VDA-1, VAC-1 Umbilical

videocrew · « **on:** 16 Jun 2008, 05:01 am »

I'm considering making my own umbilical to run between my VAC and VDA. I can't justify $100 bucks for the Revelation gizmo since I don't even think I paid that for either component on the used market.

Here's what I'm thinking. Dusty let me know what size plug I need and I found a Switchcraft plug that will do the job. I was thinking about Venhaus unshielded twisted pair for the cabling. I would think shielding would be great, but since there is nowhere to ground the shield to, I don't know if it would be worth it. I'm also considering pulling the plugs out of the VDA and VAC and hardwiring the cable between them (they are both cracked, as they seem to do a lot).

Any thoughts? Comments? Suggestions? Worth it?

Thanks for your advice guys.

erimille · « **Reply #1 on:** 16 Jun 2008, 02:36 pm »

Quote from: videocrew on 16 Jun 2008, 05:01 am

I'm considering making my own umbilical to run between my VAC and VDA. I can't justify $100 bucks for the Revelation gizmo since I don't even think I paid that for either component on the used market.

If you got the VDA and VAC for $100 each, you got a steal

Quote

Here's what I'm thinking. Dusty let me know what size plug I need and I found a Switchcraft plug that will do the job. I was thinking about Venhaus unshielded twisted pair for the cabling. I would think shielding would be great, but since there is nowhere to ground the shield to, I don't know if it would be worth it. I'm also considering pulling the plugs out of the VDA and VAC and hardwiring the cable between them (they are both cracked, as they seem to do a lot).

Any thoughts? Comments? Suggestions? Worth it?

Thanks for your advice guys.

I'll let Dusty follow-up on specifics, but just to i'm very interested in hearing how this turns out. My VAC is cracked as well and have been thinking of something similar. I've been in discussion about sending it back for repair, but I managed to finally get it working. I'm liking it so much in my system, I don't want to take it out even for a few days to get it fixed

fyi, if you go with the plugs, I've read that Moser part number 502-760 Switchcraft DC plugs 2.5MM X 5.5MM black may be the right fit [1]

--e

[1] http://forums.slimdevices.com/showthread.php?t=40923

videocrew · « **Reply #2 on:** 16 Jun 2008, 02:44 pm »

Hmm, that link was informative. Maybe I could pull both the jacks, hardwire in a shielded cable, and ground the shield to the IEC ground on the VAC-1...

How sensitive is the VDA to being placed very close to the VAC? Any benefit to separating them? Or would stacking be a problem?

erimille · « **Reply #3 on:** 16 Jun 2008, 05:07 pm »

Quote from: videocrew on 16 Jun 2008, 02:44 pm

Hmm, that link was informative. Maybe I could pull both the jacks, hardwire in a shielded cable, and ground the shield to the IEC ground on the VAC-1...

How sensitive is the VDA to being placed very close to the VAC? Any benefit to separating them? Or would stacking be a problem?

fwiw, i haven't found any combination of placement to be a problem with the VDA and VAC. On principal alone, i'd suggest as much distance as possible, but I've been able to detect no degradation in performance having them on top of each other.

If you decide to build an umbilical cable (hardwired or plugged), I'd suggest something slightly shorter than the stock one might be better.

--e

videocrew · « **Reply #4 on:** 16 Jun 2008, 05:33 pm »

Yeah, I was considering stacking with about a footlong umbilical between them. I wish I had the right size allen wrench to crack the VAC-1 open and take a look inside to get a better idea.

erimille · « **Reply #5 on:** 16 Jun 2008, 05:50 pm »

Quote from: videocrew on 16 Jun 2008, 05:33 pm

Yeah, I was considering stacking with about a footlong umbilical between them. I wish I had the right size allen wrench to crack the VAC-1 open and take a look inside to get a better idea.

Get the allen wrench. The VAC-1 is perhaps the cleanest design I've ever seen. It's actually quite attractive

--e

videocrew · « **Reply #6 on:** 16 Jun 2008, 05:58 pm »

I mean... transformer+box+connectors.

Hard to mess that up

snoogly · « **Reply #7 on:** 17 Jun 2008, 08:00 am »

I had a serious issue with VDA / VAC placement recently. The VAC was making very audible 'crackling' noises, and audio was jumpy. I had to move the VDA to a lower shelf on the rack.

Very odd, as they worked fine right next to each until I got new amps - ciaudio amps in fact!

videocrew · « **Reply #8 on:** 17 Jun 2008, 01:44 pm »

That's weirtd...
I don't have any hum issues yet, sounds like some sort of digital amp nastiness.

erimille · « **Reply #9 on:** 17 Jun 2008, 01:54 pm »

Quote from: videocrew on 17 Jun 2008, 01:44 pm

That's weirtd...
I don't have any hum issues yet, sounds like some sort of digital amp nastiness.

Hmm... I'm not sure about that. I'm using a PS Audio HCA-2. There is no hum issue related to the placement of the VDA / VAC. In fact, the VDA, VAC and VPC-1 passive are all quietly sitting in a row right on top of the HCA-2 making very nice music together

--e

CIAudio · « **Reply #10 on:** 17 Jun 2008, 03:24 pm »

Our products are designed to be placed side by side. Stacking is not recommended as the power transformer will be directly above/below the sensitive analog circuits and can induce noise.

Quote

I had a serious issue with VDA / VAC placement recently. The VAC was making very audible 'crackling' noises, and audio was jumpy. I had to move the VDA to a lower shelf on the rack.
Very odd, as they worked fine right next to each until I got new amps - ciaudio amps in fact!

This sounds like a cable/shielding issue...not a placement problem.

videocrew · « **Reply #11 on:** 17 Jun 2008, 03:34 pm »

Thanks Dusty. Any thoughts on shielded vs. unshielded cable for the umbilical? It would be no more than 1 foot, so I don't know if it's critical, but you know a lot more than me, which is why I buy your stuff instead of the other way around.

CIAudio · « **Reply #12 on:** 17 Jun 2008, 04:14 pm »

Quote

Thanks Dusty. Any thoughts on shielded vs. unshielded cable for the umbilical? It would be no more than 1 foot, so I don't know if it's critical, but you know a lot more than me, which is why I buy your stuff instead of the other way around.

You cannot shield it if only making a new cable (there are only 2 wires).
If hard wiring, you can connect the shield to the the VAC-1 chassis...the chassis is connected to AC ground.

videocrew · « **Reply #13 on:** 17 Jun 2008, 04:17 pm »

Well then stay tuned for the first VAC with a grounding post modded in and a rather odd looking umbilical...

some young guy · « **Reply #14 on:** 17 Jun 2008, 04:24 pm »

FWIW I made my own silver umbilical when I ran these units, years ago. I hard-wired them without any shielding. The results were excellent compared to the original set-up IMHO. I also ran them side by side.

PurplePanties · « **Reply #15 on:** 30 Jul 2008, 10:10 am »

I'm bumping this up because I've just bought myself a VDA-2 and VAC-1 combo

and am wondering if it's worth upgrading the stock Umbillical, but do not want to spend $100 on the Revelation cable because it's $100!!!! Can you guys recommend something a little cheaper?

Can I also ask, a couple of you guys have mentioned cracks to your cables, can you expand on this a little bit please? What do you mean by cracks? Is the Umbillical very fragile and split at the slightest touch?

videocrew · « **Reply #16 on:** 30 Jul 2008, 12:45 pm »

Quote from: PurplePanties on 30 Jul 2008, 10:10 am

Can I also ask, a couple of you guys have mentioned cracks to your cables, can you expand on this a little bit please? What do you mean by cracks? Is the Umbillical very fragile and split at the slightest touch?

It's not the cable that is cracking, it is the jack on the VDA-1 and VAC-1. The jack on my VDA is particularly bad, the cracked part bent backwards in the unit and I had to open it up to bend it back into place and hold it as I plugged the cable in. Kind of a pain, but it works now.

Amiratos · « **Reply #17 on:** 24 Oct 2008, 04:58 am »

I use the Revelation silver umbilical cable between my VDA-2 and the VAC-1 and, in my opinion, the difference against the stock cord is pretty noticeable, better definition and bass, more speed and information in all frecuencies......IMHO.

The Transport is a modiffied Oppo 981 connected to CI Audio with an Analysis Plus Coaxial cable, the power cords are a VD Nite II to the Oppo and Audience (with Oyaide and Furutech FI-50 plugs) to the DAC; the ic's to the pre are Audience AU -24 and Nordost Enchantress (fitted with Eichman RCA Bullet plugs).

The rest of the system is a Modwright SWL-9.0 SE Linestage, a pair of Nuforce Ref. 9 monoblocks, and Dynaudio Focus 220 speakers... all powered with a PS Audio Power Plant Premiere....... this setup is very transparent and sensitive to all cable changes and this justify the extra bucks for the umbilical cord.

jrebman · « **Reply #18 on:** 25 Oct 2008, 02:30 pm »

So, what's the right size allen wrench, or is it a torx?

Thanks,

Jim

Amiratos · « **Reply #19 on:** 27 Oct 2008, 01:00 am »

Allen, don't know the size, but you can find a lot of sets in the market that carry the right size !!