SergeModular

> signal into the back-end of the banana (effectively multing

everything

> together) connecting RESET and RANDOM. Yes it's a little strange.

Thank you for the help! I would have never figured this out. Works
like a charm. :)

> Since this is something people do a lot with their DTG's (the

oscillator/LFO

> thing) some customers request a switch put in... flip the switch,

it connects

> GATE and TRIG, and off you go. Saves a patch cord.

Yes, the pannel I picked up has the 'flip switch' What is the blue
(top output?)


The next issue I have with this system is a 'grounding issue'. From
research on the web it seems that Serge is famous for strange
grounding. On this 4 pannel system when all for pannels are
connected to a PS6 there is NO problem with grounding. When I take
the pannel off with the 2 channel mixer (that I use for the output)
And use the pannel with the UAP as the output mixer I get ground
loops on *all* the outputs of the system (even with nothing patched
together). This seems strange.

Thank you for all the help. :)

Donald

> The next issue I have with this system is a 'grounding issue'. From
> research on the web it seems that Serge is famous for strange
> grounding. On this 4 pannel system when all for pannels are
> connected to a PS6 there is NO problem with grounding. When I take
> the pannel off with the 2 channel mixer (that I use for the output)
> And use the pannel with the UAP as the output mixer I get ground
> loops on *all* the outputs of the system (even with nothing patched
> together). This seems strange.

I'd like to second a request for info on Serge grounding issues. Could
someone knowledgeable give the non-EE types among us some basic tips?
Like, what, exactly, is a "ground loop"? I have some problems with my
recently-acquired used Serge as well. Sometimes (it's hard to
characterize when) things like oscillator frequency are very sensitve
to disconnected systems - even, e.g., the location of my hand! This is
very disconcerting. It's not just a matter of letting the system "warm
up", either. The other main problem I have is that my SEQ8 often
outputs a non-steady voltage (when not clocked!).

I've just gotten an oscilloscope, so I can start nailing down just what
it is I'm seeing. But it's tricky when the behaviors are not 100%
reproducible.

Thanks,
Bob Hearn
bob@...

> --- In SergeModular@y..., dbauer847@y... wrote:
> > The next issue I have with this system is a 'grounding issue'.

From

> > research on the web it seems that Serge is famous for strange
> > grounding. On this 4 pannel system when all for pannels are
> > connected to a PS6 there is NO problem with grounding. When I

take

> > the pannel off with the 2 channel mixer (that I use for the

output)

> > And use the pannel with the UAP as the output mixer I get ground
> > loops on *all* the outputs of the system (even with nothing

patched

> > together). This seems strange.
>
> I'd like to second a request for info on Serge grounding issues.

Could

> someone knowledgeable give the non-EE types among us some basic

tips?

> Like, what, exactly, is a "ground loop"?

Roughly speaking, you'll experience a ground loop any time you
connect two or more devices where each device has a different
ground (reference voltage). The ground loop will be audible
as a slight hum at 60 Hz. Let's say you have another synth
you are trying to process with the Serge. Because they have
different power supplies and each is plugged into a different
place, the grounds may not match, and you'll experience hum
in the signal path. The same problem if you're
plugging the Serge into a second device, such as a mixer.

Fortunately there is an easy solution if you route all I/0
through an external mixer (I assume you have plenty of individual
channel outs or aux sends to use for this purpose.)
Then you only have to make sure the grounds of the mixer and the Serge
match: all other devices are conditioned through the mixer.
For this purpose, there is a black-coded "ground" jack on the
back of the Serge power supply. You first need to find a special
"grounding plug" (this is a female banana plug attached to
a thin strip of metal designed to fit underneath a screw. I got
one from Rex, and I've never lost it, so I don't know offhand
where to order something like this. Can anyone find a picture
on the web?) Now find the screw on your mixer's back panel
which is closest to its own power supply (which should be near the
ON/OFF switch) Unscrew it slightly and attach the metal strip on the
grounding plug underneath the screw. Screw the grounding plug back
down. Now patch the Serge power supply's "ground" jack to the mixer's
grounding plug and voila! Serge/mixer share the same ground =
No more problems with hum!

What else -- sometimes there is a slight bleed-through
of the oscillators and especially the clock inside the Wilson
delay. This should not be confused with hum because you can
affect this by changing the unused oscillator frequencies.
Be sure to set the frequencies of oscilators you're
not using to maximum frequency, or somewhere
up above the audible range.

Other power distribution problems are not necessarily ground
loops, because ground loops are associated with hum.
If you accidentally patch outputs into outputs or
do anything to cause a significant drain on the power supply,
you can get all kinds of weird crosstalk, especially with DC
control voltages. THe best solution is to quickly
unpatch everything and start over. Usually doing weird
things with feedback (such as taking the audio mixer's output
and patching to one of the inputs, turning the gain just below
self-oscillation for a cool distortion effect) can't really
cause a drain on the power supply.

Happy patching...
--Harvey