Found info on the 901D and a modular patch book

[CZ Rider]

Finally located a copy of an old book form the late 60's, by Ron Pellegrino. The title "An electronic studio manual, for use with R.A. Moog's voltage controlled, modular synthesizing equipment."
Seemed like a great book to find more info about, though I had never read any reference or reviews of this rare document. There were a few copies in the Philly area libraries. The original came with a 7" reel of audio tape, with demos of the sounds. Along with descriptions of the R.A.Moog modules, there was over 100 patch illustrations.
Very interesting book. It did uncover some of the mystery of the 901D Variable Waveform Output Stage. Untill now all I had was a fuzzy photo of the module, I could only guess what was written on the panel.


Here is what Ron Pellegrino describes the 901D as:




Ron also had the great idea of making rubber stamps of the various Moog modules to document his patches. Ron had access to the system sold to University of Wisconsin serial 1014. It has a very similar module configuration to the one I have here, so finding a patch book for a 1969 R.A.Moog was like finding gold. Here is one of his patched he describes as a scraping sound.


Great patch there! Not a typical VCO/VCF/VCA patch. I had hours of fun with just that one example.

[EricK]

Interesting find. Thanks very much for sharing!

[Goom]

Very cool, CZ! How did you find out about this book? Have you tried any of the other documented patches?

[CZ Rider]

Found the book by a google image search of R.A.Moog modules. As I was looking through this image came up. I noticed right away the 901D on the patch sheet.

Investigating further I found out this was a scan of a page from that book. Published by Ohio State University, it did not have an ISBN number. But was able to find there were copies located at the Philly Free Library, and a few Universities, like Penn, Rutgers, Cornell. A friend in Philly located it for me. So I made the trip to Philly to check it out.

I'm still on the first patch I tried. As Pellegrino describes, a scraping sound. Thought that was an interesting description, so I patched it up. I was thinking metalic scraping but is more like a bow scraping. An interesting patch because the single oscillator tone is first passed through a VCA controlled via a fast envelope. That is patched through the 905 reverb, set to fully wet sound. This tone is further shaped by an envelope controlled low pass filter. Kind of a gated reverb. Keith Emerson used a similar patch on most of his leads that first passed through the 905, then went on to the filter. Even when the 905 is set to a straight signal, it colors the tone somewhat.
I'll be trying every patch in the book eventually, but for now having fun with variations of patch 83.
Here is a small sample of that patch. First single notes where you can hear the gated type of reverb, then a 960 sequenced pattern.
Pellegrino Patch 83 demo MP3 download 2MEGS
Sounds a bit nasil with the full 905 only tone. Fun stuff!

[BrianK]

I'm fascinated by the 901C and D, mainly because they did not catch on. Seem very useful, in some ways, though not a core module to most.

I've seen at least 2 versions of the D - with different knob configurations. Look at the 1967 catalog cover - there's one there in plain sight that most people have never noticed!

I saw a 901C in person recently, but it seemed as if the graphics were less-carefully done, a little sloppy. And it was original, maybe they had just rushed the process a bit. Although all Moog modules have some variations, this one seemed less elegant and balanced than they usually are...

[CZ Rider]

Look at the 1967 catalog cover - there's one there in plain sight that most people have never noticed!

I have seen several photos of that particular 3U wide module. Can you verify that this is indeed a 901D? And can you post a close up of the panel labeling?
1967 catalog pic, second module from the left


Another photo from Manny Ghent's system, third module from the top left.


It does have the same ammount of controls and sockets, but seems strange that would also be 901D for several reasons. For one all R.A.Moog modules usually have a full description on the top of the module. The description looks more like only a few letters. Almost looks to me like the module number then possibly "mixer" or something similar. The 901D is actually a mixer too. But it does not read "901D Variable Waveform Output Stage" for certain on top. It also looks dual function like the top row of dials is duplicated on the next row. All four lables for those four knob functions are centered between the two. With what looks like a general description of each row, like xxxxxx A - xxxxxx B . And the bottom right and bottom left pairs of sockets almost look to read input and output. Does seem strange that the last knob on both rows is larger that the others. Almost indicating more importantce or a needed precision of that function. No idea what the center dial and socket pair is? Could just be an attenuator.

Also that configuration on the 1967 catalog would not make much sense. With only one 901 oscillator, there would not be much to modulate with a single 901 and 901D combo. It would be a single oscillator system. If you use the 901 for a LFO there is no other oscillator as a signal source. They did have a photo of a very similar configuration for the early "Synthesizer I" where that mystery module is replaced with another 901 making it a two oscillator Moog. (Might be a hint as to the function there as it was replaced with an oscillator.)

My guess is it could be a 901D, or more likely a 906 Impulse Generator, or even possibly the 962 two channel mixer. The 906 Impulse Generator would make the most sense in the pictured '67 catalog configuration. The 906 is described as both a signal source (Oscillator) and modulation source (Complex LFO). And had shaping controls similar to the 901D. Tough to guess without more info or higher resolution photos of that mystery module. The top of that module does not read "Impulse Generator" either ? Could be some funky dual oscillator module? Seems most likely it would be a signal/modulation source for a typical Moog configuration of a basic synthesizer.
I would like to see the close up of the panel to be sure.

Another system with that module was recently posted. May have to open up the photo if it clips off to view it, but the module on the top far right is another one. Even though it has strange deep dish knobs, that is the same module. That system was recently restored and sold, but that particular module was missing.

[stiiiiiiive]

[...]but the module on the top far right is another one.
[...]

The rightmost point I'm able to reach is a ring on a finger

[BrianK]

No, I have not closeups of that panel. But no matter which module is may be, it still lacks the information at the top. I'm only guided to 901D by the catalog listing itself - a module concurrent with what is offered in that very catalog. And it made more sense to have less information on the panel if it was related directly to the module next to it - a 901. And certainly some module panels don't follow "the rules" (nor do the inside PCBs); there are enough examples of strange combinations to prove a lack of consistency!

(As I'm sure you're aware, the catalog photos are just that - nothing being connected or demonstrated functionally. Two of the synths in the 1967 catalog - I think the Ic and IIc - are indeed the same synth/ribbon with different modules loaded in...)

I like the concept you propose of the larger knobs being functionally significant (mixer?), but don't have enough info from the poor photos to know anything. It's quite hard to analyze and determine anything without more detail.

[BrianK]

Thinking on it being a 962 two-channel mixer; there's not much point in it being in that system (one osc) or the Manny Ghent rig (which is the Moog factory synth in a early stage) as he has too many oscillators to "handle".

I do love the sound of the 984 mixer as a general tone shaper, those tone controls make the Moog sound MUCH better... I even would love a one-panel single channel version to run audio through....

[BrianK]

Aha! Mystery solved - I pulled out the old 1967 catalog itself (which I think it one of the coolest Moog items ever made!) and it's not clear but fairly obvious the top of the panel has a small number followed by one word. Five letter word - almost certainly just MIXER. The three knobs have the same script of 0-10, as does the fourth with the larger knob. Below the knobs is a larger set of letters, almost readable, as CHANNEL 1 and CHANNEL 2.
Cannot read the letters below the knobs except the ones under the third knob, which says "BASS" - so likely Teble and Input just before it?

Why the brief module name at the top? With the simple functionality (and people would be familiar with the term), it seems "mixer" would suffice, compared to the more complex names of other modules. Although the 984 (four-channel mixer) is available inside the catalog simultaneously, it says clearly "FOUR CHANNEL MIXER", as usual.

So indeed, this is the first clear ID of the 982 two-channel mixer.

What's also odd about this setup shown on the 1967 cover - is that (before the CP panels became a standard item), the lowest half-size panel below the modules was always custom-built' with trunk lines, mixer, attenuators etc. On this very synth, they show 3 attenuators on the Left, followed by a simple 4-channel mixer. There is already "mixing" coming from the one osc, and a 4 channel mixer below - so all this module would offer is the Bass/Treble options (yet we already have a LPF and 907 Filter Bank on the synth, some serious tone control). It's a nice cover shot showing a variety of modules, but not clearly a very functional setup. This may be the reason the module is replaced with another 901 inside the catalog. (It would have been nice on the photo inside, as then they would have simply listed the module - and saved us all this work!)

Interesting to note - as you said, Michael - that the rare 901D and this rare 962 have exactly the same number of jacks and knobs...

[eben1000uk]

hey CZ - that patchbook sounds like an amazing find! i have an original moog 3c here in UK, i would love to see some of the patching ideas from the pellegrino book. any idea where i can find a copy!?!?!

[noddyspuncture]

My system came with a 901C - which would seem to be the first one ever made (of 12 units...!?) It has serial number 1001. And I can say it is very useful... and leaves the CP3 mixer free for other duties...!

I also have what seems to be the 905 Reverb prototype.... built (or rather throw together) on that peg board stuff.

Cheers,
TOM

[CZ Rider]

So indeed, this is the first clear ID of the 982 two-channel mixer.

Looks like the BMF has aquired an old Moog with that very mystery module on the far right/top of this photo they posted.

Perhaps Marc at BMF can get us a clear photo of the panel labling and layout.
Guessing there is some type of panning pot? (Could be those large knobs are for panning?) This is how the Aries AR-328 stereo output module works, with two channel ins/outs, where input 1 or 2 can be panned left/right for the final output.
I was making a 962 clone and guessed it would simply be 1/2 of the 984 four channel mixer. Especially since the 984 had two identical 2 channel boards behind the panel. So my guess was 10 dials or 5 per strip, with each channel having input 1 and 2, bass, treble, final output attenuator. And a pair of in/outs for input 1 and 2 with output A and B. I was able to get all that in a 1U module using those ARP type AB pots with the 1/8" shafts.
My 982 clone panel, on far right:


Would like to see the original. These are AC coupled mixers and intended for audio only. Unlike the CP mixers that can handle both audio and DC mixing. Still, two channels would be usefull as a final output stereo mixer or mixer with a send/return with added tone coloring.

[BrianK]

Hoping to get pics of this from the BMF... it's a donated system from a University in their own state! Roger Powell's keyboard looks cool next to it. No word on its functionality, but all Moogs were built well and certainly restorable.

[Kevin Lightner]

Lots modded in that system.
Interesting. Even has a joystick.

Nice to have the mods done to the noise source in this pic (2nd from left, top tier) :