X Y controller...

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rarecomponent
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X Y controller...

Post by rarecomponent » Thu Feb 27, 2014 10:12 pm

Regarding the wedge shaped plug-in XY box..
How did it function...?
I notice two leads/ jacks and a Cinch Jones lead/plug...did it collect a voltage and then export it thru the two jack leads ( controlled by joystick ) ?

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BrianK
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Re: X Y controller...

Post by BrianK » Fri Feb 28, 2014 10:27 am

Indeed. It used the same CinchJones plug that was used for many Moog accessories (although early ones had the 3 prong version as on the early Moog systems). This voltage goes through the two resistive potentiomenters (one per axis) and then out to 1/4" plug. Fairly simple but the design of the machining and assembly was the nicely-executed part.

rarecomponent
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Re: X Y controller...

Post by rarecomponent » Fri Feb 28, 2014 11:28 am

Thanks for your help..I'm guessing the three pin CJ plug was for +12 and -6 v ? Have you any idea what voltage range the jack leads output ? I'm trying to find how it was wired but there is virtually no info anywhere on the XY controller.

Regards

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CZ Rider
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Re: X Y controller...

Post by CZ Rider » Fri Feb 28, 2014 2:46 pm

The 959 is an interesting controller. Read an interview with Bob about the mechanical challenge of getting the dual axis without any backlash. Would be nice to see the inside of how they accomplished this.
There seem to be two versions of the 959. The original square box and the wedge shaped box. The wedge box first appeared on the CEMS in 1970. Not sure about the origins of the square 959, but perhaps the earlier standard version.
Here is the square version.
Image
This looks to be a simpler design with zero volts for both axis at the left bottom. There are typical Moog rockers with selection of either full or 10% voltage scale.
A schematic might be similar to the Moog 1150 Ribbon Controller auxillary slider. This aux. slider is wired to the + voltage input and ground on both ends of a 5K pot. With the wiper connected to a 1K resistor out to the black plug. The 10%/full rocker would probably be for different resistor values. This does not seem to need the negative rail, just the positive and ground. Dead simlpe, just need to experiment with the various resistor values.
There was one auctioned off on VEMIA a while back with a little info about the function.
VEMIA auction of square 959

The wedge version looks to be a bit more complex, perhaps with some form of extra circuitry.
Image
If the calibration markings are correct this would seem to send both positive and negative voltages. The center position would be zero volts on both axis with final attenuators for scale of each axis.
Having never seen the inside of one of these, I would guess a circuit similar to the Moog reverse attenuator. A simple circuit with three transistors. Something like this might be employed on each axis to give a center of zero with both a positive and negative voltage swing. Followed by a simple panel mounted attenuator to set the scale. This type wedge design would require both positive and negative rails. Would be fun to also wire in an input to each axis so other CV's could be used other than just the single straight voltage.
The wedge looks to be a redesign of the simpler square 959, first intended for the CEMS that Bob and Joel Chadabe designed together.
The original CEMS 959's were auctioned off at VEMIA a while back.
VEMIA auction of wedge 959

Would like to see the insides up close, or a schematic. If I was building one, I would use that Moog reverse attenuator as a starting point. Would be double usefull to be able to route any CV through the X-Y reversable attenuators or just use a single voltage on each axis like the original.


EDIT:
Another interesting design of Bob's that involved more modern TL082 chips would be the Circon designed for Carlos.
Here is a link to the Carlos page with info and schematic:
Bob Moog designed Circon for Carlos
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rarecomponent
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Re: X Y controller...

Post by rarecomponent » Sat Mar 01, 2014 8:46 pm

Again....great stuff here CZ..and thanks for your input. .yes I agree with the reverse attenuators and I'm going down that road to start. Ive been pointed to XY controllers from Music From Outer Space however I want to keep all the modules and any plug ins as near to Moog spec as possible.
The only problem I for see is the centre tapped pot. Ive made this circuit and modified a standard pot by grooving the carbon track ...it works but I need to sourse a joystick pot for the X Y box.
I wonder how Carlos's X Y foot pedal functioned? Two pedals...yes
But one ????

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BrianK
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Re: X Y controller...

Post by BrianK » Sat Mar 01, 2014 8:54 pm

I'll see what I can find, I had some photos to tech the assembly of it, the box - and something to do with Bill Hemsath. I think the slanted wedge version is earlier, as it came with the CEMS system and others around 1969. Then you see the blue Minimoog-style rocker switches - and they may mean the square version is later.

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CZ Rider
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Re: X Y controller...

Post by CZ Rider » Sun Mar 02, 2014 1:05 am

rarecomponent wrote:The only problem I for see is the centre tapped pot. Ive made this circuit and modified a standard pot by grooving the carbon track ...it works but I need to sourse a joystick pot for the X Y box.
I wonder how Carlos's X Y foot pedal functioned? Two pedals...yes
But one ????
That center tapped pot schematic may very well be the last revision drawing used on 1974 and later model 55's. I have plenty of photos of the early reverse attenuators where is uses a standard 25K linear AB type J pot. Same with the drawing from the model 15, using a standard 25K linear. I have a few EML issue 10K linear center tapped AB pots. EML used these on their two way mod wheel and a few other EML circuits. While the dead band center would be nice, it should be noted that most did not have this.

Not sure after thinking about it, that circuit would work so well with the limited travel of a joystick. Usually somewhere around a 90 deg. or so travel. That reverse attenuator would need to be first centered, then you would not get the full ammount of travel in either direction. Still might work though. Depends or the value of the joystick pots and if they can be centered.

The Bob Moog designed circuit for the Carlos Circon might be a better chioce as it has implemented range and scale. And it works with +12/-6 voltage. Would be nice to see the real wedge X-Y controller schematic.

Bob did some really interesting alternative controllers over the years. The dual axis 958 is another one. The standard 958 had a large treadle, and from the photos I have seen the dual axis 958 is built on top of that controller.
There is a photo on Roger Luther's site of and early system with those dual axis pedals.
Image

The one photo I have showing detail of how this mechanism worked is from Max Brand's custom Moog. On this particular system it looks like the R/L axis was actually a Mallory rotary switch. Interesting!
Image

Looks like a "Lazy Susan" type rotary bearing flange is bolted on to the 958 treadle, with a more rubberized, non-slip treadle over top for the R/L movement. Can see the bearings in the swivel flange on the left X/Y pedal. This type setup would reduce any shear force on the pot or rotary switch shaft. The standard mechanism for up/down looks even more intense.
Funny how most associate Moog with keyboard controllers, when Bob made so many unique atlernative ways to control a synthesizer. Every early system came standard with a linear controller unless ordered special. With the linear ribbon, X-Y axis, and percussion controllers there were many options.
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BrianK
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Re: X Y controller...

Post by BrianK » Thu Mar 06, 2014 8:16 am

The original wedge-shaped 959 had very little circuitry inside it, but a complex system of mounting one pot to the shaft of the other. And ran on +12-6 from the power connector. They were aware of the limitations of the small axial turn but I think it compares to the output of most modules of the day.

rarecomponent
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Re: X Y controller...

Post by rarecomponent » Thu Mar 06, 2014 4:39 pm

But we still dont know what type of output these XY pedals delivered
.....obviously a CV voltage but what...??

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CZ Rider
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Re: X Y controller...

Post by CZ Rider » Sun May 25, 2014 12:55 am

Have some more info on the inside of the 959 square version. timmcg over at Muffwigglers took some photos of his 959 and gave the OK to post them here.
Thanks Timothy! :D
Image
Image
Very interesting design and simple. Would have never guessed it was a 1" by 3/16" L peice of aluminum cut to about 1/2" wide to make the dual axis work, with the one pot floating. This is drilled for the floating pot mount, and drilled and tapped with setscrew for the fixed pot shaft. An interesting part is the 7/16" round stock for the handle. This is side drilled for the 1/4" floating pot shaft with a bottom drilled and tapped setscrew to hold the position of the shaft. The fixed pot looks to have the same type mount as all the Moog pitch and mod wheels.

I tried to get most of the measurements from some photos by measuring the screen. 1/2" walnut sides. About 6" square outside and 2" high. Top face plate 5" square and a 1" square opening for the joystick.

The wiring is simple and has +/- voltage on either side of the pot with the wiper going to the switch. That switch grounds via two resistors for the different responses of full or 10%, either 1K or 9.1K, and returns the axis voltage. Guess you would center the voltage by positioning the pot shaft via those set screws. The pot travel might only be about 1/3 or so of the full range, so some room for adjustment. Probably 25K or 100K linear pots, but will have to experiment to be sure. Timothy stated this one has the 6 prong power plug, so the pots are probably centered for +/- 10 volts.
Interesting design. I read somewhere Bob Moog said it was a challenge to get the X-Y movement without any backlash or slop. Directly connecting to the pots with one floating is a brilliant way to do it.
Just ordered some aluminum round and L stock. And picked out some 1/2" black walnut I have here to cut up tomorrow. Even have some of those fixed type .062" brackets. Have to get busy and try to make one of these, now I know how they did it. Might want to mod mine with an S-trigger button though. :)
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rarecomponent
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Re: X Y controller...

Post by rarecomponent » Sun May 25, 2014 11:05 am

Excellent post CZ....

What a good way to solve a difficult scenario. Forget the dedicated
Joy Stick controller ...and finding one if your cloning. .!! Just use two potentiometers
Simple and clever.

On first impression the pots will have to have metal spindles for strength for sure. Ive got some ex military ones and hope I can find the values for the two required.

Going to need fine engineering for this but it will be a great controller.

Let us know how you go on with this project CZ. and again thanks for posting.

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CZ Rider
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Re: X Y controller...

Post by CZ Rider » Sun May 25, 2014 9:47 pm

I think those AB type J pots are a large part of the action. Those pot shafts are either hardened steel or stainless. I was able to source some 25K pots, but they had 1 1/2" long shafts. Sawing with a coping saw to reduce any damaging heat was like sawing through a shackle on a lock. Very hard steel and not aluminum like cheaper ALPS pots. Made to take abuse!

On a similar note we discussed the possible circuits for a joystick and using the Moog reversable attenuator schematic. I have since made a few of these and tried both a standard 25K and a center tapped 10K pot. The response with the 10K was similar and has a nice neutral area where there is no voltage bleeding through + or -. The 25K standard was like tuning an oscillator. There was a zero spot, but it was very precise. Neither gave me unity gain though? At full CW or CCW was still a slight bit attenuated and not the same exact voltage going in as what was comming out. Part of the design I guess. But very usefull, and the center tapped pot made it easier to dail in a zero effect.

OK, I started to try to make one of these 959's today. First had to get the wood. Had some 1/2" black walnut for just such a Moog project.
Image
I needed 11" across to get two pieces of 6" X 2" and two of 5" X 2".
Fire up the saw!
Image
Needed to make the fixed pot bracket. The stock Moog brackets are 2 1/4" wide with the mounting screws 2" apart. My brackets I made for the modular pot/brackets are 2" wide with an 1 1/2" apart mounting. So a little different.
Bracket in the flat.
Image
Needed to put this in a vise and hammer it with an auto body dolley to get the proper bend.
Turned out Ok?
Image
Test fitting the pieces.
Image
Need a 1" square hole in the 5" X 5" front panel.
Image
Hole cut and filed.
Image
Starting to look like a 959.
Image

I'll have to glue up the walnut box tomorrow, so I can sand and finish it. I placed an order for some 7/8" aluminum round bar stock for the handle. And some 1" aluminum L by 3/16" for the floating mount. All the hardware looks to be 4-40 including the set screws. Should be a challange to drill and tap the rest of this assembly. Have to drill a 1/4" hole in the joystick handle for the floating pot shaft. Then drill and tap the end for the 4-40 setscrew. The small L will also need two holes with a third one tapped. Very do-able though.
I'll post something after I get this aluminum stock I need.
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noddyspuncture
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Re: X Y controller...

Post by noddyspuncture » Mon May 26, 2014 7:06 am

Man after my own heart you are, Terry...! Great stuff...!!

Cheerz,
Tom

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CZ Rider
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Re: X Y controller...

Post by CZ Rider » Wed May 28, 2014 1:34 pm

Timothy was nice enough to make some measurements of the 959 and take some more photos.
Thanks again Timothy!
Interestingly the original AB type J pot is a 10K audio taper.
Image
I would have never guessed that type/value. Those are difficult to source in an OEM part. Guess they did not produce these type in large quantities. I ordered some PEC (Precision Electronic Components Ltd) type pots. They seem to be sutable replacements with stainless shafts similar in construction to type J pots.
Timothy gave the dimensions. My guesses were a little off. The 959 is 5 1/2" square and 2 1/2" deep. So I had to resize my clone to smaller but taller dimensions. The joystick is 3/8" diameter and a bottom of black painted particle baord about 5 3/8" square and 1/8" thick.
Here is my resized wood being glued together.
Image
And after drying a bit of sanding to radius the corners.
Image
Waiting on the aluminum stock now before I can do any more. Looks promising though!
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noddyspuncture
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Re: X Y controller...

Post by noddyspuncture » Wed May 28, 2014 2:06 pm

Can you build me one please Terry...!? :)

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