MOTM

Paul walked me through this before and I didn't write it down. Stupid me.

I **still** can't get anything to sound right. Perhaps I don't understand
all of the labels on all of the panels well enough.

Most basic set-up. Hook VCO (sine, square, triangle, PWM) directly to amp.
Steady tone can control pitch (fine & coarse). Width affects PWM output,
but PWM knob does not affect output. Constant tone.

2nd most basic set-up. Put CV (Korg Prophecy-->Novation Bass Station Rack)
into VCO 1V/Oct. Pitch changes as expected. Constant tone.

The most basic synth (with no filters of course--Come on June 15th!).
CV into VCO 1V/Oct (as above)
VCO Sine into VCA CV
Gate (from BassStation) into EG GATE
EG OUT+ into VCA IN
VCA VCA OUT into amp
VCA Gain to zero (and all other values)

Sometimes I get sound all of the time with bizarre attacks and decays. I
tied the VCA Gain at zero and all other values. It is actually hard to
describe. It does seems as the gate is making it in from the BassStation.
The sound is always soft connected like this too.

Is it patched wrong?
Is a knob or switch the wrong direction?
IS the VCA or EG not working properly?

I've tried lots of combinations. It seems like the EG???

Also what is the VCO PWM modulation **supposed** to do? I thought it was
the equivalent of Depth.

Have I given enough information?

Thanks!
Todd

1. Make sure the CV Mod control on the VCA is turned up - this controls how
much the envelope affects the VCA gain. If it is off, and the VCA gain is 0
or less, you won't get anything out of the VCA.

2. PWM is an input, not an output. PWM (the knob) controls the amount a
signal plugged into the PWM jack affects the width of the pulse wave output.
So plug a LFO, envelope or something into the PWM input, turn up the PWM
knob, and listen to the signal out at the Pulse jack. The width of the pulse
at any instant is a combination of the Width knob (sometimes called initial
pulse width), and the PWM control signal.

Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...

> -----Original Message-----
> From: Tentochi [mailto:tentochi@...]
> Sent: Friday, May 14, 1999 4:04 PM
> To: MOTM Mailing List
> Subject: [motm] Still having possible ADSR problems
>
>
> From: "Tentochi" <tentochi@...>
>
> Paul walked me through this before and I didn't write it down. Stupid me.
>
> I **still** can't get anything to sound right. Perhaps I don't understand
> all of the labels on all of the panels well enough.
>
> Most basic set-up. Hook VCO (sine, square, triangle, PWM)
> directly to amp.
> Steady tone can control pitch (fine & coarse). Width affects PWM output,
> but PWM knob does not affect output. Constant tone.
>
> 2nd most basic set-up. Put CV (Korg Prophecy-->Novation Bass
> Station Rack)
> into VCO 1V/Oct. Pitch changes as expected. Constant tone.
>
> The most basic synth (with no filters of course--Come on June 15th!).
> CV into VCO 1V/Oct (as above)
> VCO Sine into VCA CV
> Gate (from BassStation) into EG GATE
> EG OUT+ into VCA IN
> VCA VCA OUT into amp
> VCA Gain to zero (and all other values)
>
> Sometimes I get sound all of the time with bizarre attacks and decays. I
> tied the VCA Gain at zero and all other values. It is actually hard to
> describe. It does seems as the gate is making it in from the BassStation.
> The sound is always soft connected like this too.
>
> Is it patched wrong?
> Is a knob or switch the wrong direction?
> IS the VCA or EG not working properly?
>
> I've tried lots of combinations. It seems like the EG???
>
> Also what is the VCO PWM modulation **supposed** to do? I thought it was
> the equivalent of Depth.
>
> Have I given enough information?
>
> Thanks!
> Todd
>
>
> ------------------------------------------------------------------------
> The Final Countdown is here!
> http://www.ONElist.com
> Join the "Star Wars" craze at ONElist.
>

Beyond what Dave has already said, and beyond verifying proper operation of
the EG (probably best determined by running the EG out into the FM input of
the 300), and beyond reminding you that the 800 EG has a different operating
mode with a gate only input, let me also suggest you might try to run a
ground wire between your two synths just in case you they aren't connecting
properly through the shield.

Just a thought
JB

In a message dated 5/14/99 12:57:40 PM, tentochi@... writes:

>Sometimes I get sound all of the time with bizarre attacks and decays.
> I
>
>tied the VCA Gain at zero and all other values. It is actually hard to
>
>describe. It does seems as the gate is making it in from the BassStation.
>
>The sound is always soft connected like this too.
>
>
>
>Is it patched wrong?
>
>Is a knob or switch the wrong direction?
>
>IS the VCA or EG not working properly?
>
>
>
>I've tried lots of combinations. It seems like the EG???
>
>

Thanks for the continued suggestions. I am finding out what is working, but
not finding the broken missing link (I am the nut behind the wheel though.).
Running the EG into the VCO FM worked as expected. The pitch changes rather
than the volume, ATTACK is inactive and DECAY functions as attack. Tried EG
+ and - and FM1 and FM2 (the latter two behaved identically) with EXP & DC
(as Paul originally suggested). I put the VCA in the loop and things are
amiss again. I get a constant tone whether a key is pressed or not. There
seems to be a peak in volume around 5 when turning the SUSTAIN knob--this is
strange to me. I still can't figure out the rest. I have tried all
combinations of CV MOD and GAIN.

Not quite sure I understand the ground wire test.

Are there some simple tests I can do to more or less isolate the VCA? The
Ring Mod portion seems to be OK.

BTW, I have not touched to pots yet on my VCO. I would believe this would
make a difference, right?

Eliminated VCO, EG, gate as problems....

--Todd

P.S. Me loves me MOTM. Come on 5/15>420 & 6/15>410!

P.P.S. Hey Paul! I think my soldering iron tips are starting to oxidize
while they are waiting to work again. Ha! Soldering withdrawal!!!!

> Beyond what Dave has already said, and beyond verifying proper
> operation of
> the EG (probably best determined by running the EG out into the
> FM input of
> the 300), and beyond reminding you that the 800 EG has a
> different operating
> mode with a gate only input, let me also suggest you might try to run a
> ground wire between your two synths just in case you they aren't
> connecting
> properly through the shield.
>
> Just a thought
> JB
>
> In a message dated 5/14/99 12:57:40 PM, tentochi@... writes:
>
> >Sometimes I get sound all of the time with bizarre attacks and decays.
> > I
> >
> >tied the VCA Gain at zero and all other values. It is actually hard to
> >
> >describe. It does seems as the gate is making it in from the
> BassStation.
> >
> >The sound is always soft connected like this too.
> >
> >Is it patched wrong?
> >
> >Is a knob or switch the wrong direction?
> >
> >IS the VCA or EG not working properly?
> >
> >I've tried lots of combinations. It seems like the EG???

In a message dated 5/14/99 7:33:19 PM, tentochi@... writes:

>Not quite sure I understand the ground wire test.

I believe there exists equipment where audio ground isn't connected to the
PSU ground so you would need to connect a wire across to both electrical
grounds of the different synths. I use banana jacks and can attest to the
need to make sure that you have a common ground between different systems,
and to the fact that (when not done) the systems will behave very weirdly!
But this is probably not the problem.

>Are there some simple tests I can do to more or less isolate the VCA?
>The

If you have a second audio source (preferably MOTM to help isolate the
problem) you can use your VCO in the subaudio range to control your VCA.
Try this simple patch:
1) Noise (MOTM 100 -- or use a signal from a second VCO MOTM 300 if you have
one) out to VCA IN.
2) VCO (MOTM 300) SINE OUT to VCA CV input.
Adjust VCO to a low frequency setting below the audio range.
3) Monitor the VCA output.

You should hear the amplitude of your signal source change at the rate
determined by the sine wave of the VCO.

>Ring Mod portion seems to be OK.

The pot I recently mentioned frying, was the CV MOD pot on my 110 -- the VCA
would work properly at low CV input levels, but cut out just a little above
it. As I said, it took a while to figure out where the problem lay.

>BTW, I have not touched to pots yet on my VCO. I would believe this would
>
>make a difference, right?

I don't understand this bit.

Happy hunting!
John B.

Got it! This last message got me to figurin'. I had the VCA and IN patch
cables reversed. Works great! I am now waiting for my first big
soldering/wiring mishap.

The indecipherable line was supposed to say something like I haven't trimmed
the pots on my VCO yet.

THANKS to ALL!
Todd

> -----Original Message-----
> From: JWBarlow@... [mailto:JWBarlow@...]
> Sent: Saturday, May 15, 1999 12:20 AM
> To: motm@onelist.com
> Subject: Re: [motm] Still having possible ADSR problems
>
>
> From: JWBarlow@...
>
>
> In a message dated 5/14/99 7:33:19 PM, tentochi@... writes:
>
> >Not quite sure I understand the ground wire test.
>
> I believe there exists equipment where audio ground isn't
> connected to the
> PSU ground so you would need to connect a wire across to both electrical
> grounds of the different synths. I use banana jacks and can attest to the
> need to make sure that you have a common ground between different
> systems,
> and to the fact that (when not done) the systems will behave very
> weirdly!
> But this is probably not the problem.
>
> >Are there some simple tests I can do to more or less isolate the VCA?
> >The
>
> If you have a second audio source (preferably MOTM to help isolate the
> problem) you can use your VCO in the subaudio range to control your VCA.
> Try this simple patch:
> 1) Noise (MOTM 100 -- or use a signal from a second VCO MOTM 300
> if you have
> one) out to VCA IN.
> 2) VCO (MOTM 300) SINE OUT to VCA CV input.
> Adjust VCO to a low frequency setting below the audio range.
> 3) Monitor the VCA output.
>
> You should hear the amplitude of your signal source change at the rate
> determined by the sine wave of the VCO.
>
> >Ring Mod portion seems to be OK.
>
> The pot I recently mentioned frying, was the CV MOD pot on my 110
> -- the VCA
> would work properly at low CV input levels, but cut out just a
> little above
> it. As I said, it took a while to figure out where the problem lay.
>
> >BTW, I have not touched to pots yet on my VCO. I would believe
> this would
> >
> >make a difference, right?
>
> I don't understand this bit.
>
> Happy hunting!
> John B.
>
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