Another question for Frank (or anybody)

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Wayner

Re: Another question for Frank (or anybody)
« Reply #20 on: 13 Mar 2009, 11:37 am »
If you have to make your cables that long, I suggest www.bluejeanscable.com, the LC-1. They have a cable (made by Belden) that only has 12.2pf/foot capacitance. At 10 feet, you would be at 122pf. At 15 feet, you would have 183pf. This is the only coax cable I know of with this low of capacitance rating. I don't know if those numbers, especially for the 15 footer are bad or not. Perhaps Frank can add a nod one way or the other. I do think the 10 footer is OK as I have seen some 3 foot cables with  higher capacitance.

Mornin' Frank

Wayner

turkey

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Re: Another question for Frank (or anybody)
« Reply #21 on: 13 Mar 2009, 12:27 pm »
If you have to make your cables that long, I suggest www.bluejeanscable.com, the LC-1. They have a cable (made by Belden) that only has 12.2pf/foot capacitance. At 10 feet, you would be at 122pf. At 15 feet, you would have 183pf. This is the only coax cable I know of with this low of capacitance rating. I don't know if those numbers, especially for the 15 footer are bad or not. Perhaps Frank can add a nod one way or the other. I do think the 10 footer is OK as I have seen some 3 foot cables with  higher capacitance.

Yes, I would agree that LC-1 is the one to use.



avahifi

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Re: Another question for Frank (or anybody)
« Reply #22 on: 13 Mar 2009, 01:44 pm »
I agree, if you absolutely must use long interconnects, go with the bluejeans cables.

Frank

TomW16

Re: Another question for Frank (or anybody)
« Reply #23 on: 13 Mar 2009, 02:31 pm »
Thanks for all the feedback.

Is it possible to get away with using cables from a preamp to a power amp that are between 10 to 15 ft long without any deterioration in signal quality?  I am thinking of purchasing an Insight EC preamp and a Insight Power amp.  Would using balanced cables with an adapter to convert to RCA on each end create problems?  Frank???????????  Anybody???????

To make effective use of a balanced cable, the electronics need to be balanced as well.  Balanced cables with an adaptor simply do not use one of the leads in the balanced cable just as a single ended cable uses and now you have an adapter in the mix.  I would recommend sticking with RCA cables if that is what you have on the electronics.

Cheers,
Tom

turkey

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Re: Another question for Frank (or anybody)
« Reply #24 on: 13 Mar 2009, 03:15 pm »
Thanks for all the feedback.

Is it possible to get away with using cables from a preamp to a power amp that are between 10 to 15 ft long without any deterioration in signal quality?  I am thinking of purchasing an Insight EC preamp and a Insight Power amp.  Would using balanced cables with an adapter to convert to RCA on each end create problems?  Frank???????????  Anybody???????

To make effective use of a balanced cable, the electronics need to be balanced as well.  Balanced cables with an adaptor simply do not use one of the leads in the balanced cable just as a single ended cable uses and now you have an adapter in the mix.  I would recommend sticking with RCA cables if that is what you have on the electronics.

Cheers,
Tom

Correct. It isn't the cable that is balanced, it is the electronics on either end of it.

Using a shielded twisted-pair cable for an unbalanced connection is going to actually reduce performance over a properly designed coax cable.



thunderbrick

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Re: Another question for Frank (or anybody)
« Reply #25 on: 13 Mar 2009, 05:27 pm »
To take this question in a related direction, suppose I put my DVD player under my TV and run interconnects back to a preamp 15 ft away. Will I have the same issues as has been described using long ICs between amp and preamp, or is a CPD or DVD player less fussy?

I wonder if Audioquest publishes capacitance data?  I have a very long set of AQ cables that I might cut down.

And lastly, how do I measure capacitance of cables?

Thanks,

Bob

Wayner

Re: Another question for Frank (or anybody)
« Reply #26 on: 13 Mar 2009, 06:17 pm »
You need a DMM that can read pico-farads. That would be a rather spendy device. Best to look for cable specifications.

Wayner

turkey

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Re: Another question for Frank (or anybody)
« Reply #27 on: 13 Mar 2009, 06:49 pm »
You need a DMM that can read pico-farads. That would be a rather spendy device. Best to look for cable specifications.

Wayner

I bet that the only concrete, verifiable specs that AQ publishes are the length of the wire.

Wayner

Re: Another question for Frank (or anybody)
« Reply #28 on: 13 Mar 2009, 07:57 pm »
I'll bet your right. I tried to find some specs on Monster cable...to no avail.

We have a pico meter at work but it's about $5k worth. I believe pico = trillionths of a farad, or 10-12th, or 1 farad = 1,000,000,000,000 picofarads. That is a tiny amount. Funny how small amounts of capacitance can raise hell with a micro-volt signal.

Wayner  :D

thunderbrick

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Re: Another question for Frank (or anybody)
« Reply #29 on: 13 Mar 2009, 08:21 pm »
It turns out a buddy has a capacitance meter and knows how to drive it.  I'll work with him in the next few days.
The ICs, by the way, are Audioquest Topaz 25' long.  Anybody had any experience with 'em?

Thanks to all who responded!   :thumb: