[sdiy] Wikipedia DCO article

[Tom Wiltshire]

On 13 Jan 2009, at 10:40, cheater cheater wrote:

> 8<---
> Confusion over terminology
>
> The term "digitally-controlled oscillator" has been used to describe
> the combination of a voltage-controlled oscillator driven by a control
> signal from a digital-to-analog converter, and is also sometimes used
> to describe numerically-controlled oscillators.
>
> This article refers specifically to the DCOs used in many synthesizers
> of the 1980's. These include the Roland Juno-60, Juno-106, JX-3P,
> JX-8P, and JX-10, the Korg Poly-61 and Poly 800, and some instruments
> by Akai and Kawai.
> 8<---
> This paragraph doesn't actually state which of these definitions is  
> correct.

I admit I was rather hoping to avoid that particular minefield.  
Instead I chose to just say what the article considers under the  
heading, and avoided whether other designs of DCO are properly called  
"DCO" or not.

Just for the record, I don't think a VCO driven from a DAC is a DCO  
(otherwise the Prophet 5 would be a DCO synth, which it isn't) and I  
don't think NCOs are DCOs either, since there is a different, more  
specific, term for those.

That still leaves quite a few designs in the middle ground (like the  
BIt 01) beyond the typical ramp-core-plus-reset-pulses DCO that I  
started out by describing.

T.

PS: Thanks for your work on this, Bob, and thanks for the comments  
everyone else.