[sdiy] voltage controlled filter???

[synthplayer88 at spymac.com]

So I guess, when it comes to VCF it doesnt really make any difference what
multiplier you use in terms of the performance? Except the CV are exp on THAT
chips and linear on multipliers? Wonder if it will sound better with THAT chips? :)

On the data sheet of some of the multipliers the specs looks pretty good
especially in BW way up to Mhz but I guess it doesnt mean anything for audio
applications.... the dynamic range is pretty good too but they cost like $30
USD!!!! Some of the AD and TI multiplier chips......



On Wed Jan  5  6:09 , Steve Ridley <spr at spridley.freeserve.co.uk> sent:

>
>> BTW, using multipliers for VCA seems to be the most common method 
>> in synth has anyone tried other VCAs such as from THAT corp the 2180 
>> series or National CLC520 or AD SSM2164, SSM2018, MLT04, AD734, 
>> AD835, AD633 or TI VCA810, 4214, 4213, MPY100, MPY634 or 
>> ON MC1496P etc......
>
>2180s (or the earlier 2150s) have been seen in several professional
>mixing desk EQs.  They have an exponential control voltage response,
>so a linear pot will sweep them over a very wide range of frequency
>or gain.
>
>Neil Johnson (on this list) produced a 3 pole state variable using
>the SSM2164.
>
>1496s were used in several early VCFs - Wireless World and
>some Electronotes - but were largely abandoned when the 
>3080 and LM13600/13700 came along.
>
>> I know THAT corp seems to be targeting their VCA as a pro audio 
>> thang, is there really any difference between THAT VCA and the 
>> usual multipliers? aside from the CV is DC as oppose to AC?
>
>?  The CV is DC in both cases.  But they are expontial on the 
>THAT ones and linear on OTAs and multipliers and multipliers
>can handle bipolar CVs.  
>
>The THAT Corp VCAs are vastly superior to OTAs and
>multipliers in audio applications - much wider range, lower
>noise, lower distortion.
>
>> Find it very intersting on Ebay people paid some pretty good money for CA3080,
>> while there are all these ICs available some are as cheap as 50c but some cost
>> $50USD!!!!!!!
>> 
>> Thoughts? 
>
>If there are that many idiots out there, maybe I should buy some
>3080s and put them on ebay.  Mayne the ones in TO99 cans
>are harder to find.
>
>
>Steve
>
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