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  #1  
Old 11th February 2007, 12:27 PM
buddam buddam is offline
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Default Phono II i/p resistor to earth

I've varied the resistor to earth on the Phono II in a range from 2.4K to 4.2K. Using a Dynavector needing 30R (which through the step-up txs means 3K).

I hear virtually no difference. Indeed, mounting all the pairs of Rs on a separate baord, connected via crocodile clips, if I remove the croc clips so that there is no connection to earth, nothing changes.

Is this normal or must I have made a mistake somewhere?

Thanks

Adrian
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  #2  
Old 11th February 2007, 01:08 PM
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NickG NickG is offline
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Default Re: Phono II i/p resistor to earth

What stepups are you using?

It may just be the case the dynavector isn't very sensitive to load.
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Old 11th February 2007, 03:47 PM
buddam buddam is offline
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Default Re: Phono II i/p resistor to earth

Standard WAD D8749. Know anything about them?

I also wondered about sensitivity. Perhaps you recall how at the first Withamfest my phono II sounded awful with Gerry's SP10 + 103, which IIRC needs a 4K load. Part of the reason for making this off-board load resistor 'switch' is to test a 103 Gerry's lent me.

Actually, just read an old thread where you pointed out difference between source resistance and load, which for a 103 is 20-25K.

Any opinions anyone on why no difference if I disconnect the link to earth of R13/14?

Cheers

Adrian

Last edited by buddam; 11th February 2007 at 04:21 PM.
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  #4  
Old 11th February 2007, 04:24 PM
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Default Re: Phono II i/p resistor to earth

Assuming the step-ups ate 1:10, then a 103 will need something more like 10k-15k.

You have varied the dynavector load from 24R to 42R, I can believe that a low impedance output cart wouldn't produce that much change over that range.
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Old 11th February 2007, 04:56 PM
buddam buddam is offline
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Default Re: Phono II i/p resistor to earth

Yes 1:10. The 103 specs leaflet recommends 100R (x 100 = 10K), but I see others use up to 25K. Maplins tomorrow for some higher value resistors
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