Doepfer

Hello,

Curious about the new version of A-132-3.  On the page for the A-132-4 it
says that at 0V it only attenuates -60db.  Is this true for the 132-3 as
well, or is there negative offset built into the pc board?

Thanks,
Monroe


[Non-text portions of this message have been removed]

hello monroe,

i think with all knobs fully ccw the a132/3
closes completely, so there is no signal coming through.
at least that is my impression when i'm using mine.

best wishes

ingo



--- In Doepfer_a100@yahoogroups.com, Monroe Eskew <monroe.eskew@...> wrote:

>
> Hello,
> 
> Curious about the new version of A-132-3.  On the page for the A-132-4 it
> says that at 0V it only attenuates -60db.  Is this true for the 132-3 as
> well, or is there negative offset built into the pc board?
> 
> Thanks,
> Monroe
> 
> 
> [Non-text portions of this message have been removed]
>

Are there any trimpots on the board of the SSM version?

Thanks,
Monroe

On Fri, Jan 7, 2011 at 4:01 AM, selfoscillate <synaptic_music@yahoo.com>wrote:

>
>
>
> hello monroe,
>
> i think with all knobs fully ccw the a132/3
> closes completely, so there is no signal coming through.
> at least that is my impression when i'm using mine.
>
> best wishes
>
> ingo
>
>
> --- In Doepfer_a100@yahoogroups.com <Doepfer_a100%40yahoogroups.com>,
> Monroe Eskew <monroe.eskew@...> wrote:
> >
> > Hello,
> >
> > Curious about the new version of A-132-3. On the page for the A-132-4 it
> > says that at 0V it only attenuates -60db. Is this true for the 132-3 as
> > well, or is there negative offset built into the pc board?
> >
> > Thanks,
> > Monroe
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>  
>


[Non-text portions of this message have been removed]

> Hello,
>
> Curious about the new version of A-132-3.  On the page for the A-132-4 it
> says that at 0V it only attenuates -60db.  Is this true for the 132-3 as
> well, or is there negative offset built into the pc board?
>
> Thanks,
> Monroe

It's different for the linear and exponential mode. In the linear mode the
max. attenuation is much less than -60dB. In the exponential mode one never
reaches -00 dB (infinite) in theory as in the exponential mode a certain
voltage difference corresponds to an attenuation in dB (e.g. -10dB/V or
20dB/V). In reality of course the signal disappears in the noise floor if
the attenuation exceeds a certain value. We tried and discussed several
control scales for the exponential mode of the new SSM2164 based VCAs. If
the control scale is flat (e.g. -10dB/V) one obtains a smooth attenuation
but the min. attentuation is limited unless a negative voltage is applied.
If the control scale is steeper (e.g. -20dB/V) a min. attenuation close to
zero is reached (e.g. -100dB for 5V range). But in this case the attenuation
comes very fast (-20dB or 1/10 at 80% of full scale, -40dB or 1/100 at
60%, -60dB or 1/1000 at 40%, -80dB or 1/10000 at 20%). So one has to find a
compromise between min. attenuation and control scale. The new exponential
VCAs (A-132-3 in exp. mode and A-132-4) have about -12V/dB which is a good
compromise from our point of view. But it would be possible to change the
scale by changing some resistors on board.

Best wishes
Dieter Doepfer
(Back from holiday)

> Are there any trimpots on the board of the SSM version?

No

Best wishes
Dieter Doepfer