Inside a Moog Polymoog Keyboard

Discussions about anything analog, digital, MIDI, synth technology, techniques, theories and more.

Inside a Moog Polymoog Keyboard

Postby hfinn » Sat Sep 01, 2007 10:43 pm

I'm currently in the process of bringing back a Moog Keyboard back from the dead. A LOT of things were wrong with it, some stupid and some are still wrong.

I believe who ever had this before me was GOING to do a restoration on it and decided against it. And then proceeded to put it back together in a most clumsy manner. All the buttons were backwards, volume slider upside down, etc.

Here we have an overview with the top off.

Image

Close up of the TL board. Reference oscillator board (power supply in the background):

Image

Close up of the TC board. This is the filter board (The filter board for Vox Humana can be seen poking at the very bottom):

Image

Close up of the TR board. This is the VCF, Prog. Control board:

Image

This is what it looks like under the top three boards. These are the balance cards, bypass cards and mod cards. There is a card for every key.

Image
Last edited by hfinn on Sat Sep 01, 2007 10:57 pm, edited 1 time in total.
User avatar
hfinn
Expert Member
Expert Member
 
Posts: 1249
Joined: Fri Dec 10, 2004 3:21 pm
Location: Boston
Gear: http://soundcloud.com/heath-finnie

Advertisement:

Postby madtheory » Sat Sep 01, 2007 10:52 pm

ice pics! Thanks. It looks very well made. The style of the sliders is very like the Opus 3, which IMO was not as well made as this Polymoog appears to be. Good luck with the project.
User avatar
madtheory
Supporting Member!
Supporting Member!
 
Posts: 3366
Joined: Mon May 01, 2006 12:45 pm
Location: Cork, Ireland
Real name: Tomas Mulcahy
Gear: Fabreeze, Buck Owens Moog, Korg Warlock 9000, Roland Sultan of Brunei, Moog Ribald Cat.
Band: madtheory

Postby Tyler2000 » Sat Sep 01, 2007 11:46 pm

seriously, good luck. I hear that polymoog owners are afraid to move it even an inch for fear of breaking it.
so what do I put down here now?
User avatar
Tyler2000
Senior Member
Senior Member
 
Posts: 941
Joined: Wed Feb 22, 2006 4:31 am
Location: Huntsville, AL
Gear: HS-60, MG-1, CS-5, ESQ-1, CZ-101, DR-110, MR-10, MDP-40, EA-1, ER-1, ES-1, Trixer, SDS-9, Califorian 365, toys, guitars, ukes, etc.

Postby shaft9000 » Sun Sep 02, 2007 1:58 am

Good luck with that one. If you can get it working anywhere near 100% i'll be impressed and dumbfounded. It's a strange, quirky board.

Thanks for the noodies :shock:
2600.solus.modcan a.eurorack.cs60.JP8.Juno6.A6.sunsyn.volcakeys.jd990.tb303.x0xb0x.revolution.
999.m1am1.RY30.svc350.memotron

shaft9000.muffwiggler.com <- singles & mixtape
shaft9000.bandcamp.com <- spacemusic album
youtube.com/shaft9000 <- various synth demos and studies
User avatar
shaft9000
Supporting Member!
Supporting Member!
 
Posts: 2097
Joined: Tue Nov 14, 2006 3:13 am
Location: VanNuys, CA USA
Real name: Dave
Gear: ZF synchromesh 6-speed manual transmission

Re: Inside a Moog Polymoog Keyboard

Postby Tex » Sun Sep 02, 2007 5:35 am

[quote="hfinn"]I'm currently in the process of bringing back a Moog Keyboard back from the dead. A LOT of things were wrong with it, some stupid and some are still wrong.

I believe who ever had this before me was GOING to do a restoration on it and decided against it. And then proceeded to put it back together in a most clumsy manner. All the buttons were backwards, volume slider upside down, etc.


What's wrong with it, Did you fire It up? The 280a is much more reliable than people like to think and tend to associate it with the early serial number 203a's. Be sure to test the power supply or you may regret it if you don't.

-Tex
DSI PEK, Prophet 08(soon),Moog Voyager AE, Multimoog,Moog Liberation,Polymoog 203a,280a,Hammond D-100,E-100, Farfisa CCD w/ Leslie 825.
User avatar
Tex
Newbie
Newbie
 
Posts: 13
Joined: Sat Aug 18, 2007 6:09 am
Location: Kingsville, Texas

Postby Analogue Crazy » Sun Sep 02, 2007 2:49 pm

I bet the Polymoog Syntesizer has even more electronics inside. There is no wonder they can be tempremental.
A6 Andromeda, MS20 Mini, M500SP, DS-8, Motif 7, DX11,
User avatar
Analogue Crazy
Senior Member
Senior Member
 
Posts: 812
Joined: Sun Apr 23, 2006 5:31 pm
Location: Sheffield, South Yorkshire, UK
Real name: Rob
Gear: Alesis Andromeda
Korg MS20 Mini
Korg Micro Preset
Korg DS-8
Yamaha Motif 7
Yamaha DX11

Postby Bitexion » Sun Sep 02, 2007 8:31 pm

Wow. This is like synth porn. I'm getting hard. Look at *THOSE* circuit boards!
User avatar
Bitexion
Synth Explorer
Synth Explorer
 
Posts: 3610
Joined: Fri Apr 15, 2005 7:43 pm
Location: Drammen, Norway
Gear: Alesis Andromeda A6
Roland D-50
Yamaha Motif XF6
Roland Gaia
Alesis Ion
Analogue Systems modular
+various assorted bits&bobs

Re: Inside a Moog Polymoog Keyboard

Postby hfinn » Mon Sep 03, 2007 1:02 am

Tex wrote:What's wrong with it, Did you fire It up? The 280a is much more reliable than people like to think and tend to associate it with the early serial number 203a's. Be sure to test the power supply or you may regret it if you don't.


Well, lots of things. Some presets play louder than others, some not at all. ALL require you to turn the volume up much louder than you normally should to be able to hear it, The buttons were backwards (fixed), the volume slider was backwards (fixed), 5 L.E.D.'s needed to be replaced (also fixed), When doing the adjustments, the decay (low, mid and high) is reading 2.5v instead of the -3.64v it supposed to be (well out of reach of the trimmers). Through the MAIN output, any lower note you play retriggers the highest note you are holding down. That's an odd one :)

The power supply was the very first thing I checked (as it should always be) and the voltages coming off that are spot on.
User avatar
hfinn
Expert Member
Expert Member
 
Posts: 1249
Joined: Fri Dec 10, 2004 3:21 pm
Location: Boston
Gear: http://soundcloud.com/heath-finnie

Postby MrFrodo » Mon Sep 03, 2007 3:13 am

Do any of you know if those are (approximately) the same innards of the P-Moog synthesizer?
The greatest thing we ever have is the will to survive.

Rest in peace, Dr. Robert Moog.

http://www.ericbenjamingordon.com
http://cdbaby.com/cd/ebgordon
http://www.myspace.com/ericbenjamingordon
MrFrodo
Expert Member
Expert Member
 
Posts: 1052
Joined: Sun Oct 09, 2005 9:29 pm
Location: New York, NY, USA
Real name: Eric

Postby hfinn » Mon Sep 03, 2007 3:53 am

MrFrodo wrote:Do any of you know if those are (approximately) the same innards of the P-Moog synthesizer?


They are pretty much the same except the synth version has another board right under the front right panel, Also the board under the left panel is more involved. The top right board is also more 'busy' on the synth version:

Image

And for quick comparison, here is the keyboard version again:

Image
Last edited by hfinn on Mon Sep 03, 2007 4:42 am, edited 1 time in total.
User avatar
hfinn
Expert Member
Expert Member
 
Posts: 1249
Joined: Fri Dec 10, 2004 3:21 pm
Location: Boston
Gear: http://soundcloud.com/heath-finnie

Postby sizzlemeister » Mon Sep 03, 2007 4:22 am

Can you say HEAT-related problems? Yes, I think you can. Not to mention the number of caps in that thing that most definitely need replacing, and old first or second generation ICs? Oi!
User avatar
sizzlemeister
Junior Member
Junior Member
 
Posts: 219
Joined: Tue Nov 22, 2005 3:44 pm

Postby bigbadbarns » Mon Sep 03, 2007 7:48 am

I just restored my friend's Korg M500 ('Micropreset'). Some tard had beaten it up pretty badly then used housepaint to try and cover it up. So I sanded it back, puttied it up and resprayed it. looks awesome. AAAANYHOO, I WISH I'd taken a photo of the circuit board. It was INSANE. I've never SEEN so much shit jammed onto a board.

Which is unfortunate, because a few of the functions aren't working, and there's NO way I could even begin to comtemplate where the problem lies.
User avatar
bigbadbarns
Junior Member
Junior Member
 
Posts: 121
Joined: Sun Sep 19, 2004 2:33 am
Location: sydney, australia

Re: Inside a Moog Polymoog Keyboard

Postby Tex » Mon Sep 03, 2007 3:52 pm

[When doing the adjustments, the decay (low, mid and high) is reading 2.5v instead of the -3.64v it supposed to be (well out of reach of the trimmers).

Be careful when reading the sevice manual. It assumes your using an analog voltmeter instead of a dmm. It threw me off initially. How is that 203a doing. Is that a new one you just got?

-Tex
DSI PEK, Prophet 08(soon),Moog Voyager AE, Multimoog,Moog Liberation,Polymoog 203a,280a,Hammond D-100,E-100, Farfisa CCD w/ Leslie 825.
User avatar
Tex
Newbie
Newbie
 
Posts: 13
Joined: Sat Aug 18, 2007 6:09 am
Location: Kingsville, Texas

Re: Inside a Moog Polymoog Keyboard

Postby hfinn » Mon Sep 03, 2007 5:03 pm

Tex wrote:[When doing the adjustments, the decay (low, mid and high) is reading 2.5v instead of the -3.64v it supposed to be (well out of reach of the trimmers). Be careful when reading the sevice manual. It assumes your using an analog voltmeter instead of a dmm. It threw me off initially.


Yes, but every other adjustment was pretty spot on. So it seems weird that three trimmers in one section would be five volts off. So I'm trying to trace why they are so off.

Tex wrote:How is that 203a doing. Is that a new one you just got?


Thats actually not mine. Thats a picture of an old one I once had. I really want to find another synth version now as well.
User avatar
hfinn
Expert Member
Expert Member
 
Posts: 1249
Joined: Fri Dec 10, 2004 3:21 pm
Location: Boston
Gear: http://soundcloud.com/heath-finnie

Postby Micke » Mon Sep 03, 2007 7:02 pm

MrFrodo wrote:Do any of you know if those are (approximately) the same innards of the P-Moog synthesizer?


Note that the "synth-version" of the PM originally went under the name Polymoog keyboard. They later re-branded it Polymoog synthesizer when the 'preset-version' was introduced around mid 1978. So Polymoog keyboard can actually refer to either version.

As far as the "synth-version" is concerned, it'd appear the original version was (still is?) more common than the later version. The reason for that I think is that they built a lot more units of the original version.

Interestingly, the Keyboard layout for the PM was changed a couple of times prior to its final release to the public in late 1976; the prototypes ( ca. autumn 1975) had a 72 note C to B keyboard On the pre-production model (spring 1976) the keyboard changed to an F to E and "at the very the last minute (summer/fall '76), (due to feedback from the musicians who had been given prototypes) the keyboard received a final change to a 71 note E to D in response to requests for a bottom E to compete with guitarists! This involved yet another expensive tooling change at the factory."

This was one of the reasons it took so long before the PM hit the streets.


Image
Larry Fast in front of his gear during the recording of "Cords", fall 1977. Note the prototype Polymoog
(C to B keyboard) on the right. He used it for the first time on tour with Nektar in the spring of '76 and
then on PG's debut album (rec. in the fall of that year).
"The (Yamaha) CS-80 is a step ahead in keyboard control, and a generation behind in digital control" -- Dan Wyman, Jan 1979
User avatar
Micke
Synth Explorer
Synth Explorer
 
Posts: 2196
Joined: Sat Sep 18, 2004 12:50 pm
Location: Sweden

Next

Return to General Synthesizers

Who is online

Users browsing this forum: calaverasgrande, Google Adsense [Bot] and 15 guests