Cgs synth

>The notes on Ken's site mention that the Rev1 cct had the resonance
>pot wired for 'bandwidth' and the Rev2 is altered to give resonance
>adjustment. I'd like to try wiring a board with the pot for
>bandwidth. Is this a question of swapping over the links on the board
>to the pot, i.e. swap the outer connections over or is the track
>different to/from the pot?

Simply a case of swapping the outer wires. It was not a true bandwidth
function, instead just labelled so due to the apparent change of bandwidth
when adjusting the resonance.

>Perhaps it's better to ask, can it be wired so the bandwidth can be
>adjusted and keep the resonance damped in any way? Some one suggested
>to me that changing the 6K8 would help to achieve this, any thoughts?

put a single gang pot in series with one of the 100k stages (one will be
backwards from what you want), or use two separate 100k pots instead.

>Also looked at the difference between Reverse Audio Taper (Neg Log)
>pots and linear response for the frequency adjustment. The curves for
>the two types are very different, how percievable is the difference
>and is it worth going the extra mile to track down these elusive
>pots?

not in my oppinion, no.

>Ken shows the cascaded filters wired to the DC mixer cct and I'd like
>to know if you could put a pot between the filter and input to the
>mixer - the other inputs if used show a 50K pot at their inputs (for
>attenuation/gain I figure?). Is it worthwhile to have one from the
>filter if you're using them on other inputs? Or would it be
>better/possible to link the cascaded filters to a socket and patch
>this into the mixer, treating them as discrete modules?

The latter would be more versatile, but if you don't mind the cost of doing
a dedicated mixer for the filters, it would be easier to use. Wire the pots
as per the DC mixer diagram.

>finally (fer now) would there be any benefit in using neg log pots
>for the 50K pots on the mixer inputs (I ask because, looking into the
>neg log thing, they seemed to use them in old equipment for volume
>pots) and shielded wire through the filter boards (tinned copper bus
>wire's the given) and to the mixer to cut down on interferance or is
>that *pointless/undoable/over the top (*delete as applicable)

no. In this case regular log would be more appropriate.



Ken
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Ken Stone sasami@... or sasami@...
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