Infinity 2000A rebuild

mjalazard

Well-Known Member
Well Kids, I'm at it again...
I found a pair of fully working 2000A that need some NFS Audio love.
As with my WTLC rebuild:
http://www.audiokarma.org/forums/showthread.php?t=487987
and the Quantum B's:
http://www.audiokarma.org/forums/showthread.php?t=552896
I have taken the plunge into electrostatics.
I plan to re-wire the crossovers, install new inductors and capacitors.
The tweeter circuit has a lot of resistors.
IMG_2863-X2.jpg

Any opinions on replacing these resistors, considering they are from 1971?
IMG_2855-X2.jpg

IMG_2875-X2.jpg

I'll take apart and clean the L-pads and use contact cleaner to get rid of the rust on the transformers.
But first, I'm working on the cabinets: crossbracing
IMG_2879-X2.jpg

Sound-coat:
IMG_2882-X2.jpg

IMG_2885-X2.jpg

Painting the front and back panels:
IMG_2886-X2.jpg

IMG_2889-X2.jpg

IMG_2890-X2.jpg


If I can find it, I have some black grill cloth to re-do those.
More photos to come.
Mike
 
I spent a little $$$ and put in some big Dayton poly caps in mine.
I believe those resistors are diodes.
Lately I've been tempted to install an extra pair of Watkins and Q4 xovers for kicks and giggles.
Have Fun!
 
I spent a little $$$ and put in some big Dayton poly caps in mine.
I believe those resistors are diodes.
Lately I've been tempted to install an extra pair of Watkins and Q4 xovers for kicks and giggles.
Have Fun!

I have ordered the Dayton caps and Mills resistors.
I am wondering about the the small resistors in series with the electrostatic tweeters.
IMG_2916-X3.jpg

Should I replace these?
I believe they are 22 MEG resisitors.
Here is the cabinet work:
IMG_2902-X2.jpg

IMG_2910-X2.jpg

IMG_2911-X2.jpg

IMG_2907-X2.jpg


I also reinforced and re-painted the stands:
IMG_2894-X2.jpg


Just a few coats of clearcoat, then it is on to the crossover!
Mike
 
I am wondering about the the small resistors in series with the electrostatic tweeters.

Probably a series of charging resistors to moderate the high polarization charge on the diaphragm. As I'm sure you know, the diaphragm is charged to a very high voltage.

Pick up a copy of Roger Sanders' book, The Electrostatic Loudspeaker Design Cookbook, for a full explanation.

G~
 
There are four 22Meg resistors in series on the high voltage polarizing line inside the box, and one 22Meg resistor at each tweeter. They are carbon composition, and have likely drifted way out of spec by now. They should be replaced with metal film types.

Did you finish this project?
 
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