Doepfer

I'm really confused on this one.

I have an a121 multimode filter that doesn't filter external sources.
At first I thought the filter was not functioning at all. The
resonance will self oscillate and allow hints of what was coming in
from the external source.  Then, I patched it in a conventional synth
path.

This works:

When I patch it in vco -> a121 -> vca, it modifies the sound as
intended (hp/lp/bp/notch).

These don't:

When I patch in external source (drum machine/iphone) -> a121, I
barely get anything.  The same if I patch ext source -> vca -> a121 or
ext source -> vca -> a121 -> vca.
When I have more complex sources like vco -> vca -> bbd (188-2) ->
a121, the result is the same as the external source.

Conclusion:

It only seems to filter when I send in simple wave forms from a vco.

Notes:

My other filters (a120/a106-5), allow me to patch in external sources
(iphone/drummachine) and work as expected.

Is there something unique about the a121 and complex wave forms that
I'm missing?  Is my a121 toast?

are you using an external input module of some kind to bring the  
external input up to 'modular" levels?
if not, i'd say that's your problem.

On 15 Aug 2009, at 17:32, Greg Cerveny wrote:

> I'm really confused on this one.
>
> I have an a121 multimode filter that doesn't filter external sources.
> At first I thought the filter was not functioning at all. The
> resonance will self oscillate and allow hints of what was coming in
> from the external source. Then, I patched it in a conventional synth
> path.
>
> This works:
>
> When I patch it in vco -> a121 -> vca, it modifies the sound as
> intended (hp/lp/bp/notch).
>
> These don't:
>
> When I patch in external source (drum machine/iphone) -> a121, I
> barely get anything. The same if I patch ext source -> vca -> a121 or
> ext source -> vca -> a121 -> vca.
> When I have more complex sources like vco -> vca -> bbd (188-2) ->
> a121, the result is the same as the external source.
>
> Conclusion:
>
> It only seems to filter when I send in simple wave forms from a vco.
>
> Notes:
>
> My other filters (a120/a106-5), allow me to patch in external sources
> (iphone/drummachine) and work as expected.
>
> Is there something unique about the a121 and complex wave forms that
> I'm missing? Is my a121 toast?
> 



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

Hey Sandy,

I tried putting it through an a-131 to bring the level up, do you
think that would be enough?

Curiously, why would an a-120 and an a-106-5 would filter the source
untreated, but the a-121 need it amplified?

Thanks!  I'm still new to this and trying to figure it all out.

-Greg

On Sat, Aug 15, 2009 at 11:01 AM, Sandy Brain<sandybrain@gmail.com> wrote:
>
>
> are you using an external input module of some kind to bring the
> external input up to 'modular" levels?
> if not, i'd say that's your problem.
>
> On 15 Aug 2009, at 17:32, Greg Cerveny wrote:
>
>> I'm really confused on this one.
>>
>> I have an a121 multimode filter that doesn't filter external sources.
>> At first I thought the filter was not functioning at all. The
>> resonance will self oscillate and allow hints of what was coming in
>> from the external source. Then, I patched it in a conventional synth
>> path.
>>
>> This works:
>>
>> When I patch it in vco -> a121 -> vca, it modifies the sound as
>> intended (hp/lp/bp/notch).
>>
>> These don't:
>>
>> When I patch in external source (drum machine/iphone) -> a121, I
>> barely get anything. The same if I patch ext source -> vca -> a121 or
>> ext source -> vca -> a121 -> vca.
>> When I have more complex sources like vco -> vca -> bbd (188-2) ->
>> a121, the result is the same as the external source.
>>
>> Conclusion:
>>
>> It only seems to filter when I send in simple wave forms from a vco.
>>
>> Notes:
>>
>> My other filters (a120/a106-5), allow me to patch in external sources
>> (iphone/drummachine) and work as expected.
>>
>> Is there something unique about the a121 and complex wave forms that
>> I'm missing? Is my a121 toast?
>>
>
> [Non-text portions of this message have been removed]
>
>

Most modular VCAs, such as A131, are actually only attenuators.  The
amplitude of an ipod signal is much less than a VCO and would thus need to
be stepped up to be in the same range as a VCO.  The forthcoming A183
amplifies signals, and the already available A133 also amplifies.  You can
get one of these but an immediate solution would just be to adjust levels on
your main amp/PA.  For example I use a PA designed for keyboards that has
multiple inputs with independent level controls, and if I want to play my
analog synth at the same time as an mp3, then I'd just put the synth line
level really low compared to the mp3 line.
Monroe

On Sat, Aug 15, 2009 at 10:34 AM, Greg Cerveny <greg.cerveny@gmail.com>wrote:

>
>
> Hey Sandy,
>
> I tried putting it through an a-131 to bring the level up, do you
> think that would be enough?
>
> Curiously, why would an a-120 and an a-106-5 would filter the source
> untreated, but the a-121 need it amplified?
>
> Thanks! I'm still new to this and trying to figure it all out.
>
> -Greg
>
>
> On Sat, Aug 15, 2009 at 11:01 AM, Sandy Brain<sandybrain@gmail.com<sandybrain%40gmail.com>>
> wrote:
> >
> >
> > are you using an external input module of some kind to bring the
> > external input up to 'modular" levels?
> > if not, i'd say that's your problem.
> >
> > On 15 Aug 2009, at 17:32, Greg Cerveny wrote:
> >
> >> I'm really confused on this one.
> >>
> >> I have an a121 multimode filter that doesn't filter external sources.
> >> At first I thought the filter was not functioning at all. The
> >> resonance will self oscillate and allow hints of what was coming in
> >> from the external source. Then, I patched it in a conventional synth
> >> path.
> >>
> >> This works:
> >>
> >> When I patch it in vco -> a121 -> vca, it modifies the sound as
> >> intended (hp/lp/bp/notch).
> >>
> >> These don't:
> >>
> >> When I patch in external source (drum machine/iphone) -> a121, I
> >> barely get anything. The same if I patch ext source -> vca -> a121 or
> >> ext source -> vca -> a121 -> vca.
> >> When I have more complex sources like vco -> vca -> bbd (188-2) ->
> >> a121, the result is the same as the external source.
> >>
> >> Conclusion:
> >>
> >> It only seems to filter when I send in simple wave forms from a vco.
> >>
> >> Notes:
> >>
> >> My other filters (a120/a106-5), allow me to patch in external sources
> >> (iphone/drummachine) and work as expected.
> >>
> >> Is there something unique about the a121 and complex wave forms that
> >> I'm missing? Is my a121 toast?
> >>
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
>  
>


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

you could also use the A119
http://www.doepfer.de/a119.htm

as Monroe says, the VCA won't amplify your external signal




On 15 Aug 2009, at 18:34, Greg Cerveny wrote:

> Hey Sandy,
>
> I tried putting it through an a-131 to bring the level up, do you
> think that would be enough?
>
> Curiously, why would an a-120 and an a-106-5 would filter the source
> untreated, but the a-121 need it amplified?
>
> Thanks! I'm still new to this and trying to figure it all out.
>
> -Greg
>
> On Sat, Aug 15, 2009 at 11:01 AM, Sandy Brain<sandybrain@gmail.com>  
> wrote:
> >
> >
> > are you using an external input module of some kind to bring the
> > external input up to 'modular" levels?
> > if not, i'd say that's your problem.
> >
> > On 15 Aug 2009, at 17:32, Greg Cerveny wrote:
> >
> >> I'm really confused on this one.
> >>
> >> I have an a121 multimode filter that doesn't filter external  
> sources.
> >> At first I thought the filter was not functioning at all. The
> >> resonance will self oscillate and allow hints of what was coming in
> >> from the external source. Then, I patched it in a conventional  
> synth
> >> path.
> >>
> >> This works:
> >>
> >> When I patch it in vco -> a121 -> vca, it modifies the sound as
> >> intended (hp/lp/bp/notch).
> >>
> >> These don't:
> >>
> >> When I patch in external source (drum machine/iphone) -> a121, I
> >> barely get anything. The same if I patch ext source -> vca ->  
> a121 or
> >> ext source -> vca -> a121 -> vca.
> >> When I have more complex sources like vco -> vca -> bbd (188-2) ->
> >> a121, the result is the same as the external source.
> >>
> >> Conclusion:
> >>
> >> It only seems to filter when I send in simple wave forms from a  
> vco.
> >>
> >> Notes:
> >>
> >> My other filters (a120/a106-5), allow me to patch in external  
> sources
> >> (iphone/drummachine) and work as expected.
> >>
> >> Is there something unique about the a121 and complex wave forms  
> that
> >> I'm missing? Is my a121 toast?
> >>
> >
> > [Non-text portions of this message have been removed]
> >
> >
> 



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

The A119 is actually especially made for external signal input amplification.
Next to that you can also derive an envelope following CV and you can
derive gate signals from incoming audio with this module.
I use it all the time. By this time I own 4 of them to get external fx
and samples into the system.

On Sat, Aug 15, 2009 at 8:29 PM, Sandy Brain<sandybrain@gmail.com> wrote:
>
>
> you could also use the A119
> http://www.doepfer.de/a119.htm
>
> as Monroe says, the VCA won't amplify your external signal
>
> On 15 Aug 2009, at 18:34, Greg Cerveny wrote:
>
>> Hey Sandy,
>>
>> I tried putting it through an a-131 to bring the level up, do you
>> think that would be enough?
>>
>> Curiously, why would an a-120 and an a-106-5 would filter the source
>> untreated, but the a-121 need it amplified?
>>
>> Thanks! I'm still new to this and trying to figure it all out.
>>
>> -Greg
>>
>> On Sat, Aug 15, 2009 at 11:01 AM, Sandy Brain<sandybrain@gmail.com>
>> wrote:
>> >
>> >
>> > are you using an external input module of some kind to bring the
>> > external input up to 'modular" levels?
>> > if not, i'd say that's your problem.
>> >
>> > On 15 Aug 2009, at 17:32, Greg Cerveny wrote:
>> >
>> >> I'm really confused on this one.
>> >>
>> >> I have an a121 multimode filter that doesn't filter external
>> sources.
>> >> At first I thought the filter was not functioning at all. The
>> >> resonance will self oscillate and allow hints of what was coming in
>> >> from the external source. Then, I patched it in a conventional
>> synth
>> >> path.
>> >>
>> >> This works:
>> >>
>> >> When I patch it in vco -> a121 -> vca, it modifies the sound as
>> >> intended (hp/lp/bp/notch).
>> >>
>> >> These don't:
>> >>
>> >> When I patch in external source (drum machine/iphone) -> a121, I
>> >> barely get anything. The same if I patch ext source -> vca ->
>> a121 or
>> >> ext source -> vca -> a121 -> vca.
>> >> When I have more complex sources like vco -> vca -> bbd (188-2) ->
>> >> a121, the result is the same as the external source.
>> >>
>> >> Conclusion:
>> >>
>> >> It only seems to filter when I send in simple wave forms from a
>> vco.
>> >>
>> >> Notes:
>> >>
>> >> My other filters (a120/a106-5), allow me to patch in external
>> sources
>> >> (iphone/drummachine) and work as expected.
>> >>
>> >> Is there something unique about the a121 and complex wave forms
>> that
>> >> I'm missing? Is my a121 toast?
>> >>
>> >
>> > [Non-text portions of this message have been removed]
>> >
>> >
>>
>
> [Non-text portions of this message have been removed]
>
>

Thanks all.  I guess I was misunderstanding the VCAs!

I still think it's weird that the a120/a106-5 filter it without amplification.

An a119 and the a133 are both on my wishlist.  The a133 especially for
use with my BBDs.

I have an mf-101 en route and am looking forward to the envelope
following fun.

On Sat, Aug 15, 2009 at 1:36 PM,
achtung_999<heinrich.himmelwasser@gmail.com> wrote:

>
>
> The A119 is actually especially made for external signal input
> amplification.
> Next to that you can also derive an envelope following CV and you can
> derive gate signals from incoming audio with this module.
> I use it all the time. By this time I own 4 of them to get external fx
> and samples into the system.
>
> On Sat, Aug 15, 2009 at 8:29 PM, Sandy Brain<sandybrain@gmail.com> wrote:
>>
>>
>> you could also use the A119
>> http://www.doepfer.de/a119.htm
>>
>> as Monroe says, the VCA won't amplify your external signal
>>
>> On 15 Aug 2009, at 18:34, Greg Cerveny wrote:
>>
>>> Hey Sandy,
>>>
>>> I tried putting it through an a-131 to bring the level up, do you
>>> think that would be enough?
>>>
>>> Curiously, why would an a-120 and an a-106-5 would filter the source
>>> untreated, but the a-121 need it amplified?
>>>
>>> Thanks! I'm still new to this and trying to figure it all out.
>>>
>>> -Greg
>>>
>>> On Sat, Aug 15, 2009 at 11:01 AM, Sandy Brain<sandybrain@gmail.com>
>>> wrote:
>>> >
>>> >
>>> > are you using an external input module of some kind to bring the
>>> > external input up to 'modular" levels?
>>> > if not, i'd say that's your problem.
>>> >
>>> > On 15 Aug 2009, at 17:32, Greg Cerveny wrote:
>>> >
>>> >> I'm really confused on this one.
>>> >>
>>> >> I have an a121 multimode filter that doesn't filter external
>>> sources.
>>> >> At first I thought the filter was not functioning at all. The
>>> >> resonance will self oscillate and allow hints of what was coming in
>>> >> from the external source. Then, I patched it in a conventional
>>> synth
>>> >> path.
>>> >>
>>> >> This works:
>>> >>
>>> >> When I patch it in vco -> a121 -> vca, it modifies the sound as
>>> >> intended (hp/lp/bp/notch).
>>> >>
>>> >> These don't:
>>> >>
>>> >> When I patch in external source (drum machine/iphone) -> a121, I
>>> >> barely get anything. The same if I patch ext source -> vca ->
>>> a121 or
>>> >> ext source -> vca -> a121 -> vca.
>>> >> When I have more complex sources like vco -> vca -> bbd (188-2) ->
>>> >> a121, the result is the same as the external source.
>>> >>
>>> >> Conclusion:
>>> >>
>>> >> It only seems to filter when I send in simple wave forms from a
>>> vco.
>>> >>
>>> >> Notes:
>>> >>
>>> >> My other filters (a120/a106-5), allow me to patch in external
>>> sources
>>> >> (iphone/drummachine) and work as expected.
>>> >>
>>> >> Is there something unique about the a121 and complex wave forms
>>> that
>>> >> I'm missing? Is my a121 toast?
>>> >>
>>> >
>>> > [Non-text portions of this message have been removed]
>>> >
>>> >
>>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>
>