uA726 replacement, (the comedy of errors)

[Grant Richter]

The Serge NTO really is a splendid design. The VCO section is the same
as the "Precision VCO" with an additional voltage controlled waveshaper
board. The problem is that the high Rbe of the 3046 mean that Serge
may use a more elaborate high frequency compensation scheme
than a simple resistor in series with the timing cap? I have repaired
a number of these but never bothered to trace out the circuit.
They really do work well, but are extremely sensitive to the power
supply stability and if you reverse the power supplies, they seem
to blow out every chip on the board.

----------
> From: Sean Costello <costello at seanet.com>
> To: >>>marjan<<< <urekar.m at EUnet.yu>
> Cc: Synth-DIY list <synth-diy at mailhost.bpa.nl>
> Subject: Re: uA726 replacement, (the comedy of errors)
> Date: Monday, August 16, 1999 11:39 AM
> 
> >>>marjan<<< wrote:
>  
> > Probably only one here who doesn't know, but what is Serge NTO?
> > (I've seen an-299 but not this schematic)
> 
> Serge New Timbral Oscillator. Not really "new," since it came out in the
late
> 1970's or so. It apparently uses a heated 3046 as the exponential
convertor. I
> have never seen a schematic (it does not appear to be one of the
schematics that
> is in general circulation). Serge has some pretty nice claims for this
circuit,
> but from what other people are saying, it may not be the best solution.
> 
> Sean Costello