Crumar Composer -1982    Weight = 37 Lbs. Number manufactured = 500? MSR = $1500

User Manual:
Reset Proceedures: N/A
Operating System code: N/A
MIDI or other control protocol: N/A
Software related Links: N/A
Patches or knob settings:
Circuit Overview: below
Scematics/Service Manual:
Common Service Issues/Tips: below
Parts Sources: Keys knobs semiconductors misc
Uncommon chips/modules used: M110B1 keyboard processor, TMS3617NS mult.octave keyer/tone gen., CEM3310 EG's, CEM 3320 VCF's, CEM3330 VCA's, 4- TDA1022 BBD's
General Info Links: Big Blue Wave or My review immediately below:

My review of the Crumar Composer, 6/27/2007
These are a rare machine. Maybe 500 built? I see there were a couple
serial series U1 and U2 and I've seen only up to 200 something in one
and mine is 166 in the other. Someone wrote who had U2 00171.  I just
won (3/09) U2 190 it appears and it's a rust bomb and may wind up in
the scrap category (UPDATE: I fixed the thing and managed to get it even
looking fairly good!)   Anyway these sound GREAT! There is a
mixer for the 4 sections and bender for monosynth only and mod for all
other sections' vibrato. (with speed knob right there by the wheel) I
don't know what the 'touch dynamics' knob does. There is no velocity
on this thing. Two busses on the keyboard but one is for monosynth
and one for the others. Not for calculating velocity. ANd no AT
strip sensor or anything so..I dunno yet on that. Schematic anyone?
Also it has a breath input (tubing goes directly in) which can be
switched to give volume control for either poly or mono synth section.

Anyway, the review of sounds/features per section:

1) Performer sounding strings pretty much save the cool eq of the
performer of course. But at least the same kind of quality for the
tones it does have and a decent eq sweep and 8' 16' 'stops'.

2) 4 great preset organ tones plus percussion stops with master volume
and decay knobs. Overall organ 'sustain', a release envelope. It's
all paraphonic with retrig on all notes off but wow. Great BBD leslie
emulator that speeds up and slows down like the real thing. And nice
tone selection.

3) Polysynth is at least as nice as the ARP omni's I think overall. I
dunno that ARP filter is awful cool sounding I think. But the curtis
CEM3320 is ok too in it's own way and there is one of them shared
again with eg retrigger when all notes are lifted. CEM3310EG, and
CEM3330vca. These same three chips are in the mono section also. But
on the poly section there are three presets...a nice piano enveloped
sound and a more brassy sound and a more tweaky synth sound... and
then you can select 'free' which means you program it with the knobs
for ADSR, amount (invertable like Korg Delta etc.) and
cutoff/resonance. Anyway in the oscillator control section there are
two oscillators and both can be dropped an octave with a switch and
one can be detuned up or down a fifth or like that. Also second
oscillator can be muted. You can select between square and saw for
both independently.

4) Monosynth is one oscillator. But you have more waveform
types..pulses and triangle added and also you can vary footage from
32' to 4' I think it is. PORTAMENTO amount is very useful for
creating sounds where the lead lage the other parts. This thing can
sound very phat for a divide down based unit!

This is a tremendously undersaught unit it seems to me. They were
rare and at the end of an era..the year before MIDI. And the DX7.
Wish list? Oh...independent lfo for the monosynth? (oops..this was
before I realized it had finger vibrato! Just wiggle the finger and
you can have vibrator that is set at the rate you wiggle!) But I'm really
looking forward to recording with this thing! -Bob

Circuit Overview:
      Four part machine with lead synth, polysynth, organ and string sections. It has two classic 74LS221 based Crumar "DCO" units. One can be controlled by the pitch knob of osc2. These generate a hf clock signal that drives the TMS3617NS chips. They are paired (front and back of the interconnects) in octaves. The furthest right do the lowest octave and on up to the highest on the left. The chip 'pairs' are wired in parallel on the inputs from the keyer circuts under the keyboard. The REAR 4 chips are clocked to OSC2 and the FRONT 4 are clocked to OSC1. 6 transistors in front of each osc1 chip are the current to voltage converters for the output signal it appears. Since no schematic is available I took the time to make a pinout of the chips at least as you see in link above. But these chips generate 16', 8', 5 1/3', 4', 2 2/3', and 2' signals for the great organ presets, the strings and the poly synth section.
     A totally separate buss operates the M110 Monosynth chip used in Siel Mono etc. The analog boards are sandwiched with the control panel boards in obvious order. (ie. mono on left and poly on right where the controls are). I've taken time to document all the interconnects also below pretty much btw. Each analog board though contains a Curtiss CEM3310 EG, CEM3320 VCF and CEM3330 VCA and the controls on the front for them can be assigned either to poly OR mono but not both. Sadly unlike the Trilogy, there aren't pots on each preset so you can customize them easily. But the mono ones are pretty useful! The poly ones... could have been better I think but anyway a great monster analog! It even has touch vibrato which is initiated by a Piezo sensor attached to the left 'standard'. The plastic leg under the keyboard. You wiggle the keyboard and it induces some voltage there.
This machine has a breath control input for the solo synth OR polysynth in for an actual piece of tubing. The sensor is built in! This may be the first like that. The circuit apparently is an oscillator whose frequency varies as you put pressure into the 'diaphram' that the tubing fills. The bottom of the diaphram has conductive foil on it. and it apparently changes the capacitance of a gap in the circuit board! Near as..I can figure!! I haven't dissected it. If someone does that correct me. Probably the oscillator though feeds a frequency to voltage converter that controls a vca?

Service Tips:
      In the middle of fixing one of these rarities that has lots of switch/pot damage for starters plus many broken keys. Movement is similar to Siel's Fatar manufactured movements but with two springs below and correspondingly more complex plastic extenstion that holds them in place and moves them when key is pressed. I've plastic welded the broken off bushing holders underneath the keys on my DK80 and will do the same on this one it appears.

OK, now for the REAL STUFF! I finally (6/11) got motivated to delve into documenting some things so that people with repair issues can much more easily track the problem down since no schematics seem available anywhere. First in general, the mainboard in the bottom there has on the left, the bbd's for the string effect. Moving right another bbd used in the leslie simulation. And then the Monosynth M110 keyer/generator. And the TMS3617 chips that are the keyers for the polysynth section. Chips on opposite sides of the interconnect row down the middle there are wired with their inputs in parallel. That's because they are responding to the same key information and are acting on it simultaneously to create the two oscillator polysynth. The classic crumar dco's are in the rear of them there with trimmers to set pitch. (74LS122 chips being used as relaxation oscillators).

Lots of strange parts. I usually have most of the semiconductors save tone generators. I found some switches that will retro for the strange French 14 pin ones with "D" shafts though instead of round.
Contact Sound Doctorin'


1- 5 1/3'  output to transistor buffer
2- 4'      output to transistor buffer
3- 16'     output to transistor buffer
4- Sustain bias.  9V until key pressed.where it dips to near ground.
5- V+ (12V with 10ohm fuse resistor on Composer)
6- G keying input (These lines dive to .7V or so then gradually rise when *that* key is pressed.  
               If OTHER keys are pressed the voltage goes back up to 11.5Vish)
7- G#  "" ""
8- A  "" ""
9- A# "" ""
10- B ""  ""
11- HIGH C "" "" (When used.  Otherwise wired to +12V supply)
12- Reset out 
13- 2 mhz clock in
14- Ground/ V-
15- 1 Mhz Clock out.  4V to 11V or so trough to peak.
16- Reset in
17- C keying input
18- C# "" ""
19- D  "" ""
20- D# "" ""
21- E "" ""
22- F  "" ""
23- F# "" ""
24- Stab. in  (Voltage set by a transistor/resistor circuit at 4.8V or about there. )
25- Stab. out
26- 8'     output to transistor buffer
27- 2'     output to transistor buffer
28- 2 2/3' output to transistor buffer

Interconnects in Crumar Composer MAINBOARD

J1 pin #     Designation
 1     Poly Vibrato (to middle of poly mod wheel pot)
 2     Gate  _||_ (high when holding key)
 3     NC
 4     Detune OSC2 pot
 5     NC
 6     -4V approx (rear tune pot)
 7     +4V from Power supply brown wire
 8     NC

J2 - J5 are between the TMS3617 chips.  The High C is on the far LEFT.  These go to the keyer circuits under the keyboard

J6 pin#
3- Signal Ground
4- Osc2 Saw
5- Signal Ground
6- Osc2 Saw (+1 octave)

J7 pin#
1- Ground
2- +12V
3- Ground
4- -12V
5- Signal Ground
6- Osc 2
7- Signal Ground
8- Osc 2 (+1 octave)

J8 has 4 coax's going to left pins of poly control interconnect

J9 pin#
1- Organ Percussion 4' (Low = on to pin 6 of second interconnect from right rear)
2- Organ Percussion 2 2/3' (low = on from pin 5 of "" "")
3- Organ Percussion decay envelope (pin 1 of 1st interconnect on right rear)
4,6 - nc
5 - Gate (Active low)

J10 pin#
1- orange coax to pin 2 of second interconnect from right front panel
2- dark green coax to pin 5 of right most interconnect on right front panel
3- low if organ preset #1
4- ""  "" #4
5- ""  "" #3
6- ""  "" #2

J11 pin#
1- +12V
2- NC
3- Leslie speed (Slow = 12V, Fast = 0V)
4- All Organ output (w/perc and leslie)
5, 6- -12V
7- Organ decay envelope
8- Leslie switch (On = high)

J12 Is keyboard scanner.(note)  Pin 1=B through 10=D.  THen for some reason 11=C and 12=C#

J13 pin #
1- Mono priority.  Left = high, Right = low
2- Portamento (A saw wave with short time for fast portamento but goes to ~6VDC in the middle and 3VDC by the end)
3- Ground
4-6 are not used

J14 pin#   Mono footage select
1- low if 8'
2,3- NC
4- low if 32'
5- low if 4'
6- low if 16'

J15 pin#
1,2- NC
3- mono gate (to pin 9 left analog)
4- touch mod (from P979)
5- to mod board bender out
6- Solo tune pot CV

J16 pin#
1- Mono Pulse
2- Signal Ground
3- Mono Saw
4- Signal Ground
5- Mono Square
6- Signal Ground
7- Brown wire to left analog pin 4 (?)

J17 Pin#
1- 8' switch (low = on) 
2- String out (green coax)
3- 16' switch (low = on)
4- Signal Ground
5- nc
6- brown wire to pin 4 of right most interconnect (?)

J18 pin#
1- -12V
2- +12V
3- Ground
4- nc
5- signal ground
6- String output to pin 7 far right panel interconnect

J19 pin# Keyboard scanner (octave)
1- Octave 1
2- Octave 2
3- Octave 3
4- Octave 4
5- High C
6- nc