Wednesday 12 March 2014

191 Sharp Cutoff Filter - build notes

My Build notes for the LA191 filter.
It's not a Buchla Module.
It follows the same size & format & the circuits used are I understand based on Don's schematics.
I would love Buchla USA to make a official 191 filter.
Until that day, this will have to do.
 
These are not official build notes Just my personal pics to help trouble shoot.



The vintage Buchla 191 is a very rare filter. I'd love to see or purchase a real one.
Maybe Buchla USA will come out with one ... lets hope.

 Anyway, I'm building this for a friend.
The PCB (LA 67) looks great. An easy build I think.


aLL through hole.

Parts are standard .. all discrete.
Some of the transistors need to be matched.


The switch is a bit confusing.

My wiring guide

These pics are the top section (its upside down in the photo)


nOW it gets confusing ... the bottom bit




tHE heatshrink seemed like a good idea at the time, however, it later made my job harder as the hole the switch fits into was too small.
 
got it in ,,,, but was a real mess.
My apologies to the future techo who needs to service this.





 The "Lamps" are polarized.
THey  are actually LEDs  not incandesent lamps
(Incandescent Panel Mount Indicators Panel Mount Indicator Lamps)







A bit of a mess...
But the filter seems to work.
Anyway, I have no idea how this stacks up to a real 191.

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