Sunday, 24 February 2019

russia - Moscow 1 - some old pics

These date from 1998.. 20 years ago.
Lots of great memories. I hope to be returning to Russia soon.


A pic from my old travel journal.


 aRT by Moscow river

Behind Red Square

 Church in Red square

Dangerous lift ??


GUM department store

 Inside Kremlin

 Inside Kremlin
 Inside Kremlin
 Inside Kremlin

Inside Kremlin






For more travel postcards click here:

291r - build pics

some pics of a Buchla format 291r...

The old Rev 1 291r used 2 PCBs.
These aren't official build notes, just pics to help trouble shooting the build.


The cost of parts when building a 291 is very much tied up with the vactrols.
I'm using NOS VTL5C3/2. These average $20AUD each. There are chinese clones out there but I haven't used them yet. I think its better to use the original VTLs for this filter. if you can find them..


"The VTL5C3 (and VTL5C3/2) is what I refer to as the 'golden' Vactrol because of its response characteristics - I.E., the curve of its response when transitioning from dark to light and light to dark resistance. This curve, I believe through sheer serendipity, closely mimics the percussive envelope of certain natural objects. This response molds sharp transients into very 'organic' type responses. The response can range from a malleting sound, a 'thwipping' sound, or a plucking sound, depending on what's going on at the time. Interestingly, this response adapts to how *hard* or *soft* the transient is (in terms of amplitude) just as a natural object such as a string or drumhead would react when being plucked or struck softly or with more intensity." Scott Stites









This first build of mine was partly successful. I experimented with different pots on the upper and lower filters. The upper filter was most successful.

 I've seen a few suggestions:
Pot 1. Resonance Q: = 5K .... trim pot
Pot 3. Bandwidth Input:=  10K (Lin)
Pot 5. B.W. (CV) = 10K
Pot 2: FM: = 50K Lin
Pot 6. C.F. (CV) = 10K
Pot 4. Centre Freq = A10K

------------------------------------------------
I purchased  this 291r a while back which sounded great.

It was unusual as the pot choices were different to what I've used before.










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Building v2 of the 291r filter.
The BOM says:






20K LIN POT1, POT7
9MM VERTICAL 652-PTV09A-4030UB203

10-100K LIN POT3, POT4, POT5, POT6, POT9, POT10, POT11, POT12
16MM ANGLED
http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-16mm-right-angle-pc-mount/

10-100K AUDIO POT2, POT8
16MM ANGLED
http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-16mm-right-angle-pc-mount/

decided to stick with the  20K for the pot 1 & pot 7
and now use 100K A for pots  2 & 8 - (FM input).

we sill see how this sounds.













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