Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

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Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

Post by HideawayStudio » Sun Mar 06, 2016 12:56 am

I thought I'd share something a little more unusual...

After much toil I have returned to life a rare late 60s Cordovox CG polyphonic all tube instrument having built a custom keyboard console to drive the large all tube divide down generator.

Like the 1939 Novachord the Cordovox is essentially a formant synth with 12 tube master oscillators and tube divide down chains cascading from them. Like the Novachord the Cordovox is set aside from a conventional organ in that it features genuinely polyphonic release. Unlike the Novachord's impressive array of 72 true tube VCAs, the Cordovox uses a technique closer to the release circuitry found in the Eminent 310U and ARP Omni but the effect is quite similar although the Cordovox only has one shared vibrato oscillator (and not six in the case of the Novachord!).

A 100 way harness was built and grafted onto a keybed rescued from an old organ cut down to 3 octaves and housed in a custom cabinet made by Chris Pretlove.

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The underside of the generator chassis is an insane mass of neon trigger bulbs, chaotic space wiring and custom integrated passives!!

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Its hard to think the 1939 Novachord has almost three times as many tubes as this wacky beast!!

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As well as the custom keyboard console the system has been modified to have variable speed and depth vibrato, a direct line output, and a tube overdrive stage. The PSU and tube PA is housed in a third cabinet.

Some live improvs during testing:
https://soundcloud.com/hideaway-studio/ ... -in-action
Last edited by HideawayStudio on Sun Mar 06, 2016 11:22 am, edited 3 times in total.

atkbg
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Re: Rare 1960s Custom Cordovox CG Tube Synth Awakens!

Post by atkbg » Sun Mar 06, 2016 1:22 am

8-|
I always love hearing your latest projects!

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Re: Rare 1960s Custom Cordovox CG Tube Synth Awakens!

Post by cornutt » Sun Mar 06, 2016 4:03 am

Interesting! So was this originally built into a console of some sort?
Switches, knobs, buttons, LEDs, LCD screens, monitors, keys, mice, jacks, sockets. Now two joysticks!

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Re: Rare 1960s Custom Cordovox CG Tube Synth Awakens!

Post by HideawayStudio » Sun Mar 06, 2016 11:12 am

cornutt wrote:Interesting! So was this originally built into a console of some sort?
The Cordovox CG series was originally a range of electro-acoustic accordions packaged in a similar manner to the Farfisa Transicord except that the early CG models were tube/valve based. In this case the accordion controller and umbilical was long lost leaving just the main generator and PA cabinets.

Fortunately the Accordion Controller is little more than a single bus bar keyboard and a series of "tab" switches so building a replacement synth style keyboard for the instrument was feasible albeit time consuming as there are 100 connections between the the keyboard and the generator assemblies. A donor keyboard assembly from an old organ was modified and cut down to three octaves and a series of switches mounted over it.

On hearing a demo of the instrument in original form I quickly got thinking that the electronic assemblies might well make the basis for a unique tube keyboard instrument.

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Re: Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

Post by LordVampyre » Sun Mar 06, 2016 5:49 pm

beautiful.

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Re: Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

Post by cornutt » Mon Mar 07, 2016 12:58 am

Holy c**p! You were supposed to wear that around your neck? :o
Switches, knobs, buttons, LEDs, LCD screens, monitors, keys, mice, jacks, sockets. Now two joysticks!

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Re: Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

Post by meatballfulton » Mon Mar 07, 2016 3:11 pm

No, the unit sat on the floor and a fat cable connected it to the accordion.

I knew a few guys who had Cordovox rigs. One had a stand for the accordion so he could play it like an organ. When driving the external unit, you didn't need to operate the bellows.

In the bottom photo you can see the connectors for the umbilical cable on the right.

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These are precursors to the MIDI accordions made today by Roland.

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I listened to Hatfield and the North at Rainbow. They were very wonderful and they made my heart a prisoner.

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Re: Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

Post by HideawayStudio » Fri Mar 25, 2016 7:18 pm

The beast is soon to be with its new owner for an exciting new life..

It certainly looks very pretty in the dark with around 65 tubes glowing away...

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Re: Rare 1960s Custom Cordovox CG Tube Polysynth Awakens!

Post by cosmolac » Tue Jun 16, 2020 9:57 pm

Hi, I actually just set out to build a cordovox synth and stumbled upon this which happens to be pretty much exactly what im doing! I was wondering if after all this time you still have the pinout for the controller umbilical cord it would be a huge help!

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