Mark goes at it again... just bought a PL700/II!

MarkWComer said:
Ordered the G1 driver circuit, so the E circuit will be inherited by the 400.
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So anyway...

Biased at .36, remained at that point for a good long time, pretty stable!

DC offset was zero! The minus sign flashed off and on on the left side, but no numbers came up.
Right side showed nothing.

Damn good driver circuit!
 
MarkWCoomer
AB4A4854-5228-4E67-A00A-3AD05D3C0273.jpeg
Couldn’t hold back any longer bro...
 
Hey Mark! I've been watching your videos on the 400. I just acquired a 400 series 1, never touched on the inside. I already ordered the dc speaker protection from Watts Abundant. I'll be doing the Cap upgrade in a few weeks. I have to finish my other project first(technics sl7) which I had to find a donor for. I've ran the amp lightly and actually quite impressed for the age of the internals never being touched. Good to see a post I can put a face to! Michael
 
Michael88 said:
Hey Mark! I've been watching your videos on the 400. I just acquired a 400 series 1, never touched on the inside. I already ordered the dc speaker protection from Watts Abundant. I'll be doing the Cap upgrade in a few weeks. I have to finish my other project first(technics sl7) which I had to find a donor for. I've ran the amp lightly and actually quite impressed for the age of the internals never being touched. Good to see a post I can put a face to! Michael
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Glad someone's watching! I bought a new camera, restarted the 700 project, so a string of videos to come when I get some steps done on that one.

THANKS!
 
So then... the copper bus...

When I did the 400 there was a single point ground protruding through the left channel backplane.

We don't do that on the 700s?

Everything I see so far says DC protection, GND_IN1 & 2, and output ground to speakers hang off the copper bus ground.
No "star" grounds on the 700?
 
MarkWComer said:
So then... the copper bus...

When I did the 400 there was a single point ground protruding through the left channel backplane.

We don't do that on the 700s?

Everything I see so far says DC protection, GND_IN1 & 2, and output ground to speakers hang off the copper bus ground.
No "star" grounds on the 700?
Click to expand...

Full star ground. I have to ask you what is leading you to that conclusion Mark. Same as the 400. The center of the star is always the copper bus bar between the bulk caps.
 
Gepetto said:
Full star ground. I have to ask you what is leading you to that conclusion Mark. Same as the 400. The center of the star is always the copper bus bar between the bulk caps.
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My backplane documentation states GND_IN1 & 2 attach to copper bus, DC circuit states add a lug to the ground wire and attach to one of the screws attaching the copper bus to the filter cap, and haven’t found anything that clearly states that I’m attaching a lug to the stud protruding through the left backplane board.

Maybe I didn’t print something?
 
MarkWComer said:
My backplane documentation states GND_IN1 & 2 attach to copper bus, DC circuit states add a lug to the ground wire and attach to one of the screws attaching the copper bus to the filter cap, and haven’t found anything that clearly states that I’m attaching a lug to the stud protruding through the left backplane board.

Maybe I didn’t print something?
Click to expand...

41. Add ONE 20AWG white jumper wire from the single point ground (bus bar between the 2 bulk capacitors) to the UPPER 6-32 standoff stud that you installed in the previous steps. Terminate this wire in a #6 lug. Place the solder lug on top of the 6-32 screw protruding through the standoff and thread on and tighten a 6-32 hex nut. This one connection ties the chassis to the DC ground for the amplifier. It is important that there is only ONE such connection.

1583965991571.png
 
Gepetto said:
41. Add ONE 20AWG white jumper wire from the single point ground (bus bar between the 2 bulk capacitors) to the UPPER 6-32 standoff stud that you installed in the previous steps. Terminate this wire in a #6 lug. Place the solder lug on top of the 6-32 screw protruding through the standoff and thread on and tighten a 6-32 hex nut. This one connection ties the chassis to the DC ground for the amplifier. It is important that there is only ONE such connection.

View attachment 40402
Click to expand...
Yup... there it is... Found it in my binder where it should be, sorry about that...
The Watts Abundant doc details connection to the point-to-point chassis, but got that one, too.
 
MarkWComer said:
Glad someone's watching! I bought a new camera, restarted the 700 project, so a string of videos to come when I get some steps done on that one.

THANKS!
Click to expand...
Excellent! Waiting patiently for the new videos Mark, looking forward to the continuing adventures ahead. Thank you for doing them and the time you spend on them also.
 
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