Well, I certainly love the mods on my CS-50:
Bringing out the CVs and Gates, and a 5th, monophonic gate.
I derive the highest and lowest note from that externally, run it thru a log
converter, and control two V/Oct monosynths that double the lead and bass
line.
And I have 4 LEDs for the Gates (externally) that are increadibly helpful
for tuning the synth.
Also, I re-routed the Suboscillator Sine wave to the aftertouch->VCO path.
that way I can add sine vibrato by aftertouch, and still can use other
sources (like noise, or the synth's main output fed back to the external
input) for VCF and VCA.
Also, I bring out the Aftertouch, the Sub Oscillator, the PWM oscillator and
the Ring Mod oscillator for external use.
It's nice to sweep a VC Phaser by Aftertouch, or to do some VC stereo
panning along with the PWM ...
I wouldn't build any FX device into the synth, though. There's so many
differend FX boxes I want to try, so it's a good thing to have them
separately.
JH.
----- Original Message -----
From: <blchrr@...>
To: <yamahacs80@yahoogroups.com>
Sent: Tuesday, November 06, 2007 11:01 PM
Subject: [yamahacs80] Re: CS80 PSU mod-anyone ever done this?
fwiw, i went down the route of modding the cs80 with some external fx built
into the unit... (changing the Cs80 chorus for a dc-2 circuit and changing
the tremolo circuit for a PH-3 circuit)
it was a BAD idea, DO NOT mod classic synths, leave them as they are...
Fortunately i only modified (drilled for extra pots) the modulation panel, i
managed to source another modulation panel and am changing it back
completely to a standard unit...
My own fault... but my answer is DONT modify the Cs80, work with what you
have...
> ahhhh, thanks for the thought, JH. that makes sense. i would rather not
> pioneer a mod on a synth that is as rare as this, but it seems to be very
> sensible and almost simple. im envisioning nothing more than a 3-5 ft
> umbilical-style cord with a multi-pin connector that screws in(my trident
> console has one that would work perfectly), mounted in the base of the
> chassis, right where the PSU is now. then you could set the psu on the
> floor within a few feet of the base of the chassis(of course mounted in
> its own chassis!).
>
> i wonder, how much impedance could be lost between 8" and 5'? (i guess
> thats a question for my multimeter.)
>
>
>
> "JH." <jhaible@...> wrote: I've
> never done this (in fact, my CS-80 isn't even in my home yet), but I'll
> offer one thought nevertheless:
>
> The GND impedance may be a problem.
>
> Linear VCOs are very sensitive to small offset voltages in the low
> frequency
> range, so a voltage drop across the GND connection may be a problem. I
> have
> that theory, which isn't any more than a gut feeling right now, and may
> be
> totally wrong, that the slight coupling via voltage drop ∗inside∗ the
> CS-80
> may play a role in it's increadible lush-ness - then a longer GND path
> might
> turn the feature into a problem.
> But then again there's a servo sensing for the PSU regulation if memory
> serves - that would ∗allow∗ a rmote PSU (with sense and power wires both
> going thru the umbilical cord).
>
> JH.
>
> ----- Original Message -----
> From: "rj krohn" <r_j_d_2.phila@...>
> To: <yamahacs80@yahoogroups.com>
> Sent: Tuesday, November 06, 2007 7:31 PM
> Subject: [yamahacs80] CS80 PSU mod-anyone ever done this?
>
> hi folks, i wanted to ask why a particular mod has never been discussed,
> or
> done, to my knowledge on CS80's. hoping for some practical answers, to
> see
> if i consider should setting out on this.
>
> it seems like it would be relatively easy to detach the PSU from the
> CS80,
> and make it an external unit. im assuming that most(if not all) of the
> reknowned pitch instability/temperature issues were due to the massive
> PSU/input transformer. after seeing this firsthand, i see there are just
> two
> harnesses and a ground wire that connect to the rest of the synth. it
> seems
> like it would be pretty easy to take the PSU out, install 1 or 2
> connectors
> to adapt the harnesses to, and build an external box for the PSU. there
> cant
> be more than 16-18 total harness pins for the rails of the PSU. by now,
> im
> sure every cs80 in existence is a studio unit, and this wouldnt be too
> inconvenient, and could potentially help the stability. of course, the
> connector would have to be a screw-in type that could be well secured to
> the
> chassis.
>
> is there a reason this hasnt been done, or has this been covered already,
> and a terrible idea for some reason? thanks guys!
>
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Regards,
Rob Belcher
www.myspace.com/duplx
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