Doepfer

In trying to pursue this Buchla-style experiment, I've found it almost
impossible to derive a decent audio-trigger from an ADSR envelope, no
matter how fast. Gates work nicely, but you're forced to have two
events: one on key-press and one on release.

I've got plenty of ADSRs, VCAs, Comparators and other things, and have
tried using the voltage comparator to create a gate from an ADSR
(close but no cigar). Can anyone suggest a way of generating a trigger?

Do you have an A-162? 

It would be nice to have a quad gate->trigger generator in a 4HP panel
though. 


--- In Doepfer_a100@yahoogroups.com, "madrayken" <dene.carter@...> wrote:

>
> In trying to pursue this Buchla-style experiment, I've found it almost
> impossible to derive a decent audio-trigger from an ADSR envelope, no
> matter how fast. Gates work nicely, but you're forced to have two
> events: one on key-press and one on release.
> 
> I've got plenty of ADSRs, VCAs, Comparators and other things, and have
> tried using the voltage comparator to create a gate from an ADSR
> (close but no cigar). Can anyone suggest a way of generating a trigger?
>

Nope - no A-162. I have the voltage comparator, CV controlled LFO,
Quad ADSR, and Dual Polariser.

--- In Doepfer_a100@yahoogroups.com, "Doug" <dougc356@...> wrote:
>
> Do you have an A-162? 
> 
> It would be nice to have a quad gate->trigger generator in a 4HP panel
> though. 
> 
> 
> --- In Doepfer_a100@yahoogroups.com, "madrayken" <dene.carter@> wrote:
> >
> > In trying to pursue this Buchla-style experiment, I've found it almost
> > impossible to derive a decent audio-trigger from an ADSR envelope, no
> > matter how fast. Gates work nicely, but you're forced to have two
> > events: one on key-press and one on release.
> > 
> > I've got plenty of ADSRs, VCAs, Comparators and other things, and have
> > tried using the voltage comparator to create a gate from an ADSR
> > (close but no cigar). Can anyone suggest a way of generating a
trigger?
> >
>

Hi madrayken

> In trying to pursue this Buchla-style experiment, I've found it almost
> impossible to derive a decent audio-trigger from an ADSR envelope, no
> matter how fast. 
I am not sure what you are asking for. What do you mean with 
"audio-trigger"?? A trigger signal generated as soon as the level of 
some audio signal is higher than a certain threshold (thats what I would 
understand)? Or do you mean an spike like the "klick"-sound from a drumpad?


> Gates work nicely, but you're forced to have two
> events: one on key-press and one on release.
This sentence i don't understand.

> I've got plenty of ADSRs, VCAs, Comparators and other things, and have
> tried using the voltage comparator to create a gate from an ADSR
> (close but no cigar). Can anyone suggest a way of generating a trigger?
I think you have a wrong understanding of the word "trigger".
- A trigger defines a point on the time axis and is usually technically 
achieved by a transition between two defined voltages. It defines the 
moment when a event starts to happen.
- A gate defines the duration of an event and starting point of this 
event. You may describe a gate as two triggers: one positive transition 
at the start of the gate and one negative transition at the end of the gate.

Taking this definition is respect, I am asking: for what patch exactly 
do you need two triggers? Knowing your answer to this question I might 
give you a more profound help.

Florian

Apologies - I think there's been a misunderstanding.

I'm trying to achieve the 'wooden block' sound as popularised by
Buchla synths.

I am using a resonant band-pass filter, and want to send a very short
'trigger' event to the filter's audio in. I have so far tried:

1) sending a short ADSR to the filter. The ADSR is not fast enough,
resulting in a 'tonnngg' rather than a 'tok' sound.
2) sending a signal straight from the midi-cv gate to the filter. The
problem here is that a signal is generated both on a press and release
of a key. As far as I am aware, this is because a gate represents a
shift from positive to negative, OR the reverse. 

What I want is a 'trigger' -  a very short square wave which occurs
only on key press.

Is that clearer? I do *not* need two triggers!



--- In Doepfer_a100@yahoogroups.com, Florian Anwander <fanwander@...>
wrote:
>
> Hi madrayken
> 
> > In trying to pursue this Buchla-style experiment, I've found it almost
> > impossible to derive a decent audio-trigger from an ADSR envelope, no
> > matter how fast. 
> I am not sure what you are asking for. What do you mean with 
> "audio-trigger"?? A trigger signal generated as soon as the level of 
> some audio signal is higher than a certain threshold (thats what I
would 
> understand)? Or do you mean an spike like the "klick"-sound from a
drumpad?
> 
> 
> > Gates work nicely, but you're forced to have two
> > events: one on key-press and one on release.
> This sentence i don't understand.
> 
> > I've got plenty of ADSRs, VCAs, Comparators and other things, and have
> > tried using the voltage comparator to create a gate from an ADSR
> > (close but no cigar). Can anyone suggest a way of generating a
trigger?
> I think you have a wrong understanding of the word "trigger".
> - A trigger defines a point on the time axis and is usually technically 
> achieved by a transition between two defined voltages. It defines the 
> moment when a event starts to happen.
> - A gate defines the duration of an event and starting point of this 
> event. You may describe a gate as two triggers: one positive transition 
> at the start of the gate and one negative transition at the end of
the gate.

> 
> Taking this definition is respect, I am asking: for what patch exactly 
> do you need two triggers? Knowing your answer to this question I might 
> give you a more profound help.
> 
> Florian
>

Three options come to mind:

1) Get an analog keyboard!  It's time.
2) The analogue systems RS50 has a trigger generator.
3) Using stuff you already have option:  Use an LFO with extremely low  
range and PWM and sync.  For PWM maybe you'll need a comparator.  Turn  
the range to the bottom, the PWM to the smallest spike, and use sync  
to create a trigger.

Option 1 is clearly the best.

Monroe

On Jan 10, 2009, at 4:06 PM, madrayken wrote:

> Apologies - I think there's been a misunderstanding.
>
> I'm trying to achieve the 'wooden block' sound as popularised by
> Buchla synths.
>
> I am using a resonant band-pass filter, and want to send a very short
> 'trigger' event to the filter's audio in. I have so far tried:
>
> 1) sending a short ADSR to the filter. The ADSR is not fast enough,
> resulting in a 'tonnngg' rather than a 'tok' sound.
> 2) sending a signal straight from the midi-cv gate to the filter. The
> problem here is that a signal is generated both on a press and release
> of a key. As far as I am aware, this is because a gate represents a
> shift from positive to negative, OR the reverse.
>
> What I want is a 'trigger' - a very short square wave which occurs
> only on key press.
>
> Is that clearer? I do *not* need two triggers!
>
> --- In Doepfer_a100@yahoogroups.com, Florian Anwander <fanwander@...>
> wrote:
> >
> > Hi madrayken
> >
> > > In trying to pursue this Buchla-style experiment, I've found it  
> almost
> > > impossible to derive a decent audio-trigger from an ADSR  
> envelope, no
> > > matter how fast.
> > I am not sure what you are asking for. What do you mean with
> > "audio-trigger"?? A trigger signal generated as soon as the level of
> > some audio signal is higher than a certain threshold (thats what I
> would
> > understand)? Or do you mean an spike like the "klick"-sound from a
> drumpad?
> >
> >
> > > Gates work nicely, but you're forced to have two
> > > events: one on key-press and one on release.
> > This sentence i don't understand.
> >
> > > I've got plenty of ADSRs, VCAs, Comparators and other things,  
> and have
> > > tried using the voltage comparator to create a gate from an ADSR
> > > (close but no cigar). Can anyone suggest a way of generating a
> trigger?
> > I think you have a wrong understanding of the word "trigger".
> > - A trigger defines a point on the time axis and is usually  
> technically
> > achieved by a transition between two defined voltages. It defines  
> the
> > moment when a event starts to happen.
> > - A gate defines the duration of an event and starting point of this
> > event. You may describe a gate as two triggers: one positive  
> transition
> > at the start of the gate and one negative transition at the end of
> the gate.
> >
> > Taking this definition is respect, I am asking: for what patch  
> exactly
> > do you need two triggers? Knowing your answer to this question I  
> might
> > give you a more profound help.
> >
> > Florian
> >
>
>
> 



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

---  <monroe.eskew@...> wrote:
>
> Three options come to mind:
> 
> 1) Get an analog keyboard!  It's time.

hmmm, only a small number of analog keyboards have a trig output since many 
manufacturers who needed a trigger just derive one from the incoming gate. 

That said one of the complaints about the current Buchla 200e regarding cv interfacing 
with other brands is Buchla's use of a very short duration 10v trigger dropping to a 5v gate 
because other analog gear has trouble generating it. But then again I don't think Buchla 
users are using that trig directly on the Low Pass Gate, mostly it controls the function 
generator (= ASR envelopes)

So your experimental goal is to generate a very short duration control voltage event, say 
+5v, right?

Though I'm thinking you might want to try a VCA after the resonating filter to come closer 
to a Buchla kind of sound that I guess you want since a Buchla is frequently using a 
lowpass filter and a vca-like processor in tandem, but since both are vactrol you have 
some lag in their response. 

I would have thought a minimum attack and decay sustain and release from an A-140 set 
to "L" ought to be sufficiently short. 

nick

Perhaps amping up an audio spike might be usable? But one needs to be a bit careful not 
to go too far with too hot signals

--- In Doepfer_a100@yahoogroups.com, "nicholas_kent" <zaum@...> wrote:
>
> ---  <monroe.eskew@> wrote:
> So your experimental goal is to generate a very short duration
control voltage event, say 
> +5v, right?

Correct. And only one per key press - not pairs, as you get with
midi->cv gates.

> Though I'm thinking you might want to try a VCA after the resonating
filter to come closer 
> to a Buchla kind of sound that I guess you want since a Buchla is
frequently using a 
> lowpass filter and a vca-like processor in tandem, but since both
are vactrol you have 
> some lag in their response. 

Hmm... that's so obvious I missed it. I could use my adsr to attenuate
the 'release' gate-derived sound from the filter.

> I would have thought a minimum attack and decay sustain and release
from an A-140 set 
> to "L" ought to be sufficiently short. 

Yes - I thought so too, initially, but the result definitely sounds
worse than sending the gate to the VCF.

> nick
> 
> Perhaps amping up an audio spike might be usable? But one needs to
be a bit careful not 
> to go too far with too hot signals

Not sure how I'd do that.

As an aside, would I still have the same challenges (i.e. need to
derive a trigger) if I was using a low-pass gate to create the
wooden-block sound?

Hi madrayken

> I am using a resonant band-pass filter, and want to send a very short
> 'trigger' event to the filter's audio in. I have so far tried:
> 
> 1) sending a short ADSR to the filter. The ADSR is not fast enough,
> resulting in a 'tonnngg' rather than a 'tok' sound.That is
Ok, this is not a fault of the trigger, but the rsonance of your 
bandpass is set to high.


> What I want is a 'trigger' -  a very short square wave which occurs
> only on key press.
The A162 trigger delay can produce something link this if bothe values 
are set to the shortest range. Or you use an short ADSR and send it to 
an comparator. This will result also in a short trigger.

But as I wrote: The extreme short ADSR causes assumingly the correct 
impuls as the trigger, but your filter setting is wrong. Don't change 
the trigger. Change the filter.

Florian

Analogue Systems keyboards have dedicated trigger out.

On Jan 10, 2009, at 11:44 PM, nicholas_kent wrote:

> hmmm, only a small number of analog keyboards have a trig output  
> since many
> manufacturers who needed a trigger just derive one from the incoming  
> gate.



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

On 1/11/09, madrayken <dene.carter@gmail.com> wrote:
> As an aside, would I still have the same challenges (i.e. need to
> derive a trigger) if I was using a low-pass gate to create the
> wooden-block sound?

If what you really want is to derive a trigger from gates, the
appropriate tool for the job is the doepfer dual gate delay. The
module takes in gates and spits out gates with variable delay and gate
length. If you set. Both delay and length to full minimum, it creates
a suitable trigger from the gate. I use it more for this than it's
intended purpose, actually.

-Brandon

--- In Doepfer_a100@yahoogroups.com, bdu@... wrote:
>
> On 1/11/09, madrayken <dene.carter@...> wrote:
> > As an aside, would I still have the same challenges (i.e. need to
> > derive a trigger) if I was using a low-pass gate to create the
> > wooden-block sound?
> 
> If what you really want is to derive a trigger from gates, the
> appropriate tool for the job is the doepfer dual gate delay. The
> module takes in gates and spits out gates with variable delay and gate
> length. If you set. Both delay and length to full minimum, it creates
> a suitable trigger from the gate. I use it more for this than it's
> intended purpose, actually.
> 
> -Brandon
>

That sounds perfect. Out of interest, I presume I'd still need to do
this even with a vactrol Low Pass Gate? (i.e. vactrols would still
need a 'trigger' to achieve the same effect)

On Sun, Jan 11, 2009 at 2:39 PM, madrayken <dene.carter@gmail.com> wrote:
> That sounds perfect. Out of interest, I presume I'd still need to do
> this even with a vactrol Low Pass Gate? (i.e. vactrols would still
> need a 'trigger' to achieve the same effect)

I think you may be confusing two different ways to achieve a similar
(yet different in critical ways) percussion sound. I'll describe both,
and that should make clear the "trigger" usage for both.

1. spiked filter percussion: This is similar to what's used in many
old drum machines. You set a filter (usually bandpass) on the edge of
self-oscillation, then feed the audio input a trigger, this impulse
pushes the filter into oscillation temporarily until it decays
naturally back to silence. The end result is a transient click (from
the trigger) combined with a sinusoidal signal that decays out to
silence. If you tried to use a square gate in this case instead of the
trigger, you'd get new "spikes" into oscillation at each transition of
the waveform, with positive DC offset on every other percussive hit.
Triggers are better ;0)

2. Lowpass gate percussion: This is usually done with a pair of
oscillators in an FM configuration, the output of the carrier
oscillator going into either a single lowpass gate in "both" mode or
serial lowpass gates, first the lpf and then the vca. The trigger
signal is used here as the cv into the lpgs. This quick transient
allows the naturally-slow and interestingly-shaped characteristics of
the vactrol response to shine, and results in that classic lpg bonking
sound.

-Brandon

a DIY quicky:


Would the Doepfer buss board be capable of carrying +/-15V instead of  
+/-12V ?
I assume it does, but just want to make sure...


cheers,

_guy

Yes they will. The limitation will be in the current capacity which is 
fundamentally a feature of the copper track width and thickness.

Best Regards

(Mr) Laurie Biddulph
Phone: +61 (0)2 4340 0938
Mobile: 0400 257 645

Elby Designs
ABN: 70 022 727 605
http://www.elby-designs.com

This e-mail and any files transmitted with it are confidential and intended 
for the addressee only.
If you are not the addressee you may not copy, forward, disclose or 
otherwise use it, or any part of it, in any form whatsoever. If you have 
received this e-mail in error please notify the sender and ensure that all 
copies of this e-mail and any files transmitted with it are deleted.
Any views or opinions represented in this e-mail are solely those of the 
author and do not necessarily represent those of Elby Designs.
Although this e-mail and its attachments have been scanned for the presence 
of computer viruses, Elby Designs will not be liable for any losses as a 
result of any viruses being passed on.

Please consider the environment before printing this email

----- Original Message ----- 

From: "Guy Drieghe D." <guy@guyd2.com>
To: <Doepfer_a100@yahoogroups.com>
Sent: Monday, January 12, 2009 6:02 PM
Subject: [Doepfer_a100] buss board +/-15V


>a DIY quicky:
>
>
> Would the Doepfer buss board be capable of carrying +/-15V instead of
> +/-12V ?
> I assume it does, but just want to make sure...
>
>
> cheers,
>
> _guy
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

Thanks, Laurie.

I need to draw max. 800mA, so I guess I'll be fine.

I want to connect a "dirty" +15V to the Doepfer +5V buss as well, but  
that draws only 100mA. On second thought, maybe better not... that  
dirty +15V is feeding a high-frequency clock module, so perhaps that  
would result in crosstalk to the VCO's connected to the regulated  
+/-15V busses ?


_g

> Yes they will. The limitation will be in the current capacity which is
> fundamentally a feature of the copper track width and thickness.
>
> Best Regards
>
> (Mr) Laurie Biddulph
> Phone: +61 (0)2 4340 0938
> Mobile: 0400 257 645
>
> Elby Designs
> ABN: 70 022 727 605
> http://www.elby-designs.com
>


> ----- Original Message -----
>
> From: "Guy Drieghe D." <guy@guyd2.com>
> To: <Doepfer_a100@yahoogroups.com>
> Sent: Monday, January 12, 2009 6:02 PM
> Subject: [Doepfer_a100] buss board +/-15V
>
> >a DIY quicky:
> >
> >
> > Would the Doepfer buss board be capable of carrying +/-15V instead  
> of
> > +/-12V ?
> > I assume it does, but just want to make sure...
> >
> >
> > cheers,
> >
> > _guy

I would check with Dopefer to see if they can advise you of the current 
capacity of their bussboard but I would expect it to be in excess of 1A so 
your requirements shouldn't be a problem.

If the clock module has decent isolation on it's power rail then there 
should be little or no `leakage' back up the bussboard so in theory you 
shouldn't have a problem. Being on a separate rail is a good idea and would 
further reduce and potential problems.

If there is only the one device being connected to the dirty 15V then you 
might, in the long run, be better off connecting it directly at the power 
supply end of the bussboard or to the power supply itself. This gives a star 
connection which is far superior at minimising noise problems.

Best Regards

(Mr) Laurie Biddulph
Phone: +61 (0)2 4340 0938
Mobile: 0400 257 645

Elby Designs
ABN: 70 022 727 605
http://www.elby-designs.com

This e-mail and any files transmitted with it are confidential and intended 
for the addressee only.
If you are not the addressee you may not copy, forward, disclose or 
otherwise use it, or any part of it, in any form whatsoever. If you have 
received this e-mail in error please notify the sender and ensure that all 
copies of this e-mail and any files transmitted with it are deleted.
Any views or opinions represented in this e-mail are solely those of the 
author and do not necessarily represent those of Elby Designs.
Although this e-mail and its attachments have been scanned for the presence 
of computer viruses, Elby Designs will not be liable for any losses as a 
result of any viruses being passed on.

Please consider the environment before printing this email

----- Original Message ----- 

From: "Guy Drieghe D." <guy@guyd2.com>
To: <Doepfer_a100@yahoogroups.com>
Sent: Monday, January 12, 2009 6:35 PM
Subject: Re: [Doepfer_a100] buss board +/-15V


> Thanks, Laurie.
>
> I need to draw max. 800mA, so I guess I'll be fine.
>
> I want to connect a "dirty" +15V to the Doepfer +5V buss as well, but
> that draws only 100mA. On second thought, maybe better not... that
> dirty +15V is feeding a high-frequency clock module, so perhaps that
> would result in crosstalk to the VCO's connected to the regulated
> +/-15V busses ?
>
>
> _g
>
>
>> Yes they will. The limitation will be in the current capacity which is
>> fundamentally a feature of the copper track width and thickness.
>>
>> Best Regards
>>
>> (Mr) Laurie Biddulph
>> Phone: +61 (0)2 4340 0938
>> Mobile: 0400 257 645
>>
>> Elby Designs
>> ABN: 70 022 727 605
>> http://www.elby-designs.com
>>
>
>
>> ----- Original Message -----
>>
>> From: "Guy Drieghe D." <guy@guyd2.com>
>> To: <Doepfer_a100@yahoogroups.com>
>> Sent: Monday, January 12, 2009 6:02 PM
>> Subject: [Doepfer_a100] buss board +/-15V
>>
>> >a DIY quicky:
>> >
>> >
>> > Would the Doepfer buss board be capable of carrying +/-15V instead
>> of
>> > +/-12V ?
>> > I assume it does, but just want to make sure...
>> >
>> >
>> > cheers,
>> >
>> > _guy
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

Thanks again for the advice, Laurie !

Yes, now I remember vaguely (this system is 25 yo) that we had to  
redesign the original PSU and add that unregulated +15V just for the  
clock module, because of interference with the VCO's, which ran on the  
same regulated buss. We then connected the clock directly to the PSU -  
as per your suggestion - which took care of the interference.

I've redone the old PSU completely, with a slightly less "dirty" +15V,  
and was planning to use Doepfer's bussboard to connect the modules. I  
guess two loose wires for the dirty line ain't gonna kill my sense of  
neatness. ;-)

_guy [diy noob]

> I would check with Dopefer to see if they can advise you of the  
> current
> capacity of their bussboard but I would expect it to be in excess of  
> 1A so
> your requirements shouldn't be a problem.
>
> If the clock module has decent isolation on it's power rail then there
> should be little or no `leakage' back up the bussboard so in theory  
> you
> shouldn't have a problem. Being on a separate rail is a good idea  
> and would
> further reduce and potential problems.
>
> If there is only the one device being connected to the dirty 15V  
> then you
> might, in the long run, be better off connecting it directly at the  
> power
> supply end of the bussboard or to the power supply itself. This  
> gives a star
> connection which is far superior at minimising noise problems.
>
> Best Regards
>
> (Mr) Laurie Biddulph
> Phone: +61 (0)2 4340 0938
> Mobile: 0400 257 645
>
> Elby Designs
> ABN: 70 022 727 605
> http://www.elby-designs.com
>
> This e-mail and any files transmitted with it are confidential and  
> intended
> for the addressee only.
> If you are not the addressee you may not copy, forward, disclose or
> otherwise use it, or any part of it, in any form whatsoever. If you  
> have
> received this e-mail in error please notify the sender and ensure  
> that all
> copies of this e-mail and any files transmitted with it are deleted.
> Any views or opinions represented in this e-mail are solely those of  
> the
> author and do not necessarily represent those of Elby Designs.
> Although this e-mail and its attachments have been scanned for the  
> presence
> of computer viruses, Elby Designs will not be liable for any losses  
> as a
> result of any viruses being passed on.
>
> Please consider the environment before printing this email
>
> ----- Original Message -----
> From: "Guy Drieghe D." <guy@guyd2.com>
> To: <Doepfer_a100@yahoogroups.com>
> Sent: Monday, January 12, 2009 6:35 PM
> Subject: Re: [Doepfer_a100] buss board +/-15V
>
> > Thanks, Laurie.
> >
> > I need to draw max. 800mA, so I guess I'll be fine.
> >
> > I want to connect a "dirty" +15V to the Doepfer +5V buss as well,  
> but
> > that draws only 100mA. On second thought, maybe better not... that
> > dirty +15V is feeding a high-frequency clock module, so perhaps that
> > would result in crosstalk to the VCO's connected to the regulated
> > +/-15V busses ?
> >
> >
> > _g
> >
> >
> >> Yes they will. The limitation will be in the current capacity  
> which is
> >> fundamentally a feature of the copper track width and thickness.
> >>
> >> Best Regards
> >>
> >> (Mr) Laurie Biddulph
> >> Phone: +61 (0)2 4340 0938
> >> Mobile: 0400 257 645
> >>
> >> Elby Designs
> >> ABN: 70 022 727 605
> >> http://www.elby-designs.com
> >>
> >
> >
> >> ----- Original Message -----
> >>
> >> From: "Guy Drieghe D." <guy@guyd2.com>
> >> To: <Doepfer_a100@yahoogroups.com>
> >> Sent: Monday, January 12, 2009 6:02 PM
> >> Subject: [Doepfer_a100] buss board +/-15V
> >>
> >> >a DIY quicky:
> >> >
> >> >
> >> > Would the Doepfer buss board be capable of carrying +/-15V  
> instead
> >> of
> >> > +/-12V ?
> >> > I assume it does, but just want to make sure...
> >> >
> >> >
> >> > cheers,
> >> >
> >> > _guy
> >
> > -

Aha! Thanks for that, Brandon. That's much clearer now.

--- In Doepfer_a100@yahoogroups.com, "Brandon Daniel" <bdu@...> wrote:
>
> On Sun, Jan 11, 2009 at 2:39 PM, madrayken <dene.carter@...> wrote:
> > That sounds perfect. Out of interest, I presume I'd still need to 
do
> > this even with a vactrol Low Pass Gate? (i.e. vactrols would still
> > need a 'trigger' to achieve the same effect)
> 
> I think you may be confusing two different ways to achieve a similar
> (yet different in critical ways) percussion sound. I'll describe 
both,
> and that should make clear the "trigger" usage for both.
> 
> 1. spiked filter percussion: This is similar to what's used in many
> old drum machines. You set a filter (usually bandpass) on the edge 
of
> self-oscillation, then feed the audio input a trigger, this impulse
> pushes the filter into oscillation temporarily until it decays
> naturally back to silence. The end result is a transient click (from
> the trigger) combined with a sinusoidal signal that decays out to
> silence. If you tried to use a square gate in this case instead of 
the
> trigger, you'd get new "spikes" into oscillation at each transition 
of
> the waveform, with positive DC offset on every other percussive hit.
> Triggers are better ;0)
> 
> 2. Lowpass gate percussion: This is usually done with a pair of
> oscillators in an FM configuration, the output of the carrier
> oscillator going into either a single lowpass gate in "both" mode or
> serial lowpass gates, first the lpf and then the vca. The trigger
> signal is used here as the cv into the lpgs. This quick transient
> allows the naturally-slow and interestingly-shaped characteristics 
of
> the vactrol response to shine, and results in that classic lpg 
bonking

> sound.
> 
> -Brandon
>

I guess the point I hadn't thought of is that if a module does actually want 
to use the 5V rail for 5V then it will probably go bang so keeping it off 
the buss would be the right thing to do.....
You could use of the control lines with the same argument. being further 
away from the main power rails would offer the isolation you need.

I think the safe thing though is to stay away from the buss, not because of 
noise but because of the potential risk of damage to other modules.

Best Regards

(Mr) Laurie Biddulph
Phone: +61 (0)2 4340 0938
Mobile: 0400 257 645

Elby Designs
ABN: 70 022 727 605
http://www.elby-designs.com

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----- Original Message ----- 

From: "Guy Drieghe D." <guy@guyd2.com>
To: <Doepfer_a100@yahoogroups.com>
Sent: Monday, January 12, 2009 7:40 PM
Subject: Re: [Doepfer_a100] buss board +/-15V


> Thanks again for the advice, Laurie !
>
> Yes, now I remember vaguely (this system is 25 yo) that we had to
> redesign the original PSU and add that unregulated +15V just for the
> clock module, because of interference with the VCO's, which ran on the
> same regulated buss. We then connected the clock directly to the PSU -
> as per your suggestion - which took care of the interference.
>
> I've redone the old PSU completely, with a slightly less "dirty" +15V,
> and was planning to use Doepfer's bussboard to connect the modules. I
> guess two loose wires for the dirty line ain't gonna kill my sense of
> neatness. ;-)
>
> _guy [diy noob]
>
>
>
>> I would check with Dopefer to see if they can advise you of the
>> current
>> capacity of their bussboard but I would expect it to be in excess of
>> 1A so
>> your requirements shouldn't be a problem.
>>
>> If the clock module has decent isolation on it's power rail then there
>> should be little or no `leakage' back up the bussboard so in theory
>> you
>> shouldn't have a problem. Being on a separate rail is a good idea
>> and would
>> further reduce and potential problems.
>>
>> If there is only the one device being connected to the dirty 15V
>> then you
>> might, in the long run, be better off connecting it directly at the
>> power
>> supply end of the bussboard or to the power supply itself. This
>> gives a star
>> connection which is far superior at minimising noise problems.
>>
>> Best Regards
>>
>> (Mr) Laurie Biddulph
>> Phone: +61 (0)2 4340 0938
>> Mobile: 0400 257 645
>>
>> Elby Designs
>> ABN: 70 022 727 605
>> http://www.elby-designs.com
>>
>> This e-mail and any files transmitted with it are confidential and
>> intended
>> for the addressee only.
>> If you are not the addressee you may not copy, forward, disclose or
>> otherwise use it, or any part of it, in any form whatsoever. If you
>> have
>> received this e-mail in error please notify the sender and ensure
>> that all
>> copies of this e-mail and any files transmitted with it are deleted.
>> Any views or opinions represented in this e-mail are solely those of
>> the
>> author and do not necessarily represent those of Elby Designs.
>> Although this e-mail and its attachments have been scanned for the
>> presence
>> of computer viruses, Elby Designs will not be liable for any losses
>> as a
>> result of any viruses being passed on.
>>
>> Please consider the environment before printing this email
>>
>> ----- Original Message -----
>> From: "Guy Drieghe D." <guy@guyd2.com>
>> To: <Doepfer_a100@yahoogroups.com>
>> Sent: Monday, January 12, 2009 6:35 PM
>> Subject: Re: [Doepfer_a100] buss board +/-15V
>>
>> > Thanks, Laurie.
>> >
>> > I need to draw max. 800mA, so I guess I'll be fine.
>> >
>> > I want to connect a "dirty" +15V to the Doepfer +5V buss as well,
>> but
>> > that draws only 100mA. On second thought, maybe better not... that
>> > dirty +15V is feeding a high-frequency clock module, so perhaps that
>> > would result in crosstalk to the VCO's connected to the regulated
>> > +/-15V busses ?
>> >
>> >
>> > _g
>> >
>> >
>> >> Yes they will. The limitation will be in the current capacity
>> which is
>> >> fundamentally a feature of the copper track width and thickness.
>> >>
>> >> Best Regards
>> >>
>> >> (Mr) Laurie Biddulph
>> >> Phone: +61 (0)2 4340 0938
>> >> Mobile: 0400 257 645
>> >>
>> >> Elby Designs
>> >> ABN: 70 022 727 605
>> >> http://www.elby-designs.com
>> >>
>> >
>> >
>> >> ----- Original Message -----
>> >>
>> >> From: "Guy Drieghe D." <guy@guyd2.com>
>> >> To: <Doepfer_a100@yahoogroups.com>
>> >> Sent: Monday, January 12, 2009 6:02 PM
>> >> Subject: [Doepfer_a100] buss board +/-15V
>> >>
>> >> >a DIY quicky:
>> >> >
>> >> >
>> >> > Would the Doepfer buss board be capable of carrying +/-15V
>> instead
>> >> of
>> >> > +/-12V ?
>> >> > I assume it does, but just want to make sure...
>> >> >
>> >> >
>> >> > cheers,
>> >> >
>> >> > _guy
>> >
>> > -
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

Perhaps I'm still confused, but...

Would I still *need* a 162 to create trigger signals if I had a
vactrol low-pass gate?

--- In Doepfer_a100@yahoogroups.com, bdu@... wrote:

>
> On 1/11/09, madrayken <dene.carter@...> wrote:
> > As an aside, would I still have the same challenges (i.e. need to
> > derive a trigger) if I was using a low-pass gate to create the
> > wooden-block sound?
> 
> If what you really want is to derive a trigger from gates, the
> appropriate tool for the job is the doepfer dual gate delay. The
> module takes in gates and spits out gates with variable delay and gate
> length. If you set. Both delay and length to full minimum, it creates
> a suitable trigger from the gate. I use it more for this than it's
> intended purpose, actually.
> 
> -Brandon
>

If you want to send a trigger to the LPG and you have a gate, then 
yes you need the A-162 (or similar) to convert the gate to a 
trigger. Not sure what the LPG would have to do with it unless it is 
your desired destination:
Midi->Gate->A-162->Trigger->LPG




--- In Doepfer_a100@yahoogroups.com, "madrayken" <dene.carter@...> 
wrote:
>
> Perhaps I'm still confused, but...
> 
> Would I still *need* a 162 to create trigger signals if I had a
> vactrol low-pass gate?
> 
> --- In Doepfer_a100@yahoogroups.com, bdu@ wrote:
> >
> > On 1/11/09, madrayken <dene.carter@> wrote:
> > > As an aside, would I still have the same challenges (i.e. need 
to
> > > derive a trigger) if I was using a low-pass gate to create the
> > > wooden-block sound?
> > 
> > If what you really want is to derive a trigger from gates, the
> > appropriate tool for the job is the doepfer dual gate delay. The
> > module takes in gates and spits out gates with variable delay 
and gate
> > length. If you set. Both delay and length to full minimum, it 
creates
> > a suitable trigger from the gate. I use it more for this than 
it's

> > intended purpose, actually.
> > 
> > -Brandon
> >
>

Hi folks

Doepfer A111 VCO2 175 euroes
Plan B model 25 multitasking audio processor 155 Euroes

located in germany, will post anywhere and normally not so expensive. 
I'm also looking to trade for other Plan B stuff

Richard

forgot to add. Moogerfooger Murf 105 265 euroes, still under warranty.

thanks

Richard

Richard Scott wrote:

> Hi folks
> 
> Doepfer A111 VCO2 175 euroes
> Plan B model 25 multitasking audio processor 155 Euroes
> 
> located in germany, will post anywhere and normally not so expensive. 
> I'm also looking to trade for other Plan B stuff
> 
> Richard
>