Emax

You're right Ted, I think I'm better off without this whole CV thing.
I only came this far because I read in the manual that it's supposed to accept any CV source between 0-10V so i figured the ground as reference (if I understood you guys correctly) might not be the issue, since I got it to work -sort of. Still, why would the manual claim ANY cv source and not say a thing about this issue.. nevermind, after I heard the the different LFOs with the internal filters I wasn't so impressed as to continue down this road. I have an external MS-20 filter which I find better sounding anyway! 

So thanks for all the advice and if you could elaborate on this modwheel thing I'd be really grateful! 

Cheers!

--- In emax@yahoogroups.com, Ted Summers <djtbs1@...> wrote:
>
> A little knowledge can be a dangerous thing.
> So you continue down this road of doing what is not recommended.
> I recommend you stop and get a meter before you burn something up.
> If you burn up the circuit or kill the Emax, don't come complaining!!!
> 
> Ted
> 
> 
> 
> On Fri, Mar 2, 2012 at 2:02 PM, zrennaya <zrennaya@...> wrote:
> 
> > **
> >
> >
> >
> > Okay I think I missed the 0-10V part in the manual...I checked now and
> > it's there, so my bad!
> >
> > So now I experimented with my CV source changing the gain on its DC opamp
> > and tried to stay on the positive voltage side. Unfortunately I don't have
> > a multimeter so I just checked the tolerance of the pedal input on the
> > recalibration page and I only used values between the two tolerance limits.
> >
> > When the recalibration asks for minimum value I can reach Pre:0999 Post:_
> > , if I go below that, that's where my CV signal starts to act like the DATA
> > slider. As for the maximum value, I can only do Pre:0927 Post:2.
> >
> > So I calibrated it to these values and if I don't let the CV source go
> > beyond the two limits it actually works, but the resolution is rather
> > steppy, I'm guessing it's because of the Pre:0999-0927 calibration. So my
> > external sine LFO is okay, ramp down is okay-ish but ramp up can only go up
> > to a certain rate, after that it disappears, I guess because the sample and
> > hold ic can't sample it anymore with this resolution.
> >
> > I checked the calibration of the right wheel and it goes from
> > Pre:0947Post: to Pre:0334Post:2 which seems to be a much higher resolution.
> > Actually this popped up another question: I calibrate the right wheel and
> > then I assign it to filter cutoff but it wouldn't open and close it all the
> > way! If I set the initial filter cutoff value in filter setup to 0, the
> > wheel's lowest position closes the filter all the way but it won't open it
> > all the way up at the highest position, I have to set the initial value to
> > around 40 and that's where it happens, but then it won't close it all the
> > way at the lowest position. Can anyone clue me in? Cheers
> >
> > Sorry for my grammar, I'm from eastern Europe..
> >
> >
> > --- In emax@yahoogroups.com, el macaco <elmacaco@> wrote:
> > >
> > >
> > > The manual says the pedal takes 0-10 volts, so the problem is the
> > negative voltage.
> > >
> > > The service manual says you can input a voltage to the tip of the plug
> > 0-9 volts, or it can be a fedal that varies resistance from the tip to
> > ground.
> > >
> > > try it with a voltage source that only goes 0-5 and see if the same
> > trouble occurs.
> > >
> > >
> > >
> > >
> > >
> > >
> > > To: emax@yahoogroups.com
> > > From: jammie.emma@
> >
> > > Date: Fri, 2 Mar 2012 17:31:44 +0000
> > > Subject: Re: [emax] Re: Emax pedal input and control voltages
> > >
> > >
> > >
> > >
> > >
> > >
> > > i thought that it was when using a pedal
> > >
> > > if using another device to send cv into the pedal cv then you are asking
> > for
> > > trouble its not that kind of cv
> > >
> > > the cv from another device say modular synth will be ground and the cv
> > > voltage 0-10v
> > >
> > > you will damage the cv circuit
> > >
> > > if you want foot control from external device then just use midi
> > >
> > > ----- Original Message -----
> > > From: "Ted Summers" <djtbs1@>
> > > To: <emax@yahoogroups.com>
> > > Sent: Friday, March 02, 2012 4:54 PM
> > > Subject: Re: [emax] Re: Emax pedal input and control voltages
> > >
> > > > If I understand what was said, it was attempted to connect a different,
> > > > external device (not a pedal) to send a control voltage onto one of the
> > > > connections of the emax pedal input.
> > > > If I am wrong in what my understanding is, then ignore this post....
> > > >
> > > > Well, this is quite simply, an electronics question.
> > > >
> > > > The Voltage is coming out of 1 contact, and is used as the reference
> > by
> > > > the
> > > > IC.
> > > > As the wiper (pedal) is moved, it affects the return voltage in
> > reference
> > > > to the original voltage signal and (depending on the circuit) the
> > > > difference to ground as well.
> > > >
> > > > To inject a signal from some other device I wouldn't expect that to
> > > > necessarily work properly.
> > > > There is no guarantee that the other device's reference ground plane
> > is
> > > > the
> > > > same.
> > > > That scenario can create a difference in ground potential, a ground
> > loop
> > > > hum can result, bad value can result, etc.
> > > >
> > > > Is the other device using the same pin / connections for the ground and
> > > > reference?
> > > >
> > > > If not, there is potential for damage of both units as well, since you
> > > > could cause a short or overvoltage condition, exceeding the max voltage
> > > > limits of the ICs...
> > > >
> > > > Just something to think about...
> > > >
> > > > Ted
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > On Fri, Mar 2, 2012 at 8:30 AM, Chase Smith <plus_321@> wrote:
> > > >
> > > >> **
> > > >>
> > > >>
> > > >> My understanding is that the emax sends a cv out of the pedal input
> > maybe
> > > >> on the ring of a trs jack and that with the ground goes to the inputs
> > on
> > > >> a
> > > >> pot and the wiper output goes back in on the tip. I think it expects
> > you
> > > >> to plug in a different type of pedal, than something that would just
> > send
> > > >> a
> > > >> cv.
> > > >>
> > > >> I've asked about this here before because I had a problem (this is
> > with
> > > >> an
> > > >> emax II) trying to run the pedal input from a cv sequencer.
> > > >>
> > > >> Can anyone clarify this? I'll try to look up my old post later, but
> > now
> > > >> this has me curious about it. I do remember making a "pedal" with a
> > pot
> > > >> so
> > > >> I could just turn a parameter in realtime so I know that part is true.
> > > >>
> > > >> ________________________________
> > > >> From: zrennaya <zrennaya@>
> >
> > > >> To: emax@yahoogroups.com
> > > >> Sent: Friday, March 2, 2012 7:52 AM
> > > >> Subject: [emax] Re: Emax pedal input and control voltages
> > > >>
> > > >>
> > > >>
> > > >>
> > > >> Thanks jammie..again!
> > > >>
> > > >> So if I got you correctly, that particular ssm2300 has several
> > channels
> > > >> (I'm guessing 8), emax uses one for each of the onboard CV sources
> > and if
> > > >> they all work correctly it's only the pedal input channel that's
> > messed
> > > >> up
> > > >> and it splits its signal to the same output as the data slider for
> > > >> example,
> > > >> plus the sampling itself is also messed up on that specific channel?
> > > >>
> > > >> And sample and hold in this case means it's a basic AD converter and
> > on
> > > >> the analog processing end there's a same basic DA one, right? I mean,
> > the
> > > >> onboard controls are pretty smooth considering that but do you think
> > > >> their
> > > >> resolution is good enough for me to use an already D->A controller
> > and go
> > > >> A->D->A with them again? I'm talking about a higher-rate saw LFO.
> > > >>
> > > >> Thanks!
> > > >>
> > > >> --- In emax@yahoogroups.com, "jammie" <jammie.emma@> wrote:
> > > >> >
> > > >> > ssm octal sample and hold ic is damaged
> > > >> >
> > > >> > ssm2300 exchange for a smp08 by analog devices its a pin for pin
> > > >> replacement and has a better slew rate
> > > >> >
> > > >> > the pitch wheel the modulation wheel the volume slider and data
> > slider
> > > >> are cv sources the ssm2300 samples these and send the digital data to
> > the
> > > >> cpu which then processes the info and sends it to the smm2300 that
> > out
> > > >> puts
> > > >> the digital control data to a cv analog output for controlling the
> > filter
> > > >> or vca or panning
> > > >> >
> > > >> > you need to check the manual as i dont have it in front of me but
> > > >> > therte
> > > >> are several ssm2300 octal sample and hold multiplexer ic
> > > >> >
> > > >> > you need to check the manual for the 1 that samples the voltages
> > from
> > > >> the controllers
> > > >> > ----- Original Message -----
> > > >> > From: zrennaya
> > > >> > To: emax@yahoogroups.com
> > > >> > Sent: Friday, March 02, 2012 11:48 AM
> > > >> > Subject: [emax] Emax pedal input and control voltages
> > > >> >
> > > >> >
> > > >> >
> > > >> >
> > > >> > Hi everybody!
> > > >> >
> > > >> > I have another issue with my Emax, I've tried to use a CV signal to
> > > >> alter the filter cutoff -since there's only a sinewave internal LFO.
> > The
> > > >> manual says the pedal input receives standard CV signals but here's
> > what
> > > >> it
> > > >> does for me: even if the pedal input is not assigned to anything in
> > > >> preset
> > > >> definition, when I send a CV signal, the display jumps around
> > different
> > > >> submenus, on the main page it jumps around presets and when the
> > cursor is
> > > >> on some parameter to adjust, it changes the values, so basically it
> > does
> > > >> the same job as the DATA slider.
> > > >> >
> > > >> > The other thing is, this is a MIDI controllable CV source, so MIDI
> > CC
> > > >> values 0->127 means -5V -> +5V control voltage and even if I try to
> > > >> recalibrate the pedal input, when the cursor is over a parameter
> > value,
> > > >> when I turn the MIDI knob, there's no increment between cc values
> > 0-51,
> > > >> then some weird increment jumps between 52-59, then no increment
> > between
> > > >> 60-124, then major jump between 124-127.
> > > >> > Consequently, when I assign the pedal input to the filter fc, the
> > > >> > cutoff
> > > >> frequency is jumping around in the same fashion, while the submenus
> > jump
> > > >> around on the display at the same time.
> > > >> > Could anyone please give me some advice, or knows wether I'm doing
> > > >> something wrong or it's the emax's fault? Thanks a milion!!
> > > >> >
> > > >> >
> > > >> >
> > > >> >
> > > >> >
> > > >> > [Non-text portions of this message have been removed]
> > > >> >
> > > >>
> > > >> [Non-text portions of this message have been removed]
> > > >>
> > > >>
> > > >>
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > > >
> > > >
> > > > ------------------------------------
> > > >
> > > > Emax and Emax II User's Group Website
> > > >
> > > > http://www.silveriafamily.comYahoo! Groups Links
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>