Author Topic: Question re Clav (D6) HUM & Wiring  (Read 2335 times)

Offline zoooombiex

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Question re Clav (D6) HUM & Wiring
« on: October 15, 2013, 11:50:52 AM »
I'm restoring a D6 with the intention of making it as hum-proof as possible for gigging.  I know about the options for the preamp (shield box or clavinet.com replacement) and the clavinet.com humbucking pickups.  I was curious who has tried either of those and what their experience was.

Also, the power and audio lines in the D6 are literally tied together and run across nearly the entire board,  Normally, at least in other applications, you don't want audio and power lines running parallel as the power line will introduce noise & hum.  I was curious if anyone had re-wired a clav to address this and if they noticed any improvement from doing so.  I'm not sure I want to put another hole in mine, but in theory, you could put the jack all the way over on the left by the preamp and avoid running the power across the board entirely.  I was instead thinking of just un-bundling the power & audio lines and separating/insulating each of them from the other.  But I thought I'd check here before doing so.

Any thoughts are welcome!  Thanks!

Offline voltergeist

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Re: Question re Clav (D6) HUM & Wiring
« Reply #1 on: October 15, 2013, 01:01:45 PM »
Using a high-quality shielded cable for the long run of audio should help with any noise contribution from that run, without having to relocate the connector.
Restored or Overhauled: '65 A-model Sparkletop, '78 Suitcase 73, early-'75 Satellite 88, '81 MkII Stage 73, two '77 Mk1 Stage 73's, '74 Mk1 Stage 73
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Offline zoooombiex

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Re: Question re Clav (D6) HUM & Wiring
« Reply #2 on: October 16, 2013, 01:03:02 PM »
Thanks for the suggestion.  I have some good wire that I use to make instrument cables, and thought about replacing all the audio wiring in the clav with that.  But it looks like it's all original wiring so I was hesitant to tear it out unless it would actually make a difference.

And I guess if I'm doing that it'd be easy to separate the power wiring.  Maybe just run it in its own shielded tube.

Offline voltergeist

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Re: Question re Clav (D6) HUM & Wiring
« Reply #3 on: October 16, 2013, 01:47:44 PM »
I don't have enough experience with clavs to tell you whether or not it will make a perceivable difference.  I'd recommend removing the original wire carefully and keeping it so if there is no improvement the original can be put back in.  The shield of the cable needs to be grounded.
Restored or Overhauled: '65 A-model Sparkletop, '78 Suitcase 73, early-'75 Satellite 88, '81 MkII Stage 73, two '77 Mk1 Stage 73's, '74 Mk1 Stage 73
In Progress: 1 '78 Suitcase (2nd one), '70 KMC - Customized w/ Peterson 4x12, '77 Wurli 270

Offline yorgatron

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Re: Question re Clav (D6) HUM & Wiring
« Reply #4 on: October 16, 2013, 05:38:03 PM »
I wonder if it would just be easier to use a 9v guitar preamp pedal in place of the D6 pre-amp.  ???
Wurlitzer 206A, Hohner String Performer, Clavinet/Pianet Duo, C, D6, Elka X-55, RMI 300A Electra-Piano & Harpsichord, Korg MS-10 & MiniKorg, Arp Axxe & Omni I.
sold; Wurlitzer 200, Vox Jaguar, 4 different Fender/Rhodes Stage 73, Yamaha CP-35/SK-30 x 2, Elka Rhapsody 490, RMI 368X Electra-Piano & Harpsichord, Korg DW-8000, Baldwin Electropiano, Roland HS-60, Roland Alpha Juno 2, Roland Juno 6, Clavinet II, Moog Prodigy, Moog Opus 3, ARP Quartet.

Offline Cormac Long

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Re: Question re Clav (D6) HUM & Wiring
« Reply #5 on: October 16, 2013, 05:55:43 PM »
One point I'd make on the audio and power lines alongside each other.. if the D6 is being driven from a 9V battery, you should have an unadulterated perfect DC signal there that should only be generating interference when its turned or or off. Now if you're driving this from a PSU, even a regulated one, the DC signal will be letting off some interference.

That all said, an unshielded passive audio cable is somewhat prone to inducing interference from surrounding AC sources. A very noddy test solution would be to line some masking tape with a strip of alu foil and stick it over the wiring as it runs along the case. Also try to connect that shielding to the same pre-amp surrounds just to ensure there is a common ground. This will give you some level of a Faraday cage around the wiring and may measure an improvement in the noise level.