I see, it's the other way around. That's why the signs for positive and negative open wide on both sides! So there's no attenuation to - and + (only at 0) and it's not amplification either.
How do you call that then?
Yes, I noticed the peaks of gain on out jacks during patching!
And Rex has warned me about places on the Serge, that can give high peaks.
What is the range of HZ for DC and AC?
I don't dare to give an answer myself, since DC can overlap AC.
I only now that our range of hearing lies between 500 hz and appr. 20 khz.
Yesterday I found some explanation about coupling on the internet.
It's states that DC is directly given, but with AC there's a capacitator in the way.
You say: "adjust that difference". What do you mean by that?
Which in Buchla system also means that you need different kabels.
This way of patching can be very handy, but it also limites the freedom of experimentation.
How do you call that then?
>No. And yes.But I believe, it depends on the type of VCA, exponential or linear, if it can produce extra gain.
>The incoming signal doesn't get attenuated when you turn the pot >either CW or
>CCW. The signal is fully attenuated (=0) when the pot is at its >center position.
>Turning the pot either way "opens" the signal more and more, until >you arrive at
>the full CW- or CWW positions, where the signal reaches its maximum >level, or
>the inverse thereof.
>But I'm sure you knew this; you just misplaced the word >"attenuated". :-)
Yes, I noticed the peaks of gain on out jacks during patching!
And Rex has warned me about places on the Serge, that can give high peaks.
>They 'could' or they 'can', yes.This is tricky!
>In this case, no.
>AFAIK, most attenuator pots on a Serge system do not provide for >extra gain,
>except where it makes more sense (VCA's, etc.). In that case, it's >called...
>Gain. Note however that "gain" also doesn't necessarily mean there >will be a
>possible greater gain than the original signal. Amplifying a signal >[in a
>modular synth] can be a tricky business... what with those >vulnerable speakers.
>In other words: an attenuator pot allows you to manually set a >signal between
>'nothing' and 'all', but not 'more'. A gain pot *could* potentially >make the
>signal larger, but not necessarily so. It depends on the >application. The
>electronic circuitry behind both is totally different. An attenuator >is (mostly)
>a passive device, whereas a gain circuit is an active device: it >amplifies a
>signal, and sometimes it can amplify above unity gain (=bigger than >the
>original).
What is the range of HZ for DC and AC?
I don't dare to give an answer myself, since DC can overlap AC.
I only now that our range of hearing lies between 500 hz and appr. 20 khz.
>DC can be fluctuating too. A LFO comes to mind...I now understand that you can hear DC as well. I didn't know this under till now. Always thought it's a cv, so sub-audio only.
>Look at it this way: AC (Alternating Current) fluctuates around the >zero axis.
>DC doesn't.
>When an AC signal isn't fluctuating *centered* around the zero axis, >it has as
>DC component (offset), which is mostly A Bad Thing.
>To make matters more complicated, a DC signal can be "shifted" >around and about
>the zero axis as well. This is what the SB buffer can do (with the >-5/+5 pot).
Yesterday I found some explanation about coupling on the internet.
It's states that DC is directly given, but with AC there's a capacitator in the way.
You say: "adjust that difference". What do you mean by that?
>When in the audio range, there is no correlation to what you hear >when a signalThis is not easy. I look in Wikipedia, but it only touches on AC and DC and such, but doesn't talk about the things I need to know. Beside that AC and DC linked with synths it seams almost impossible to find on the internet! I'm going to search for a good book on this subject.
>is AC or DC. A triangle audio wave sounds exactly the same when it's >either DC-
>or AC-coupled (respectively: above or below the zero axis, or >centered around
>that axis).
>When the signal is sub-audio, and it is used as a modulation source, >it makes a
>big difference. However, in the world of Serge, you can easily >adjust that
>difference by shifting that low frequency up or down. Again, the >Scaling Buffers
>come to mind...
>I understand where your confusion comes from. And Serge's paradigm >of being ableI agree with you; it's definitely one of the strong points of the Serge. But on the other hand it's important for the us, the makers to know what their doing. I mean outputing a signal below 500 hz result in silence! As soon as you patch it into f.e. a cv in of a NTO, you hear the signal again!
>to shift signals at will doesn't make it easier.
>I'm not very good at explaining this, though. Perhaps you could look >up a few
>things in Wikipedia ?
Which in Buchla system also means that you need different kabels.
This way of patching can be very handy, but it also limites the freedom of experimentation.
>It can be dauntingly complex, yes. See above about the Serge >paradigm. But this'morning Roel,
>is one of the strengths of a Serge system: it allows you to freely >"play with
>signals", regardless if they're DC or AC. A Serge system doesn't >really make a
>difference between audio and low frequencies. It's just... a signal, >and it is
>left up to you as to what to do with those signals. This in sharp >contrast with
>a Buchla system, where audio and CV are strictly separated.
--- In SergeModular@yahoogroups.com, "roelelec" <r.steverink@...> wrote:
>
> Hi Guy,
>
> So the In signal gets attenuated when you turn the knob to the plus (CW) and
of course inverts when you turn it ccw.
> Isn't it strange that this particular processed pot doesn't amplify like all
the others do? I mean in the Gold book and other places there's written that
processed pots can attenuate, amplify and or invert a cv voltage!
They 'could' or they 'can', yes.
In this case, no.
AFAIK, most attenuator pots on a Serge system do not provide for extra gain,
except where it makes more sense (VCA's, etc.). In that case, it's called...
Gain. Note however that "gain" also doesn't necessarily mean there will be a
possible greater gain than the original signal. Amplifying a signal [in a
modular synth] can be a tricky business... what with those vulnerable speakers.
In other words: an attenuator pot allows you to manually set a signal between
'nothing' and 'all', but not 'more'. A gain pot *could* potentially make the
signal larger, but not necessarily so. It depends on the application. The
electronic circuitry behind both is totally different. An attenuator is (mostly)
a passive device, whereas a gain circuit is an active device: it amplifies a
signal, and sometimes it can amplify above unity gain (=bigger than the
original).
> I always thought DC voltage (non-fluctuating) is always below zero (subaudio)
and AC voltage (fluctuating) above zero (audio), but I discovered that DC
voltage can be in the plus also!
DC can be fluctuating too. A LFO comes to mind...
Look at it this way: AC (Alternating Current) fluctuates around the zero axis.
DC doesn't.
When an AC signal isn't fluctuating *centered* around the zero axis, it has as
DC component (offset), which is mostly A Bad Thing.
To make matters more complicated, a DC signal can be "shifted" around and about
the zero axis as well. This is what the SB buffer can do (with the -5/+5 pot).
> Is there no correlation with the hearing sound?
When in the audio range, there is no correlation to what you hear when a signal
is AC or DC. A triangle audio wave sounds exactly the same when it's either DC-
or AC-coupled (respectively: above or below the zero axis, or centered around
that axis).
When the signal is sub-audio, and it is used as a modulation source, it makes a
big difference. However, in the world of Serge, you can easily adjust that
difference by shifting that low frequency up or down. Again, the Scaling Buffers
come to mind...
> I mean on the NTO, the sinus has a black ring which means it outputs between
-2,5 and + 2,5 volts
AC-coupled, yes.
and triangle and saw have blue rings which indicates 0 - +5 volt.
DC-coupled :-)
Does this mean -2,5 - 0 of the sinus is DC which as soon as it goes higher then
zero, it turns into AC? Or is this nonsense!
> Can you please explain this!
I understand where your confusion comes from. And Serge's paradigm of being able
to shift signals at will doesn't make it easier.
I'm not very good at explaining this, though. Perhaps you could look up a few
things in Wikipedia ?
> Thanks, yes now I understand what scaling in this context means and does! But
I suspect that scaling on another funktion is more complex than that.
It can be dauntingly complex, yes. See above about the Serge paradigm. But this
is one of the strengths of a Serge system: it allows you to freely "play with
signals", regardless if they're DC or AC. A Serge system doesn't really make a
difference between audio and low frequencies. It's just... a signal, and it is
left up to you as to what to do with those signals. This in sharp contrast with
a Buchla system, where audio and CV are strictly separated.
> Which panels does your Serge contain?
Less than it matters. Or more than it matters. :)
_g
>
> Cheers,
>
> Roel