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  #1  
Old 16th August 2012, 12:19 AM
davew davew is offline
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Location: Deal
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Default Shunt pot values

Hi,

I have a WD Phono 3 driving a K5881 MK 2 power amp.
When finances allow I'd like to get a PRE3 but for the time being I'm just using a simple 47k volume pot on the power amp input.
I'm planning to add the shunt pot mod - Is there any particular pot/resistor combination that would suit the output/input impedances of these?
Pot position for normal listening is around one quarter so some attenuation is fine,

Many thanks
Dave
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  #2  
Old 16th August 2012, 09:05 AM
Richard Richard is offline
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Default Re: Shunt pot values

Hi Dave,

Yes, good amp to use the shunt pot on as it's so sensitive.

I'd try 47K series R with your 47K pot first. This will give a similar normal position but expands the higher levels with a -6dB attenuation at max.

If you want to expand the pot range lower down try 100K series R which will move the normal point further round and give -9.5dB at max.

The Maplins 0.6W metalfilms work well with the Alps.

http://www.world-designs.co.uk/forum...ead.php?t=5795
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  #3  
Old 17th August 2012, 03:19 PM
davew davew is offline
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Default Re: Shunt pot values

OK Thanks for the info
I'll give it a try with the 47k resistor
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  #4  
Old 17th August 2012, 08:47 PM
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Ali Tait Ali Tait is offline
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Default Re: Shunt pot values

Audio Note tantalums are the best sounding resistors I've tried for this. Charcrofts may be even better but are not cheap.
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  #5  
Old 27th August 2012, 09:35 PM
FreddieT FreddieT is offline
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Default Re: Shunt pot values

I used a 47k metal film with a 50k ALPS Blue in shunt to great effect between the Phono3 and my K5881 Mk II. More laterly I used a 100k series resistor at the input of the K5881 as I moved to my home brew CF pre amp (6SN7 based, photos when I've tidied it up) with an AN pot. This was primarily to help the comparisons between the Naim NAP250, the WD KT88 XL (now installed on a permanent basis) and the K5881.

Should anyone be interested I found that the 5881 edged it on detail but the KT88 had the drive and bass that I was missing moving from Naim, but most of the detail of the other valve amp. I also had the enjoyment of building another WD kit!

F.
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