[sdiy] Muse musings

[Tim Ressel]

Gene,

Oh, so that's what they meant by major scale
convertor! I think I'll just put a 2716 in front of
the DAC I have.

Or expand on it: use a 16-bit DAC and two eproms and
have multiple scales like just intoned etc.

--tr

--- Gene Stopp <gene at ixiacom.com> wrote:
> Question for Muse builders - did you make the major
> scale converter thingey
> also? If so, how did you do it? It's just another
> block in the block diagram
> in Hal's book.
> 
> Been musing on this lately - I can think of a few
> ways to do it, seems like
> a fun topic...
> 
> By "major scale converter" I mean a digital word-in
> word-out circuit which
> takes a binary count on the input side and produces
> a parallel output which
> is the binary numbers for a major scale if put into
> a linear DAC with 1/12
> volt output steps. Example:
> 
> Input   Output
> 0000    00000    C
> 0001    00010    D
> 0010    00100    E
> 0011    00101    F
> 0100    00111    G
> 0101    01001    A
> 0110    01011    B
> 0111    01101    C
> 1000    01110    D
> 1001    10000    E
> 1010    10001    F
> 1011    10011    G
> 1100    10101    A
> 1101    10111    B
> 1110    11000    C
> 1111    11010    D
> 
> etc.
> 
> One way to do this - look up table. Another way -
> diode matrix. Both seem
> pretty easy, except the lookup table may require an
> EPROM or similar thing.
> An advantage to the EPROM approach is that it would
> be easy to make
> alternate "pages" for different scale types (major,
> minor, etc.).
> 
> The diode matrix is very simple for a small number
> of bits (i.e. just a
> couple of octaves) but you could have a few bits for
> note select and then a
> couple more bits for octave select.
> 
> - Gene
> 
> 
> -----Original Message-----
> From: Gavin and Delia
> [mailto:elmystico at earthlink.net]
> Sent: Wednesday, July 02, 2003 3:40 PM
> To: Tim Ressel; Synth-Diy
> Subject: Re: [sdiy] Muse musings
> 
> 
> where is the original schematics for this project?
> ----------
> >From: Tim Ressel <madhun2001 at yahoo.com>
> >To: Synth-Diy <synth-diy at dropmix.xs4all.nl>
> >Subject: [sdiy] Muse musings
> >Date: Wed, Jul 2, 2003, 4:11 PM
> >
> 
> >Hey gang,
> >
> >A while ago I built the Muse out of the Chamberlin
> >book. It is a sequence generator consisting of a
> >divider chain and shift register driven off of a
> >variable clock. the input of the shift register has
> a
> >parity tree on it, the inputs of which can be
> >connected to any og the shifter of counter outputs.
> My
> >version so far has only an 8-bit DAC for an output.
> >The DAC inputs can connect to any of the outputs.
> >
> >I've been looking to expand it, and I think I know
> >how: The good ol' DG408. 8-to-1 mux with TTL
> inputs. A
> >few of those along with a set of jacks with note
> >voltages on them will make a nifty little bugger.
> >It'll do sequences or random notes from a list you
> >choose. 
> >
> >Groovy, eh?
> >
> >--tr
> >
> >
> >
> >
> >__________________________________
> >Do you Yahoo!?
> >SBC Yahoo! DSL - Now only $29.95 per month!
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