Seduction hum (how much is normal?)

denti alligator · 69848

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Offline Doc B.

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Reply #120 on: October 26, 2012, 07:44:59 AM
Actually I meant another electronic component in the circuit. For example a wire or a tube in the Seduction itself could be picking up transformer hum of the PT-1. This is measurable in a Seduction in the right channel due to the proximity of the circuit components to the power transformer, though it is seldom noticed by ear unless the cartridge is a very low output type. But variations in sensitivity to hum pickup can vary quite a bit from tube to tube. That's why it is difficult to quote a "normal" figure. Since this problem only seems to be present when you listen with headphones and not with speakers it seems like it may be right on the threshold of what could be considered normal. And that is why I feel that I would have to listen and measure it myself to give a more confident answer about whether it is typical or atypical performance.

Dan "Doc B." Schmalle
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Bottlehead Corp.


Offline denti alligator

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Reply #121 on: November 15, 2012, 12:29:43 PM
HOLY MOLE!!  O  M  G !!   :o

The hum is gone!

Gone, I say.

Yep, the amp is quiet. I can't tell you how good this feels. I sent the amp to Bottleheadquarters to get looked at and it got damaged in the mail. So it's hard to say what the source of the hum was (I'll let PB chime in with details), but whatever they did it's better now.

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Paul Birkeland

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Reply #122 on: November 15, 2012, 12:51:44 PM
I wish I knew what specifically made the difference, but all that shipping damage didn't leave me a particularly accurate picture of what was going on before. 

I'm sure shortening the leads a bit helped, but it's anybody's guess I suppose!

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline denti alligator

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Reply #123 on: November 15, 2012, 04:48:00 PM
For me what's most important is that what I was hearing was NOT normal. I was concerned that I was just overly sensitive. Nope, it was not normal. [phew]

Now I can get back to nitpicking about other minor imperfections in my phono set up  ;)

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline Laudanum

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Reply #124 on: November 26, 2012, 03:48:31 AM
Just noticed this.  Congrats Sam.  Very happy to hear that you finally got it all sorted out.  Leave it to the Bottlehead gang, if they can design it, they can surely fix it  ;)

Desmond G.


Offline Jim R.

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Reply #125 on: December 04, 2012, 06:35:43 AM
Sam,

How close to the s.e.x. can you place the seduction without getting any interference or noise from the power amp?

Thanks,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline denti alligator

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Reply #126 on: December 04, 2012, 11:26:16 AM
Lemme get back to you on that. Right now it's about 1 1/2 feet away and no problems.

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable