WE STAND AT SALUTE!!!!
this is awesome. a drop-in complete m-board pcb, with BOM, would be so huge......wow.
--- On Wed, 3/18/09, The Old Crow <oldcrow@...> wrote:
From: The Old Crow <oldcrow@...>
Subject: [yamahacs80] VCO153 project in board test phase
To: yamahacs80@yahoogroups.com
Date: Wednesday, March 18, 2009, 1:39 AM
Hey folks, its been a while, but I have this thing in testing right
now. This is an equivalent circuit to the IG00153. This differs from
my MOTM-style modular 153 oscillator in that it is strictly the VCO IC
with a ramp output, linear CV input, current bias input (FT) for octave
select and exponential modulation (vibrato) input. It can use the
original M-board FET and charge pump capacitor, or those can be removed
and local ones installed. I made this mainly to see about replacing
things at the chip level, but not relying on custom devices. It is 98%
SMT parts, with only 3 parts left through-hole for the moment (mainly to
swap things and see how the specs change). It no longer needs an input
offset trimmer, or external frequency compensation of the input summing
amp. The DIL-16 footprint in the middle of the board is used to install
it into an actual IG00153 socket. Generally it is low-profile enough to
fit between M boards (it does in my CS-50). It has internal temperature
compensation of the charge switch and comparator, making it much more
stable than the original device. The charge pump core circuit runs on
its own internal 10V reference supply.
Eventually I want to craft the entire M-board from standard circuits.
The waveshaper is done (it is the one I made for the 153 module). The
EGs are done. The filters are done. I know how to build the VCA, thats
next. In any case here is an image of the board, a bit larger than
actual size. More later...
http://www.cs80 com/VCO153_ pic.gif
Crow
/∗∗/
[Non-text portions of this message have been removed]