PL700 Series II Lessons Learned

kwingylee

New Around These Parts
Joined
Sep 8, 2021
Messages
11
Location
Chicago, IL
#24
My first foray into a complete rebuild of a PL700 Series II was quite a learning experience, I have been a PL700B guy until now. This rebuild included a new chassis, 120V/240V selector switch, WOA Backplane Kits, WOA Control Board Kit, WOA Cylon LED Board Kits, WOA bulk capacitors, new power switch, and DC Protect Board including new input and output connectors.

I learned you can put a heatsink in upside down and the amp will still pass a bias test:
View attachment 43618

I learned not to test the temperature of the output devices with your hand if you touch two rows at a time:
View attachment 43619

I learned not to let my 250 Watt soldering iron get too close to the bulk capacitors:
View attachment 43620

But, I also learned that when I applied power for the first time, the initial bias value was 335mV and it was an easy adjust to get to 350mV, the DC offset was 0.000V, and the Cylon LEDs need the -100V reference (rail fuses uninstalled) or all the segments will light up very brightly:
View attachment 43621

Overall, the 80 hours of work on this amplifier were very satisfying. However, hearing some Shpongle at mach 10 made it even more satisfying. They call it "Burning in" but it is really the technician saying "Oh, yeah..."
Where did you sourced the power switch from?
 

FredR

Chief Journeyman
Joined
Jan 26, 2014
Messages
863
Location
DFW
Tagline
WTF?
#28
when i was about 12 years old I gave my sister insulated wire cutters and told her to cut a 110v wire at the wall socket. she is 4 years younger. hell of a spark show, but no harm. scared the shit out of her. Still feel guilty about that.
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
65,357
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#30
when i was about 12 years old I gave my sister insulated wire cutters and told her to cut a 110v wire at the wall socket. she is 4 years younger. hell of a spark show, but no harm. scared the shit out of her. Still feel guilty about that.
I had an older sister, i regret nothing..
 
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