Doepfer

As anyone who owns a spring reverb module knows, the A-100's 
transformer generates a lot of hum. In addition to the spring 
reverb, I use a lot of electromagnetic pick-ups (like on a guitar) 
as external signal inputs  and find the hum almost unacceptable 
with this set-up. I hope someone might have suggestions for 
shielding the transformer, or knows of other ways to decrease 
the hum generated by the A-100.

My A-126 Frequency Shifter seems to add a sine wave of almost 
equal strength to any signal I plug into the module, has anyone 
else had this problem? I don't seem to be able to frequency shift 
anything without adding a loud sine tone to it, even when using 
high input signal coming from an A-110, for example.

I'd also like to know about ways to create a manual gate, without 
a keyboard. A simple way to open/close a signal path...

To the person who asked about the spring reverb, I like it a lot. It 
adds a very characteristic sound of its own, because of the 
resonance of the springs, so it's in no way a "neutral" sounding 
reverb. The springs offer very tactile ways for changing sounds 
though, because they're very sensitive to vibration. 


Thanks,

Dimm M.

thanks mdimmm,
i asked for the a199...as for your other questions...i
don't have the freq. shifter so i can't help you on
that...a way to create a manual gate is by using the
a155 stopped(but with the start button on,i think...)
in a step you want and send gate signals from the gate
output(row 4),also with the cv source module if you
turn the knob fully to the right it send a+5volts
signal so you can use it like a gate source....

bakis.

--- mdimmm <mdimmm@yahoo.com> wrote:
> As anyone who owns a spring reverb module knows, the
> A-100's 
> transformer generates a lot of hum. In addition to
> the spring 
> reverb, I use a lot of electromagnetic pick-ups
> (like on a guitar) 
> as external signal inputs  and find the hum almost
> unacceptable 
> with this set-up. I hope someone might have
> suggestions for 
> shielding the transformer, or knows of other ways to
> decrease 
> the hum generated by the A-100.
> 
> My A-126 Frequency Shifter seems to add a sine wave
> of almost 
> equal strength to any signal I plug into the module,
> has anyone 
> else had this problem? I don't seem to be able to
> frequency shift 
> anything without adding a loud sine tone to it, even
> when using 
> high input signal coming from an A-110, for example.
> 
> I'd also like to know about ways to create a manual
> gate, without 
> a keyboard. A simple way to open/close a signal
> path...
> 
> To the person who asked about the spring reverb, I
> like it a lot. It 
> adds a very characteristic sound of its own, because
> of the 
> resonance of the springs, so it's in no way a
> "neutral" sounding 
> reverb. The springs offer very tactile ways for
> changing sounds 
> though, because they're very sensitive to vibration.
> 
> 
> 
> Thanks,
> 
> Dimm M.
> 
> 


=====
synthfreak(parallel worlds)
athens-greece
[Doepfer_a100] group owner-moderator

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--- In Doepfer_a100@y..., "mdimmm" <mdimmm@y...> wrote:
> As anyone who owns a spring reverb module knows, the 
A-100's 
> transformer generates a lot of hum. In addition to the spring 
> reverb, I use a lot of electromagnetic pick-ups (like on a guitar) 
> as external signal inputs  and find the hum almost 
unacceptable 
> with this set-up. I hope someone might have suggestions for 
> shielding the transformer, or knows of other ways to decrease 
> the hum generated by the A-100.


dimm, 
re:  reverb hum, i drilled a small hole in the back of the case and 
soldered a longer rca cable to the module so the springs live 
outside the A100 case completely.  not a trace of hum.  (you 
could just get an extention to the cable that's already there but 
that requires drilling a bigger hole for the connector to pass 
through.)  one benefit for me is this also allows manipulation of 
the spings if so desired, which can be very interesting, 
particularly  when the reverb is patched thru the resonance 
feedback loop on a filter.
duff

ps  message 1000?  wow!  cheers to bakis for starting this list!

> --- In Doepfer_a100@y..., "mdimmm" <mdimmm@y...> wrote:
> > As anyone who owns a spring reverb module knows, the 
> A-100's 
> > transformer generates a lot of hum. In addition to the spring 
> > reverb, I use a lot of electromagnetic pick-ups (like on a 
guitar) 
> > as external signal inputs  and find the hum almost 
> unacceptable 
> > with this set-up. I hope someone might have suggestions for 
> > shielding the transformer, or knows of other ways to 
decrease 
> > the hum generated by the A-100.


ok, re-read your question.  sorry to answer re reverb hum when 
you're speaking primarily of transformer hum in general.  no idea 
how to shield it (good question). and i'm no ecectrician but i find 
putting an ebtech inline transformer in the signal path to or from 
the A100 to work 98% of the time.  these are handy regardless.  
for live shows i run my A100 into stereo guitar amps alot (plus DI 
boxes) and nearly always have hum in one amp w/o the ebtech 
box (model#HE2PKG), especially in europe where it's necessary 
to use a power transformer to step down to 120vAC.  also in the 
studio i'm often dealing w impedence nightmares and the little 
box usually kills the hum somehow.
duff

> I'd also like to know about ways to create a manual gate, without 
> a keyboard. A simple way to open/close a signal path...

Try this:
A-176 (CV 3) ==>  A-150 (CV)
Turn the A-176 (CV 3). The A-150  <=> generates a gate.

Josef

Sorry, I forgot a connection...

> I'd also like to know about ways to create a manual gate, without 
> a keyboard. A simple way to open/close a signal path... 

Try this: 
A-176 (CV 3) ==> A-150 (CV) 
A-176 (CV 1)  <=>  A-150 (O/I)
Set A-176 (CV 1 = 10, Fine = 10)
Turn the A-176 (CV 3). The A-150 (I/O 1) or  (I/O 2) generates a gate. 

Josef

> I'd also like to know about ways to create a manual gate, without 
> a keyboard. A simple way to open/close a signal path...

I find a simple way to produce a manual gate (for use with the ADSRs
140 and 141 at least) is to use an A-174 joystick. Set the X out to be
just negative, then tapping the joystick to the right sends it
sufficently positive to gate the ADSR.

> To the person who asked about the spring reverb, I like it a lot. It 
> adds a very characteristic sound of its own, because of the 

The spring reverb is one of my favourite modules - much screeching and
squawking to be had by using the feedback. I'm even considering buying
a second one to see what might happen if I cross couple them! (The hum
problem *is* a real pain in the proverbial though...)
 
> My A-126 Frequency Shifter seems to add a sine wave of almost 
> equal strength to any signal I plug into the module, has anyone 
> else had this problem? I don't seem to be able to frequency shift 

I'm wondering whether you had the same problem as I did when I first
got mine - for example, if the frequency you feed in is quite low, and
then you try and shift it down, the output shifts lower and then
passes through zero frequency to give 'negative frequency', which
actually sounds like a normal positive frequency, but as you continue
to increase the down shift, you actually hear this frequency
increasing, which sounds like the module is not working! If this is
what you are getting, input a much higher frequency, and then shift
down, and you should actually hear the output frequency decreasing.

Tim

[The views expressed above are entirely those of the writer and do not
represent the views, policy or understanding of any other person or
official body.]

--- In Doepfer_a100@y..., "stinchcombe_t" <tstinchcombe@q...> 
wrote:
> > I'd also like to know about ways to create a manual gate, 
without 
> > a keyboard. A simple way to open/close a signal path...
> 
> I find a simple way to produce a manual gate (for use with the 
ADSRs
> 140 and 141 at least) is to use an A-174 joystick. Set the X out 
to be
> just negative, then tapping the joystick to the right sends it
> sufficently positive to gate the ADSR.
> 

There's no module with an actual "manual gate" button though, 
is there? Like on a VCS3...

An A-119 works well too. Touch the other end of a cable which 
goes into the input, turn up gain all the way, threshold all the way 
down.

> > To the person who asked about the spring reverb, I like it a 
lot. It 
> > adds a very characteristic sound of its own, because of the 
> 
> The spring reverb is one of my favourite modules - much 
screeching and
> squawking to be had by using the feedback. I'm even 
considering buying
> a second one to see what might happen if I cross couple them! 
(The hum
> problem *is* a real pain in the proverbial though...)
>  
> > My A-126 Frequency Shifter seems to add a sine wave of 
almost 
> > equal strength to any signal I plug into the module, has 
anyone 
> > else had this problem? I don't seem to be able to frequency 
shift 
> 
> I'm wondering whether you had the same problem as I did 
when I first
> got mine - for example, if the frequency you feed in is quite low, 
and
> then you try and shift it down, the output shifts lower and then
> passes through zero frequency to give 'negative frequency', 
which
> actually sounds like a normal positive frequency, but as you 
continue
> to increase the down shift, you actually hear this frequency
> increasing, which sounds like the module is not working! If this 
is
> what you are getting, input a much higher frequency, and then 
shift
> down, and you should actually hear the output frequency 
decreasing.

I'm not sure I know what you mean. I meant that the A-126 
seems to self-oscillate, all the time, and add this signal to the 
output, more than I'd like it to.

Dimm M.
> 
> Tim
> 
> [The views expressed above are entirely those of the writer and 
do not
> represent the views, policy or understanding of any other 
person or
> official body.]

The light sensor module and the Theremin module both have gate outputs with
threshold settings which can work like a trigger button.


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

From: "mdimmm" <mdimmm@yahoo.com>
To: <Doepfer_a100@yahoogroups.com>
Sent: Wednesday, March 06, 2002 8:42 AM
Subject: [Doepfer_a100] Re: Various questions


> --- In Doepfer_a100@y..., "stinchcombe_t" <tstinchcombe@q...>
> wrote:
> > > I'd also like to know about ways to create a manual gate,
> without
> > > a keyboard. A simple way to open/close a signal path...
> >
> > I find a simple way to produce a manual gate (for use with the
> ADSRs
> > 140 and 141 at least) is to use an A-174 joystick. Set the X out
> to be
> > just negative, then tapping the joystick to the right sends it
> > sufficently positive to gate the ADSR.
> >
>
> There's no module with an actual "manual gate" button though,
> is there? Like on a VCS3...
>
> An A-119 works well too. Touch the other end of a cable which
> goes into the input, turn up gain all the way, threshold all the way
> down.
>
> > > To the person who asked about the spring reverb, I like it a
> lot. It
> > > adds a very characteristic sound of its own, because of the
> >
> > The spring reverb is one of my favourite modules - much
> screeching and
> > squawking to be had by using the feedback. I'm even
> considering buying
> > a second one to see what might happen if I cross couple them!
> (The hum
> > problem *is* a real pain in the proverbial though...)
> >
> > > My A-126 Frequency Shifter seems to add a sine wave of
> almost
> > > equal strength to any signal I plug into the module, has
> anyone
> > > else had this problem? I don't seem to be able to frequency
> shift
> >
> > I'm wondering whether you had the same problem as I did
> when I first
> > got mine - for example, if the frequency you feed in is quite low,
> and
> > then you try and shift it down, the output shifts lower and then
> > passes through zero frequency to give 'negative frequency',
> which
> > actually sounds like a normal positive frequency, but as you
> continue
> > to increase the down shift, you actually hear this frequency
> > increasing, which sounds like the module is not working! If this
> is
> > what you are getting, input a much higher frequency, and then
> shift
> > down, and you should actually hear the output frequency
> decreasing.
>
> I'm not sure I know what you mean. I meant that the A-126
> seems to self-oscillate, all the time, and add this signal to the
> output, more than I'd like it to.
>
> Dimm M.
> >
> > Tim
> >
> > [The views expressed above are entirely those of the writer and
> do not
> > represent the views, policy or understanding of any other
> person or
> > official body.]
>
>
>
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