly, it spent it's last few years in a practice studio in downtown Toronto. So it got a kind of protective layer of tar (and who knows what else). Those pics were taken after I blasted it with compressed air, outside.
The price was right; $25 Canadian, about $4.75 US!
 

FredR

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Possibly, it spent it's last few years in a practice studio in downtown Toronto. So it got a kind of protective layer of tar (and who knows what else). Those pics were taken after I blasted it with compressed air, outside.
The price was right; $25 Canadian, about $4.75 US!
The Loonie is worth more than that!
 

Peter S

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Good morning folks!
Just wondering if anyone has thoughts about re-using my old pl909 outputs transistors for a 'clunker' Peavey CS800 that I would like to revive for my backyard system?
Are they comparable to the MJ15024's? Does anyone have specs on these original transistors?
 

Peter S

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Thanks, Joe;
I guess I'm looking for some MJ21196's at some point. Have you replenished your stock?
Before I ordered from you last time, I thought I found a 'deal' from an over-seas supplier. They turned out to be fakes with the actual (silicon chip) inside being one quarter the size of the ---24's.
My first PL, an original PL700 went fins up in 1980. The repair shop just ordered 3 more pl909's from PhaseLinear ( probably ) and the amp is still running today. I hope to WOPL it at some point, but not bad eh? Would there not be some kind of consistency among all pl909's?
 

Gepetto

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HI Peter
I have stock and do my best to always keep it that way, getting harder to keep prices down though these days.

Ed had posted this on the PhaseTek site a long time ago. You can still get to some of his stuff through the way back machine. You can see they were not much by today's standards but at the time they were the few that could do the job.

xpl909.jpg
 

FredR

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95 and 96 seem to go out of stock more and more. And when they are in stock it is in smaller quantities.
 

Peter S

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Thanks, Joe;
Yikes! 3.5 amps compared to 16 amps Ic for the 96's. I guess that contributed to the Flame Linear issue...So tempting though, I hate to see all those pl909s going to waste, but the Peavey amp will be driving two 18" drivers per channel....so I guess I will 'bite the bullet' and spring for 96's if I can get the amp working (driver board issue)
 

Gepetto

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Thanks, Joe;
Yikes! 3.5 amps compared to 16 amps Ic for the 96's. I guess that contributed to the Flame Linear issue...So tempting though, I hate to see all those pl909s going to waste, but the Peavey amp will be driving two 18" drivers per channel....so I guess I will 'bite the bullet' and spring for 96's if I can get the amp working (driver board issue)
Yup, probably the best available when the PL series was born which is likely why they jumped to the 15024 when they emerged from Moto. Had they waited for better transistors to emerge, PL would have likely missed the window of opportunity. They did the right thing.
 
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