Pundit
Post by Gryffles on Feb 17, 2017 21:48:34 GMT 12
Gents,
Just looking at getting the bits and pieces together to build a set of interconnects to go between TT and Phono stage. Will be no longer than 75cm
I'll use Discovery wire which matches the tonearm and will use a braid shield. I was thinking of splitting the 4 twisted wires and using one run for each + - with the shield used as a shield only.
I have a couple of questions though:
Should the braid shield be grounded to the - RCA pin at one end only?
Is it good practice to create some space between the shield and the + - wires ie use some cotton tubing, for example, between shield and wire?
Should I use two runs of wire for each + - ?
There is a lot of info around and a lot of it conflicting. Any other tips or ways to improve would be appreciated too.
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Post by Owen Y on Feb 17, 2017 22:16:34 GMT 12
A quick note.... Single conductor for ea of +/- times 2 ch's = 4 conductors, yes I concur. Gentle twist ea +/- pr. Metal screens IMO affect the fields around the signal wires & I do not use a screen, just twist the signal prs. You could always add a screen later. Should be hum-free. If incorporating a screen, ground preamp end only to -ve contact in the RCA plug - that way it gnds to preamp Gnd/Earth. And yes, IMO if using a screen, separation from signal conductors can only be beneficial. And natural cotton should b a nicer choice than synthetic materials. Cheers
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Post by Owen Y on Feb 18, 2017 9:14:51 GMT 12
Hi Gryffles - others will have useful comments, but just to elaborate.... Unless you have a tight, busy environment, with say lots of AC power cabling, transformers, AC mtrs, etc nearby, I would try without screen/shield. However, incorporate the screen if you are worried. (Your main enemy is hum, ie EM radiated AC fields & twisting is the standard technique to 'cancel' any pick-up. A shield may help with any RF airborne noise, if you have such a 'noisy ' environment.) Discovery (33ga tonearm wire?) is long-standing product, so should be good. I find no problem with longish (~1m from cartridge) 33ga Cardas runs without need to double up. I twist +/- & depending on wire, it may need occasional tape or heatshrink to hold it. Then twist L/R ch's if you wish. RCA plugs - I like Eichmann Bullet plugs, regular copper ones, a little costly but good for low signal phono esp . What's your choice?
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Post by michaelw on Feb 18, 2017 10:21:47 GMT 12
dedicated phono cables are usually screened to block out noise.
don't think i've ever seen an unscreened phono cable ?
even xlo, long time proponent of unscreened interconnects use an optional shield on their phono cables.
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Pundit
Post by Gryffles on Feb 18, 2017 11:40:22 GMT 12
Hi @owen Young,
Thanks for the reply. One conductor per + / - seemed a good idea to me too.
Yes I'll be using 33ga Discovery wire which isn't Litz like most other phono wire. I will try with no shield as my other DIY IC's are un-shielded and I didn't have a problem although they weren't for phono duty.
My RCA choice is the MS Audio Star Line copper. A bit cheaper than the ETI/KLEI ($50 inc freight for 4) versions but are basically identical in design.I have some Cardas solder that I can use.
Thanks
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Pundit
Post by Gryffles on Feb 18, 2017 11:42:04 GMT 12
dedicated phono cables are usually screened to block out noise. don't think i've ever seen an unscreened phono cable ? even xlo, long time proponent of unscreened interconnects use an optional shield on their phono cables. Yes and I think they have to build that way for worst case scenario. I'll try without and see how I get on.
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Post by Owen Y on Feb 20, 2017 10:23:53 GMT 12
Those MS Audio Star RCAs look worth trying, less expensive copies of Eichmann Bullets it seems. If you have a choice, go for Gold plated, rather than Rhodium. Cheers.
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Pundit
Post by Gryffles on Feb 20, 2017 16:38:22 GMT 12
Those MS Audio Star RCAs look worth trying, less expensive copies of Eichmann Bullets it seems. If you have a choice, go for Gold plated, rather than Rhodium. Cheers. Yep, they look the same internally. Gold was my choice. Never heard rhodium but some say it sounds cold.
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Member
Post by georgios on Feb 27, 2017 20:00:35 GMT 12
Well, have to say everyone has his theory but I usually solder shield at both end.
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Post by Owen Y on Feb 27, 2017 21:43:12 GMT 12
Well, have to say everyone has his theory but I usually solder shield at both end. Not my theory, just my understanding (with unbalanced ICs w separate shield), best tech practice is to connect shield to lowest impedance end (usually source end) for lowest induced noise. Connecting both ends of course creates a *possible* hum loop. With phono ICs, only the preamp end is Grounded, so shield connection should be to this end. Cheers.
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Pundit
Post by Gryffles on Mar 13, 2017 16:10:40 GMT 12
The Star RCA plugs have arrived and look the business. As suggested they are very good copies of KLEI / ETI Hollow +ve pin and single contact -ve both with small solder lugs. These are the silver version  
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Post by Owen Y on Mar 13, 2017 16:59:28 GMT 12
Good - avoid Rhodium I reckon.
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Pundit
Post by neilsan on Mar 13, 2017 18:25:30 GMT 12
"My RCA choice is the MS Audio Star Line copper."
Hi Gryffles. Where do you get your plugs from? Thanks.
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Pundit
Post by Gryffles on Mar 13, 2017 20:12:25 GMT 12
Hi neilsanI found the cheapest Ebay seller is: tortoise6688
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