[sdiy] Discrete blackmer vca

[Tom Wiltshire]

Is that an exponential or linear VCA Jim?

The THAT VCAs are all based on the blackmer gain cell, and they're exponential, but the Hearn Morley VCA is linear, so maybe George did something else? I'm not sure.

Thanks,
Tom


On 11 Feb 2012, at 07:29, James Patchell wrote:

> Anybody here experiment making Blackmer VCA's from discrete transistors?  I know it has been done.   I am pretty sure Hearn Morley does or will sell a discrete one in a module.  I thought it might be fun to experiment a bit with them.  Kind of the cool thing about them is that they take an input current and produce an output current with a gain that is controled by a voltage.
> 
> For those who may not know what a blackmer vca is, here is a link to a prelim schematic of a very basic (and descrete) BMvca
> 
> http://www.noniandjim.com/Jim/SMB2/SMB2.html
> 
> -Jim
> 
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