White noise from C4S?

AudioFan · 3464

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Offline AudioFan

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on: October 14, 2010, 09:04:20 AM
Greeting to all ... I just joined the forum.

I wish to ask if anyone has encountered white noise from a C4S load? 

I am using C4S loads in my phono, where they perform really well (sonically I mean).  However, I appear to have some issues with white noise.  Not hugely loud, but irritating nevertheless. I suspect the LED's in the C4S may be the cause?

Anyone had an issue of this kind?
What to do to solve the problem?

Any thoughts on this matter would be greatly appreciated by me

Regards
AudioFan




Offline Paul Joppa

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Reply #1 on: October 14, 2010, 09:48:49 AM
We have not seen that problem in any of the phono or tape head preamps. The LEDs are chosen specifically for their particularly low noise and low dynamic resistance.

If you can share more information on the circuit and circumstances, we may be able to help more - this forum has a lot of experienced eXperimenters!

Paul Joppa


Offline Grainger49

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Reply #2 on: October 14, 2010, 09:50:03 AM
I have the Seduction +C4S.  There is no noise produced by that combination.  Is that what you are using?



Offline grufti

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Reply #3 on: October 14, 2010, 09:19:13 PM
Very odd and very unlikely.

I assume that you are comparing before and after C4S. Those LED's will not contribute to audible noise in the Seduction.



Offline AudioFan

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Reply #4 on: October 15, 2010, 01:19:42 PM
Thanks for your input ... much appreciated.

The phono in question is my own design ... currently with 6n1p/riaa/12BH7/6H30

As noted, I have some issues with white noise, on one channel ... I thought it 'might' be C4S related, but I can see form the kind replies to my original post that this is unlikely.

For all I know the noise issue could be due to a dry joint, or dodgy tube socket ... I am in process of a chassis rebuild anyways, so hope to solve this aspect in the process of the rebuild.

Thanks once again for re-assurance regarding C4S ... I really like the sonic aspect from these devices, by the the way.

Regards
AudioFan



Offline JC

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Reply #5 on: October 15, 2010, 01:51:31 PM
I, too, have never had noise that I narrowed down to a C4S, and I have used a few of them here and there.

Having said that, I would speculate that if a C4S was the culprit, I would be more inclined to think that one of the transistors was acting out.  A shot of freeze spray directed at each transistor may help in deciding if one has decided to go noisy.

Jim C.


Offline Paul Joppa

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Reply #6 on: October 15, 2010, 02:39:23 PM
Is the 6N1P old? Have you swapped it? Great tube (my buddy richardl has a phono using them) but some have been known to fade sooner than you'd like. Just a thought.

Paul Joppa