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  #21  
Old 22nd February 2013, 02:17 PM
Richard Richard is offline
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Default Re: Pre3 problems.

Hi Dik, yes response looks fine still doesn't it

The extra movement to get to your old vol level will just be the pot law and not a difference in drive so no probs there.

You could change the low end of the shunt pot arrangement with different series resistor value (higher) or a different Alps (lower) which is why I went for a 20K with 47K series R's to get a bit of movement at the bottom without changing the input impedance too far away from standard 47K.

Which series R's are you using with the 47K Alps btw? (Edit, ah sorry just looked back and you have 47K pot and 47K R's. Just change to 100K R's or a 20K pot if you did want more bottom end control.)

Be interesting to hear how you find the new pot on longer listening.
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  #22  
Old 22nd February 2013, 02:33 PM
Dik Dolan Dik Dolan is offline
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Default Re: Pre3 problems.

Hi Richard,
My shunt resistors were 47k. It was just about usable from a volume point of view, it wasn't "that" twitchy once it got turned up from the almost off position. The thing that got to me most was the channel balance at low settings. It wasnt even constant. A small change in volume altered the left/right balance too. At very low volume, the right channel became audible while the left was still silent. Got a bit annoying=)

I guess I could have tried upping the resistor value, but then I saw the "new old stock" p&g pot on ebay and it was too good to pass up=) I've not used one before, but their reputation for quality seems to be justified.

My other option was trying the dact pot I have (somewhere), that has perfect channel balance, but I just cant get on with stepped volumes. I'm just a fussy git I suppose, with slightly weird requirements. I only listen at very low to moderate volumes, so channel balance especialy at the bottom end of the pots gets put under more scrutiny that usual. So far the volume range and balance of the p&g is perfect. I doubt I'll try shunting it..but too soon to tell=)
I'm not going to rush into any conclusions, but so far so good.
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  #23  
Old 9th April 2014, 09:59 AM
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pre65 pre65 is offline
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Default Re: Pre3 problems.

My Pre3 has had an annoying problem for a while, intermittent noise on one channel.

I eventually found it seemed to be the valve base. Bending the holding leaves with a tiny screwdriver effected a temporary cure, but now it looks like I'm going to have to replace the base complete.

Deep joy.
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  #24  
Old 9th April 2014, 11:56 AM
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Default Re: Pre3 problems.

I'm getting two gold plated PCB bases from Matthew, might as well do both whilst I'm at it.

In for a penny.......
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  #25  
Old 11th April 2014, 10:59 AM
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Default Re: Pre3 problems.

Excellent service from Matthew, my valve bases were received the next day.

Thanks Matthew.
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  #26  
Old 1st January 2019, 03:25 PM
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Default Re: Pre3 problems.

Can anyone remind me what valves the Pre3 uses please ?

The old ones look like they may be ECC82.
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  #27  
Old 1st January 2019, 05:24 PM
bob orbell bob orbell is offline
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Default Re: Pre3 problems.

You are correct Philip. BOB
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  #28  
Old 3rd January 2019, 12:37 AM
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Default Re: Pre3 problems.

Thanks Bob.
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