[sdiy] Help with Buchla repair

[Oren Leavitt]

Nice catch there, Paul!

As for the part #s:
In a 1971 Fairchild linear data book, I have a uA749 dual op amp for the 
7749393 (U6A7749393)
I don't see anything on the U6A7005 number.
The '393' part of the # corresponds to a 0'C to +70'C electrical 
characteristics grade.
The 'U6A' part is the package type - in this case a 14 pin DIP.

HTH,
Oren

Paul Schreiber wrote:

>OK, I have this Buchla 200 boat anchor:
>
>www.synthtech.com/pix/buchla
>
>dead as a doornail. Thought I'd start with the 295 and 295 Comb Filters. Well, the 294 4-band is
>NOT AT ALL the same circuits as the 294 10-band one.
>
>Looking at the 294: has 4 14pin Fairchild ICs marked:
>
>7749393
>U6A7005
>
>Well, I can say with all confidence they are not LM393s made with date code 7749. I think
>building an audio comb filter from a dual comparator would be quite tricky :)
>
>Also: the 10-band uses a ton of parts marked LM341H (H = metal can). However, this is NOT a
>National voltage regulator (even harder to make comb filter from a voltage regulator than a
>comparator). The logo, if my ailing memory serves, is a Teledyne.
>
>I guessing this is so "fast" op amp. The date code is 7316.
>
>Any schematics/help appreciated. I'm sure I'll have tons more as I probe deeper (this is my
>little MOTM 'vacation').
>
>Paul S.
>
>
>  
>

-- 
Oren Leavitt
oleavitt at ix.netcom.com