MOTM

Ever since I built my MOTM I haven't liked the way the envelopes worked, yet 
I've never heard anybody else comment on them.  I'm wondering why not.  Is it 
just me that experiences the following problems?

1)  I patch up a sound and hit a key on the keyboard to trigger the sound and 
it sounds OK.  Then I start playing and all of a sudden the sound gets 
brighter and louder (I have envelopes going to both filter and amp).  This 
isn't right.  The envelope should not output higher voltages because I'm 
playing faster or more legato, yet it does.  I finally got around to scoping 
it and confirmed it.  With the exception of a little initial spike the ADSR 
outputs about 4 volts max.  Yet at certain settings if I play a fast trill I 
can push it up to about 6 volts.  Set A=0, D=6, S=7, R=4 and go into the a 
filter FM input and you'll see what I mean.

2)  If the Sustain level is set way up to about 10, then the Decay acts like 
an Attack.  I can set the Attack to 0 and move the Decay around to get 
various length attacks.  It seems to control the attack time from the normal 
4 volts up to a higher voltage which is set by the sustain level.  Strange.

3)  I can set Attack to 0, Decay to 0, and Sustain to 10 to get plain organ 
type envelope, yet the attack portion is too soft.  It's impossible to get a 
hard solid sound at this setting.

And I haven't even gotten into the somewhat artificial sound of the envelopes 
either because I need to compare side by side with another synth.  But they 
almost sound linear instead of exponential (even though I'm sure they're not) 
and don't seem to have a really good bouncy and punchy quality I like.  But I 
need to compare to others before I can say for sure what's going on here.

I've never experienced these things with any of my other synths.  Am I the 
only one dealing with these issues?

-Elhardt

Hmmm...

Just a few initial questions:

a) Are you *sure* these are the "Rev B" EGs (with the TRIG wire mod)?

b) What is the GATE source?

c) Are you using the TRIG input as well?

Paul S.

> 
> 1)  I patch up a sound and hit a key on the keyboard to trigger the sound and 
> it sounds OK.  Then I start playing and all of a sudden the sound gets 
> brighter and louder (I have envelopes going to both filter and amp).  This 
> isn't right.  The envelope should not output higher voltages because I'm 
> playing faster or more legato, yet it does.  I finally got around to scoping 
> it and confirmed it.  With the exception of a little initial spike the ADSR 
> outputs about 4 volts max.  Yet at certain settings if I play a fast trill I 
> can push it up to about 6 volts.  Set A=0, D=6, S=7, R=4 and go into the a 
> filter FM input and you'll see what I mean.
> 
> 2)  If the Sustain level is set way up to about 10, then the Decay acts like 
> an Attack.  I can set the Attack to 0 and move the Decay around to get 
> various length attacks.  It seems to control the attack time from the normal 
> 4 volts up to a higher voltage which is set by the sustain level.  Strange.
> 
> 3)  I can set Attack to 0, Decay to 0, and Sustain to 10 to get plain organ 
> type envelope, yet the attack portion is too soft.  It's impossible to get a 
> hard solid sound at this setting.
> 
> And I haven't even gotten into the somewhat artificial sound of the envelopes 
> either because I need to compare side by side with another synth.  But they 
> almost sound linear instead of exponential (even though I'm sure they're not) 
> and don't seem to have a really good bouncy and punchy quality I like.  But I 
> need to compare to others before I can say for sure what's going on here.
> 
> I've never experienced these things with any of my other synths.  Am I the 
> only one dealing with these issues?
> 
> -Elhardt
> 
> 
>  
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 
> 
>

Tony Karavidas writes:

>>I see all the same behavior (just popped it on my scope) except for #3. If 
the attack = 0, I get a 315uS rise time regardless of the other three pots 
(unless of course the release falls into the next attack phase.  I do see the 
sustain portion climb to 6.8 V under certain pot settings. Hmmm.<<

It's all very strange.  I was going by my ear on #3.  I just don't seem to 
get a hard attack but I haven't digitized it to see just how fast it is.  I 
did however try your UEG for comparision even though it's not a typical ADSR 
and I didn't experience any of these problems.

synth1@... writes:

>>Just a few initial questions:
a) Are you *sure* these are the "Rev B" EGs (with the TRIG wire mod)?
b) What is the GATE source?
c) Are you using the TRIG input as well?
<<

a) I bought all my 800's after the trig mod, so yes, they are all Rev B.  I 
have a total of 6 of them.  Just to be sure I didn't make a global mistake 
when I built my first batch, I just connected one from my second batch and it 
behaves the same.  Since Tony or Encore also sees these things, I have to 
rule out a mistake on my end.  That's the confirmation I wanted.  I surprised 
the rest of the list is silent.

b) My gate source is the Kenton Pro-2000.  It's set to a 5v gate, but behaves 
the same when set to 15v.

c) I'm not using the trigger input.

It's almost as if I'm playing on a touch sensitive keyboard when using my 
MOTM.  How I play affects the ADSRs and thus the brightness and loudness of 
the synth.  That of course shouldn't be the case.

-Elhardt

At 2:35 AM -0400 2002/05/08, elhardt@... wrote:
>Ever since I built my MOTM I haven't liked the way the envelopes worked, yet
>I've never heard anybody else comment on them.  I'm wondering why not.  Is it
>just me that experiences the following problems?

I have four 800s and I tried to replicate the problems you are 
seeing. I patched the envelope into the FM input of a 300 so it was 
easier to hear the envelope. I tested using the Gate out from a 
Pro-One into the GATE input of the 800s. I didn't put anything into 
the TRIG input.

>1)  I patch up a sound and hit a key on the keyboard to trigger the sound and
>it sounds OK.  Then I start playing and all of a sudden the sound gets
>brighter and louder (I have envelopes going to both filter and amp).  This
>isn't right.  The envelope should not output higher voltages because I'm
>playing faster or more legato, yet it does.  I finally got around to scoping
>it and confirmed it.  With the exception of a little initial spike the ADSR
>outputs about 4 volts max.  Yet at certain settings if I play a fast trill I
>can push it up to about 6 volts.  Set A=0, D=6, S=7, R=4 and go into the a
>filter FM input and you'll see what I mean.

I used A=0, D=6, S=7, R=4 as you suggested but couldn't find anything 
bizarre; the envelopes behaved as I expected them to. However if I 
use A=0, D=10, S=10, R=10 and trill rapidly then I can get a 
sustained 6.4 volts out. I wasn't expecting that.

>2)  If the Sustain level is set way up to about 10, then the Decay acts like
>an Attack.  I can set the Attack to 0 and move the Decay around to get
>various length attacks.  It seems to control the attack time from the normal
>4 volts up to a higher voltage which is set by the sustain level.  Strange.

I get this one too. If I set A=0, D=10, S=10, R=0 then the envelope 
hits 4 volts almost instantly and then exponentially decays UP to 5 
volts over a period of around 15 seconds. If D=0 then the decay UP to 
5 volts is almost instantaneous.

>3)  I can set Attack to 0, Decay to 0, and Sustain to 10 to get plain organ
>type envelope, yet the attack portion is too soft.  It's impossible to get a
>hard solid sound at this setting.

Hmmm, mine sound snappy enough to me. I usually don't even use A=0 
because I find  it too snappy at that setting. Maybe there's some 
extra resistance in your Attack pot (it's not 0 ohms when fully CCW). 
If I set my Attacks to greater than 0 then my results are much closer 
to yours.

>And I haven't even gotten into the somewhat artificial sound of the envelopes
>either because I need to compare side by side with another synth.  But they
>almost sound linear instead of exponential (even though I'm sure they're not)
>and don't seem to have a really good bouncy and punchy quality I like.  But I
>need to compare to others before I can say for sure what's going on here.

They sound exponential to me. The only thing I miss is a really long 
attack time, 20 seconds would be nice. If I ever find some good 5 Meg 
log pots I might try replacing my Attack pots.

>
>I've never experienced these things with any of my other synths.  Am I the
>only one dealing with these issues?

I never noticed these 800 oddities until you mentioned it. I'm glad 
you brought it up, you're certainly not alone.

I'm definitely seeing the same behaviour Scott describes.  I can't decide if
I see Elhardt's first problem or not.  It seems like the voltage output is
"lifted" partially if there's insufficient release time.

This seems to be a problem only for short attacks, below about 2 or so
(25ms).  The effects are less pronounced for non-zero attack and tend to go
away after about 2.

As for the second problem, it seems that there's the initial attack to
almost 5 volts, a short decay down to 4 volts, and then the actual decay to
whatever sustain level, whether its above or below the initial 4 volts, when
you have A=0.  Again, this is only a problem for short attacks; the longer
the attack the less pronouced this initial droop is.  With low sustains,
this "droop" also contributes to decay time, so if you set sustain=4 or 5
the minimum decay is about 25ms at A=0.

Elhardt, I suspect the "lack of attack" you hear is due to the second
problem.  The envelope is "decaying up" briefly, even when you have D=0.

I tried both keyboard gates and the pulse output from a '320.

                        ...Craig

----- Original Message -----
From: "Scott Juskiw" <scott@...>
To: <motm@yahoogroups.com>
Sent: Wednesday, May 08, 2002 10:08 PM
Subject: Re: [motm] Annoying MOTM envelope behavior


> At 2:35 AM -0400 2002/05/08, elhardt@... wrote:
> >Ever since I built my MOTM I haven't liked the way the envelopes worked,
yet
> >I've never heard anybody else comment on them.  I'm wondering why not.
Is it
> >just me that experiences the following problems?
>
> I have four 800s and I tried to replicate the problems you are
> seeing. I patched the envelope into the FM input of a 300 so it was
> easier to hear the envelope. I tested using the Gate out from a
> Pro-One into the GATE input of the 800s. I didn't put anything into
> the TRIG input.
>
> >1)  I patch up a sound and hit a key on the keyboard to trigger the sound
and
> >it sounds OK.  Then I start playing and all of a sudden the sound gets
> >brighter and louder (I have envelopes going to both filter and amp).
This
> >isn't right.  The envelope should not output higher voltages because I'm
> >playing faster or more legato, yet it does.  I finally got around to
scoping
> >it and confirmed it.  With the exception of a little initial spike the
ADSR
> >outputs about 4 volts max.  Yet at certain settings if I play a fast
trill I
> >can push it up to about 6 volts.  Set A=0, D=6, S=7, R=4 and go into the
a
> >filter FM input and you'll see what I mean.
>
> I used A=0, D=6, S=7, R=4 as you suggested but couldn't find anything
> bizarre; the envelopes behaved as I expected them to. However if I
> use A=0, D=10, S=10, R=10 and trill rapidly then I can get a
> sustained 6.4 volts out. I wasn't expecting that.
>
> >2)  If the Sustain level is set way up to about 10, then the Decay acts
like
> >an Attack.  I can set the Attack to 0 and move the Decay around to get
> >various length attacks.  It seems to control the attack time from the
normal
> >4 volts up to a higher voltage which is set by the sustain level.
Strange.
>
> I get this one too. If I set A=0, D=10, S=10, R=0 then the envelope
> hits 4 volts almost instantly and then exponentially decays UP to 5
> volts over a period of around 15 seconds. If D=0 then the decay UP to
> 5 volts is almost instantaneous.
>
> >3)  I can set Attack to 0, Decay to 0, and Sustain to 10 to get plain
organ
> >type envelope, yet the attack portion is too soft.  It's impossible to
get a
> >hard solid sound at this setting.
>
> Hmmm, mine sound snappy enough to me. I usually don't even use A=0
> because I find  it too snappy at that setting. Maybe there's some
> extra resistance in your Attack pot (it's not 0 ohms when fully CCW).
> If I set my Attacks to greater than 0 then my results are much closer
> to yours.
>
> >And I haven't even gotten into the somewhat artificial sound of the
envelopes
> >either because I need to compare side by side with another synth.  But
they
> >almost sound linear instead of exponential (even though I'm sure they're
not)
> >and don't seem to have a really good bouncy and punchy quality I like.
But I
> >need to compare to others before I can say for sure what's going on here.
>
> They sound exponential to me. The only thing I miss is a really long
> attack time, 20 seconds would be nice. If I ever find some good 5 Meg
> log pots I might try replacing my Attack pots.
>
> >
> >I've never experienced these things with any of my other synths.  Am I
the

> >only one dealing with these issues?
>
> I never noticed these 800 oddities until you mentioned it. I'm glad
> you brought it up, you're certainly not alone.
>
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

I suspect that this oddness is when the '800 is used with GATE only.

It probably has to do with the attack times less than the internal trigger pulse time. I would be
curios what occurs when a Pro-2000 is used with BOTH gate and trigger (you assign an AUX out to
VTRIG).

Also, I can see that if attack is very short (say 0) and decay is long (say 4 or more) when
sustain is at 10 it acts strangely. Think about it: what does this setting mean? How can you
"decay" when the sustain is at max? Where do you "decay" to? I suppose it should just sit at the
sustain setting (~+5V) and wait for GATE to drop, going into the release phase. But it may not.
However, I don't forsee a reason to redesign. It *is* a cheap, simple circuit.

Lastly, it you want just "organ" envelopes, use the MOTM-820 with GATE as you input.

Paul S.

At 7:41 AM -0500 2002/05/09, Paul Schreiber wrote:
>I suspect that this oddness is when the '800 is used with GATE only.
>
>It probably has to do with the attack times less than the internal 
>trigger pulse time.

That seems to be the ticket. Once I increase A from 0.0 to 2.0 then 
the problem goes away (i.e. the envelope instantly reaches 5 volts 
and stays there, it no longer decays slowly up to 5 volts).

>Also, I can see that if attack is very short (say 0) and decay is 
>long (say 4 or more) when
>sustain is at 10 it acts strangely. Think about it: what does this 
>setting mean? How can you
>"decay" when the sustain is at max? Where do you "decay" to? I 
>suppose it should just sit at the
>sustain setting (~+5V) and wait for GATE to drop, going into the 
>release phase.

That's exactly what I would expect it to do: decay from the attack 
peak of 5 volts down to the sustain level of 5 volts, a simple organ 
type of envelope. I wouldn't expect the envelope to slowly rise from 
4 volts to 5 volts while sustaining.

>But it may not.
>However, I don't forsee a reason to redesign. It *is* a cheap, simple circuit.

Consider it a unique envelope contour specific to the MOTM line.

As far as #2 and #3 problems, they are not of such a big concern to me.  For 
instance on #2, I can set the sustain level lower and be sure that decay is 
set to 0.  I noticed the problem probably by changing from one type of 
envelope to another and thought it strange that decay acted like attack.  
Somebody else seems to have noticed what I did (when sustain set to 10), the 
attack brings the envelope up to about 4 volts, then the decay basically 
decays in an upward direction (acting like attack) to the sustain level.

But my main problem is #1.  I will try to also use a vtrig from the Pro-2000 
to see if I can solve the problem that way.  If so then no need to worry 
about it further.  But if that doesn't work I don't know what to do other 
than drag my Doepfer upstairs and use its envelopes.  For those people who 
say they couldn't reproduce #1, I'm wondering whether your 800s are Rev A or 
Rev B.  You should really see the problem when playing relatively fast and/or 
legato.  It think the longer the release time the more obvious.  Playing like 
this pushes the output of the envelope higher and changes your sound 
according to where you've patched the envelopes to.  I almost get the 
impression that the release portion doesn't have time to drain the envelope 
back to 0v as it were, and the new note just builds ontop of the old one 
increasing the voltage.

I'll let you know whether a gate + vtrig solves the problem.

-Elhardt

scott@... writes:

>>I used A=0, D=6, S=7, R=4 as you suggested but couldn't find anything 
 bizarre; the envelopes behaved as I expected them to. However if I 
 use A=0, D=10, S=10, R=10 and trill rapidly then I can get a 
 sustained 6.4 volts out. I wasn't expecting that.<<

That's basically problem #1 I described.  If you trill fast or play fast at 
the first setting you should also see it rise up close to or beyond 6 volts.  
I guess with the extreme settings of 10 it's only going to become even more 
obvious.  I just wanted to keep the sustain away from 10 so I wasn't 
overlapping into problem #2.  I just wanted to be sure others experienced it 
so I know it's not just me.

-Elhardt