[sdiy] Wikipedia DCO article

[Bob Weigel]

I never got to mess with the bit 01 or 99.  And I never totally got into 
what they did on the crumar Bit One but it's a bit of a pain to get it 
tuned :-).  It's got four interactive controls; 2/dco as I recall and I 
couldn't find instructions so I just messed with them until I got it..  
When you get it tuned in it can sure sound great on a lot of sound 
types.  Pads and bell like sounds and some brass are pretty noteworthy 
on that thing.  The Kawai SX240 has some of the best strings I think for 
a DCO machine but the sx series are good for some ethereal sounds with 
the portamento and organs.   The Poly61 is good for some weird Jarre 
type sounds, poly 800 for organs and ethereal bell type sounds...and the 
AX80 is the brash cyber-machine and good for some ethereal kinds of 
sounds, clavs... as is the DK600 but it excels at the brassy pads and is 
by far I think the most unique sounding of anything with DCO on it; 
probably because of the way the waveforms are produced mixed with 
otherwise 100% analog circuitry...plus the two independent oscillators 
at least to create some natural drift.

Simon Brouwer wrote:

>Bob Weigel schreef:
>  
>
>>Oh I see what you mean.  Yea I was thinking of the latter synths there
>>and I did gramatically group them.  I was thinking people probably
>>associated a *type* of synth with 'Juno' and I was noting how this new
>>series appeared the same year and THESE had the cpu driven
>>waveforms...I'll make it more clear.  The MKS30 and JX3P are timer as I
>>recall along with the SX Kawai's, the Bit series and..maybe the poly61
>>too...can't recall.
>>    
>>
>
>The bit 99 DCO's used two 74LS monostable multivibrator based high
>frequency oscillators, divided down by 8253's. These were followed by
>4-step binary counters whose outputs were summed using resistor networks
>to make a crude sawtooth.
>
>The drawbacks of this approach were it sounded a bit bland (especially at
>low pitches) and that you couldn't have PWM.
>
>  
>