Roland System 100m

Hello

The ua726 is the dual matched transistor for the control voltage
exponential converter.
This does not affect the sound per se, more the tracking and stability
of the VCO's pitch.
They contain a "heater" to keep the transistors at a constant temperature.

They are pretty rare, but you can buy them on Ebay from
"hongkongsuperseller" or "allpartspipe".

-ryk



--- In RolandSystem100m@yahoogroups.com, David Bulog <d2ba@...> wrote:
>
> Thanks very much guys so getting back to my question on VCO's are   
> uA726HC chips an off the shelf part
> thanks David
> 
> Like most Roland synths from the 70's they use uA726HC-based VCO's. I
> believe all "Systems" and all SH's less than 100 uses them as well as
> Jupiter-4, Promars. and SPV-355.
> On 20/04/2008, at 9:19 PM, synth ollie wrote:
> 
> >
> > ooops sorry, my mistake !
> >
> > I was (almost) certain that sh2 and 09 had the same
> > vcf design as system100 - transistors and not ba622
> >
> > but I just checked the sh09 schemo and I can see that it uses
> > the ba622 just as you say
> >
> > (I should have red the schemos before I opened my mouth ;c) )
> >
> > ________________________________
> >
> > To: RolandSystem100m@yahoogroups.com
> > From: synth@...
> > Date: Sun, 20 Apr 2008 18:06:39 +0900
> > Subject: Re: [RolandSystem100m] Roland SH2 VCO question
> >
> > The SH2 does sound similar to the SH09/100M.
> > They all use the same OTA filter based on BA662 chips.
> > This design comes from the System700 OTA filter based on CA3080 chips.
> > You can find the same filter as the 700's in the SH1 only.
> > The System100 has a different filter design as it uses a transistor  
> > filter like the SH5.
> > Roland eventually came back to a transistor filter with...the TB303.
> >
> > Cheers
> > Olivier
> > P.S: hope my English is clear enough.
> >
> > David Bulog wrote:
> >
> > Hi does anyone on the list know if SH2 or SH09 uses a custom IC for
> > each of the VCOs or is discrete off the self components like System
> > 100 101
> >
> > My other question is would the SH2 be similar in sound to a System
> > 100m three module combo consisting of 112,130,140.
> > The SH-2 is the only Dual VCO Roland apart from SH5/7 that is still
> > reasonably priced
> >
> > thanks in advance
> > David
> >
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>