[sdiy] 8038 XR2206

[Tom Bugs]

Hiya

Many details would, I reckon, be covered by the recent Thomas Henry VCO 
Chip Handbook published by the great sMs Electronics (State Machine on 
Electro-music)

There's a few other implementations of 566 oscs doted around online 
too.. I think all TH's designs use this Gnd/-15v supply method - seemed 
like a strange arrangement to me at first, but if it works good.......

I've got a compact pcb plan for TH's 2206 VCO on my site. I don't use 
the sin/tri switch so often, but the wonderful feature of the VCO is the 
VC Skew function - this inverts half of the sin or tri wave, giving 
great harmonic results:
http://mypeoplepc.com/members/scottnoanh/birthofasynth/id20.html

Bestbest,
Tom

dj hohum wrote:
> On 7/11/07, John Mahoney <jmahoney at gate.net> wrote:
>> At 11:44 PM 7/11/2007, dj hohum wrote:
>>
>> >Rummaging through my junkbox I was sure I had a 566 or two. Well, I
>> >have 555, 556,565, and 567, but no 566. My memory is telling me this
>> >isn't the first time that this has happened.
>>
>> People mix up the 556 (dual 555) and the rare 566 all the time.
>
> Yeah,well at some point in time (like in the past 20 years), I had at
> least one or two 566 chips. But, I think that they're long gone and I
> just keep relooking for them thinking that I saw them someplace.
>
>> >But, I do have a pair of 8038s, one with a 1.79 price tag from the
>> >shack!, and a pair of XR-2206s. Looking at the schematics for the
>> >thomas henry VCO here:
>> >
>> >http://electro-music.com/forum/phpbb-files/schem2_161.jpg
>> >
>> >It seems that there's no positive power connection? Is this correct?
>>
>> Yes! The chip runs in reverse. ;-)  Seriously, the power connections
>> are Ground and V- instead of V+ and Ground. Thomas credits this
>> discovery to John Simonton (originally with the 566, I think).
>
> So are the outputs centered across zero? Or, are they negative going?
>
> tnx,
> Daryl
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>