[sdiy] SG3821 Transistor array

[John Henson]

Hi Terry and list,
I remember reading an interview with Dave Hemsath of Moog.
I cannot recall whether it was the text file on Analogue Heaven or the book 
Analog Days, but the gist is that the Moog engineers looked at the LM3046 as 
Expo converters but didn't think they were good enough. A company called 
Silicon General (sic) gave them samples of the SG3821 which in Bill's words 
were very tightly matched, and the Mark 2 Minimoog Oscillator board was the 
result.
I rebuilt a Mini with a serial number in the 1600's and it had the 2 
original SG3821's in it which is interesting as every other Mini I've worked 
on has had one of the 3046's replaced at some point.
The newer 3046's are probably far better than the early 70's versions and 
should be a quite adequate substitute.
Regards
John
----- Original Message ----- 
From: "thx1138" <thx1138 at earthlink.net>
To: "SDIY List" <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, September 10, 2009 5:49 PM
Subject: [sdiy] SG3821 Transistor array


> Hi SDIY folks.
>
> I am rebuilding the Universal Active Filter Module designed back in 1973.
>
> I am looking for a Data Sheet on the SG3821 Transistor array.
>
> It has been a long time singe I used this part and if anyone has a better
> replacement suggestion I would be interested in your comments.
>
> I was looking at the CA3046 and CA3086 devices and these type of parts.
>
> We used them at Oberheim for the SEM1-A for Osc. 1 & 2 designs.
>
> I just have not been able to get a data sheet on the SG3821. It would be
> nice to keep the same part in the design but I am afraid it may be hard to
> find these days.
>
> Regards,
>
> Terry
>
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