LuDEF

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The matching speakers :rofl:
 
status of ludef

This took way too long but here are the current boards status. It should be all downhill from here, as soon as I get the Cinemags. Got the prescribed special IRFP9140 from NJ since they are all out everywhere.

The PCB are well laid out and great quality. They come with the difficult bits pre-installed. I put the best components I could find hopefully be rewarded with amazing sound worthy of ZM & papa of course.
I m using the outboard LU boards from the group buy so that should be easy going.
I plan to swap out the M2x, put this into service and make go up against the final boss, the Vfet. 😀
 

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I used this procedure:

Short IN+ to Gnd

Take off Jumper JP101
Power On

P101 - Adjust for 20mv across R106
P102 - Measure DC Volts from JP101 pin 1 to Gnd - Adjust for 0 volts.

Replace Jumper JP101
P103 - Measure DC Volts from OUT+ Terminal to Gnd - Adjust for 0 volts

P104 - Adjust for 165mV across R129
P105 - Measure DC Volts between Source Pin of M103 and Source pin of M102
Adjust for 2V4 Volts
 
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as I'm not mounting my LUDEF boards on an L- or T-girder, and the LU-daughterboards from the groupbuy had the solderpads far south I had to use some short wires with heat resistant isolation and little brass standoffs.
tip: use an old flatiron semiheat as hotplate upsidedown in a benchvice
check temperature with solder (should NOT flow)
now put daughterboard on hotplate and solder everything easyly with your standard soldering-iron.
cheers
A.
 

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