hello ingo,
many thanks!
i also have another idea: if you add, to the bottom
a155 row output, a -3.2 volts offset(an a176 cv source
passed thru an a133 vc polarizer), you will then have
an AC output alternating between -3.2 and +3.2 volts,
of course, depending on the settings of the bottom
a155 row knobs (scale knob setting to 10).
so, in detail, for every bottom a155 row knob, the
setting "0" leads to -3.2volts, the setting "5" leads
to 0volts,the setting "10" leads to +3.2.
and this give us an AC output, if you set 4 knobs to
positive and four knobs to negative volts, in a
symmetrical way.
otherwise, you will have a wierd waveform with more
than 50% of the wave above and less than 50% of the
wave below zero(or vice versa).

bakis.






--- selfoscillate < synaptic_music@... > wrote:

>
>
> hello list,
>
> last weekend i made some tests with the a155,
> using it as a graphic vco. bakis told me, that
> i should post the results here, maybe they are
> of interest for anybody.
>
> as all of you may know, the a155 is dc-coupled
> and outputs only positive voltages. so if you use
> the a155 as a graphic vco, the audio waveform will
> be positive as well and not alternating around
> zero as usual. not a big deal, as there is no real
> audible difference between dc and ac, but if you
> use the waveform in the middle of a patch, the
> differences can be huge, for example when using
> the a155 output as a modulator for exponential fm
> with an a110 or a111 vco. so sometimes you may
> want to transform the dc voltage of the a155
> into an ac voltage in certain cases.
>
> here is a list of a100 modules which do this:
>
> all vcf's without exception
> a109 vca part
> a114 ringmod
> a119 external input
> a125 phaser
> a126 frequency shifter
> a128 fixed filter bank
> the old a130 and a131 vca's (with cem chips)
> a135 vc mixer
>
>
> now the modules where the a155 output remains dc:
>
> the new a131 vca (with ca3080 chips)
> a132 vca
> a133 polarizer
> a138a, a138b, a138c mixers
> a170, a171 slew limiters
>
>
> sorry if some modules are missing, but i couldn't
> test them all during the weekend.
>
> i hope this info is of use for anyone :-)
>
>
> best wishes
>
> ingo
>
>
>
>
>
>
>

=====
Bakis Siros
Parallel Worlds / Polariton
Athens-Greece
1 group owner
http://www.shimarecords.co.uk
http://www.ward12.com



__________________________________
Do you Yahoo!
Yahoo! Mail Address AutoComplete - You start. We finish.
http://promotions.yahoo.com/new_mail