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 Post subject: Re: potentiometer differences
 Post Posted: Mon Dec 15, 2008 7:33 am 
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Joined: Thu Nov 20, 2008 7:20 am
Posts: 430
Location: Spring Valley Ca.
Thank's again Bros. Armed with a lot of great info, I am becoming more capable of making informed decisions. Thank's Mark


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 Post subject: Re: potentiometer differences
 Post Posted: Mon Dec 15, 2008 2:22 pm 
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Joined: Wed Nov 16, 2005 2:00 pm
Posts: 2962
Location: Scotland
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The bridging resistor to bring down the effective value of the pot bridges across the center wiper and the hot lug in, NOT the ground.
But that won't bring down the effective value of the pot - not when it's full up, anyway. The resistor is then bypassed by the pot rotor being in contact with the top lug. It will certainly reduce the apparent value as the pot is turned down, but on a sliding scale and only becoming fully effective at zero.

To reduce the effective value of the pot as a load on the pickup, the resistor DOES need to be in parallel with the whole track, from the top lug to ground. This is what provides the load on the pickup.

Volume pots don't work just as a variable resistor, they work as a potential divider, and it's the ratio of resistances between ground, input and output that controls the overall volume - if it didn't work like this, the volume would never go to zero.

If you don't believe me, try lifting the ground lug on a volume pot and see what happens!


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 Post subject: Re: potentiometer differences
 Post Posted: Tue Dec 16, 2008 3:24 am 
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Joined: Sun Oct 08, 2006 6:07 am
Posts: 3831
From the perspective of a load divider, like in the phase inverter to power tube link in a tube amp, yes, I agree with you. And choosing that value is significant when determining what load characteristic you want on the pickups.

But wiring it across the wiper and hot lug also does in this configuration what I want it to do, and that is to change the ramp somewhat, without changing the loading characteristic, since the primary function of the volume control is just that, single side, or unbalanced volume. With the control full on, you're getting straight signal through save what is loaded to ground regardless, and by choosing the primary value of the pot, that determines the loading characteristics. Then the bridging resistor serves through the intermediate stages of the sweep or wipe to flatten the log or audio curve somewhat, as the resistor passes a tad bit of the signal on through from hot lead to wiper then out to jack.


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 Post subject: Re: potentiometer differences
 Post Posted: Wed Sep 25, 2019 12:33 pm 
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Joined: Wed Aug 14, 2019 1:18 pm
Posts: 11
Location: Litchfield N.H.
I bought a re=issue V63 wire harness back in the '90's, I,m confused because the prt# on the pots are #07341. This isnt the same # as the 330K prt#.The only other number on the pots is 9815. Sometimes I live with the wonders of short term memory loss and ordered a CTS 500k solid shaft last night for my 4001. I must have seen a relationship between the Ric #07341 and a 500k pot some where, otherwise I wouldn't have ordered it .can any one fill me in ?.sorry I didnt want to bust in on ricmic's post but it has been 10 years after all.


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