Dave Smith Instruments SYNTHESIZERS

hello!  this is my first post here...

so an annoying problem has popped up a few times with my desktop 
evolver:

When I've tried to create 808-style kick drums and deep dub-style 
bass patches using the two analog oscillators tuned to the same 
pitch (and with the amp output in "mono" rather than "stereo" mode), 
I get a slow sweeping phase cancellation that causes the volume of 
the sound to fluctuate in a roughly sine-wave-like pattern.  So as I 
keep triggering the sound over the course of say 30 seconds it will 
go through maybe one cycle of quiet and weak to full and deep.  This 
is annoying because I want to create some deep, low speaker-rattling 
kind of sounds.  And I know it's phase cancellation because it 
doesn't happen if I disconnect either output from my mixer.  And 
this is happening on sounds with no detuning, mod, filter split, or 
anything else I can think of that would cause phasing.  I guess the 
problem could be in my mixing board or monitor setup, but i've never 
noticed it with other low-pitched sources.  It seems that the 
problem is occuring in the summing of the left and right signal 
paths of the evolver.

Any ideas or solution?

Thanks!

Related question:  when the amp output is in "mono" mode, do both of 
the main outs on the evolver ouput the same thing?  In this case I 
should just be running one mono out from either the L or R ouput of 
the evolver to my mixing board. Problem is I like to use both stereo 
and mono patches in my liveset and don't want to constantly be 
plugging and unplugging that cable.  OK, I'm verging on answering my 
own question, but would still appreciate any help...



--- In DSI_Evolver@yahoogroups.com, "bebotalk" <ceg5@h...> wrote:
> hello!  this is my first post here...
> 
> so an annoying problem has popped up a few times with my desktop 
> evolver:
> 
> When I've tried to create 808-style kick drums and deep dub-style 
> bass patches using the two analog oscillators tuned to the same 
> pitch (and with the amp output in "mono" rather than "stereo" 
mode), 
> I get a slow sweeping phase cancellation that causes the volume of 
> the sound to fluctuate in a roughly sine-wave-like pattern.  So as 
I 
> keep triggering the sound over the course of say 30 seconds it 
will 
> go through maybe one cycle of quiet and weak to full and deep.  
This 
> is annoying because I want to create some deep, low speaker-
rattling 
> kind of sounds.  And I know it's phase cancellation because it 
> doesn't happen if I disconnect either output from my mixer.  And 
> this is happening on sounds with no detuning, mod, filter split, 
or 
> anything else I can think of that would cause phasing.  I guess 
the 
> problem could be in my mixing board or monitor setup, but i've 
never 

> noticed it with other low-pitched sources.  It seems that the 
> problem is occuring in the summing of the left and right signal 
> paths of the evolver.
> 
> Any ideas or solution?
> 
> Thanks!

1.  try turning on Osc Sync.  Thats the only way I know to keep the two 
analog osc's in phase with eachother.

2.  use just one oscilator and pan it center. You shouldnt need two osc. 
to simulate an 808 kick, as they were only single oscilators that were used.

Analog oscilators drift in phase - thats just their nature, and part of 
their desired character when creating synth sounds.  This is not so good 
when your creating drum sounds, however, which need to have more static 
phase relationships.

Tony


bebotalk said  on 7/15/2005 9:06 AM:

> hello!  this is my first post here...
> 
> so an annoying problem has popped up a few times with my desktop 
> evolver:
> 
> When I've tried to create 808-style kick drums and deep dub-style 
> bass patches using the two analog oscillators tuned to the same 
> pitch (and with the amp output in "mono" rather than "stereo" mode), 
> I get a slow sweeping phase cancellation that causes the volume of 
> the sound to fluctuate in a roughly sine-wave-like pattern.  So as I 
> keep triggering the sound over the course of say 30 seconds it will 
> go through maybe one cycle of quiet and weak to full and deep.  This 
> is annoying because I want to create some deep, low speaker-rattling 
> kind of sounds.  And I know it's phase cancellation because it 
> doesn't happen if I disconnect either output from my mixer.  And 
> this is happening on sounds with no detuning, mod, filter split, or 
> anything else I can think of that would cause phasing.  I guess the 
> problem could be in my mixing board or monitor setup, but i've never 
> noticed it with other low-pitched sources.  It seems that the 
> problem is occuring in the summing of the left and right signal 
> paths of the evolver.
> 
> Any ideas or solution?
> 
> Thanks!
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
>

Good points. Thanks.

--- In DSI_Evolver@yahoogroups.com, Tony Scharf <tony@m...> wrote:
> 1.  try turning on Osc Sync.  Thats the only way I know to keep 
the two 
> analog osc's in phase with eachother.
> 
> 2.  use just one oscilator and pan it center. You shouldnt need 
two osc. 
> to simulate an 808 kick, as they were only single oscilators that 
were used.
> 
> Analog oscilators drift in phase - thats just their nature, and 
part of 
> their desired character when creating synth sounds.  This is not 
so good 
> when your creating drum sounds, however, which need to have more 
static 
> phase relationships.
> 
> Tony
> 
> 
> bebotalk said  on 7/15/2005 9:06 AM:
> > hello!  this is my first post here...
> > 
> > so an annoying problem has popped up a few times with my desktop 
> > evolver:
> > 
> > When I've tried to create 808-style kick drums and deep dub-
style 
> > bass patches using the two analog oscillators tuned to the same 
> > pitch (and with the amp output in "mono" rather than "stereo" 
mode), 
> > I get a slow sweeping phase cancellation that causes the volume 
of 
> > the sound to fluctuate in a roughly sine-wave-like pattern.  So 
as I 
> > keep triggering the sound over the course of say 30 seconds it 
will 
> > go through maybe one cycle of quiet and weak to full and deep.  
This 
> > is annoying because I want to create some deep, low speaker-
rattling 
> > kind of sounds.  And I know it's phase cancellation because it 
> > doesn't happen if I disconnect either output from my mixer.  And 
> > this is happening on sounds with no detuning, mod, filter split, 
or 
> > anything else I can think of that would cause phasing.  I guess 
the 
> > problem could be in my mixing board or monitor setup, but i've 
never 

> > noticed it with other low-pitched sources.  It seems that the 
> > problem is occuring in the summing of the left and right signal 
> > paths of the evolver.
> > 
> > Any ideas or solution?
> > 
> > Thanks!
> > 
> > 
> > 
> > 
> > 
> >  
> > Yahoo! Groups Links
> > 
> > 
> > 
> >  
> > 
> > 
> >

Set the "Osc Slop" parameter to zero.

[The Evolver's analogue oscs are _not_ vcos, they shouldn't drift at
all if you do the above.]

-Miles
-- 
Do not taunt Happy Fun Ball.

That won't help imho. The analog oscillators drift even if slop is zero.

I'd use the digital Oscs for percussive sounds.


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

From: "Miles Bader" <miles@...>
To: <DSI_Evolver@yahoogroups.com>
Sent: Saturday, July 16, 2005 1:31 AM
Subject: Re: [Evolver] phase cancellation issue


> Set the "Osc Slop" parameter to zero.
> 
> [The Evolver's analogue oscs are _not_ vcos, they shouldn't drift at
> all if you do the above.]
> 
> -Miles
> -- 
> Do not taunt Happy Fun Ball.
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 
> 
>

2005/7/16, Stefan Trippler <doct@...>:
> That won't help imho. The analog oscillators drift even if slop is zero.

How do they do that?  They're digitally clocked.

-Miles
-- 
Do not taunt Happy Fun Ball.

2005/7/16, Miles Bader <snogglethorpe@...>:
> 2005/7/16, Stefan Trippler <doct@...>:
> > That won't help imho. The analog oscillators drift even if slop is zero.
> 
> How do they do that?  They're digitally clocked.

[Tho of course it's possible that "slop = 0" doesn't actually disable
the drift algorithm, merely reduces its effect to some minimum.]

-Miles
-- 
Do not taunt Happy Fun Ball.