Using Bottlenect Interconnects

rockpassion · 3273

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Offline rockpassion

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on: January 12, 2015, 04:38:29 PM
Hello all,

I built a Cinemag 3440a SUT years ago and think it is great.  I used to use a Seduction Phone Preamp but have upgraded to the EROS.  I had a hum with the Seduction but it was so low that it was not really to noticeable.  I recently noticed with the EROS that the hum is much louder and noticeable.  I believe I have figured out the SUT is causing the hum.  The reason for this conclusion is as I move the SUT closer to the EROS the hum gets louder.  I read over on Audio Asylum that getting shielded cables might take care of this problem. 

Are the Bottlenect Interconnects shielded and would this help?  Or, should I also shield the box the SUT is in.  The box is plastic. 

Thanks

Richard

Richard Vince

VPI MkIV, Woody Tonearm w/Shelter 501 MkII Cart. w/Soundsmith rebuild, Cinemag CMQEE-3440A SUT, Eros Phono Preamp, Beepre Preamp , QuickSilver V4 Amps, DIY 89259 Speaker Cables  & interconnects, VH Audio Power Cables, OPPO 205 Player, DIY 3 way speakers


Offline Paul Birkeland

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Reply #1 on: January 12, 2015, 04:50:10 PM
Are you able to rotate the individual SUT's and to rotate the entire assembly?  Often such hum can be nulled by both distance and orientation.  I am also guessing that you provided a ground connection for the shields of the SUT cans? (On a separate post, not the RCA jacks)

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline rockpassion

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Reply #2 on: January 12, 2015, 05:11:22 PM
Paul,

You are right the hum decreases as I rotate the SUT.  Right now it is in a position that lessens the hum to its lowest level.  The SUT is grounded to its own post which is grounded to the post on the EROS.  I have played with this a couple of different ways and does not seem to have an affect on the hum. 

If I was to add copper foil to the SUT box would that help shield the Transformers from the other transformers?

Richard

Richard Vince

VPI MkIV, Woody Tonearm w/Shelter 501 MkII Cart. w/Soundsmith rebuild, Cinemag CMQEE-3440A SUT, Eros Phono Preamp, Beepre Preamp , QuickSilver V4 Amps, DIY 89259 Speaker Cables  & interconnects, VH Audio Power Cables, OPPO 205 Player, DIY 3 way speakers


Offline Paul Birkeland

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Reply #3 on: January 12, 2015, 05:21:28 PM

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #4 on: January 12, 2015, 05:48:37 PM
Distance and orientation are probably going to be the most effective things you can change to reduce hum pickup. I've got triple shielded transformers that I spent many hours on and there seems to be a limit to how effective you (or rather, I) can make a magnetic shield. I used molyperm tape, copper tape, a mumetal can and aluminum. Also tried a steel can over the whole thing, with no improvement. After trying many different configurations mine got only slightly more quiet than Altec 4722s. They all pick up a little hum.

The real pisser is that the active step up we built had even more noise.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline rockpassion

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Reply #5 on: January 12, 2015, 07:18:04 PM
Thanks guys, I have some pretty long interconnects so I will move them away even further and continue the orientation to see how much hum can be decreased. 

Richard

Richard Vince

VPI MkIV, Woody Tonearm w/Shelter 501 MkII Cart. w/Soundsmith rebuild, Cinemag CMQEE-3440A SUT, Eros Phono Preamp, Beepre Preamp , QuickSilver V4 Amps, DIY 89259 Speaker Cables  & interconnects, VH Audio Power Cables, OPPO 205 Player, DIY 3 way speakers