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Topic: Fender Steel King - Gain Potentiometer - replacement? HELP!! |
Joe Alterio
From: Irvington, Indiana
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Posted 10 May 2017 6:32 am
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Hi everyone,
I somehow busted off the pot shaft for the gain control on my Steel King. The pot says it is a 100K30A but I cannot find ANY such part on the web where it has the long D-shaped pot shaft (they all have a shorter, fully-circular pot shaft). Yet, I am able to find a 100K30C pot that looks like it has the right pot shaft. Would this work? I would have thought the "A" stood for amps, but I'm not sure what the "C" means then....help!!!
Thanks!!
Joe |
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Rick Abbott
From: Indiana, USA
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Joe Alterio
From: Irvington, Indiana
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Posted 10 May 2017 6:53 pm
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Rick - that's the one that has a fully circular shaft (not "D" shaped) and the shaft is only about 1/2 as long as what is on the Steel King ![Sad](images/smiles/icon_sad.gif) |
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John Bresler
From: Thornton, Colorado
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Posted 11 May 2017 9:22 am
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Here's a company that states they carry a complete line of fender replacement pots.
Might be a source.
I haven't had any dealings with them so can't vouch for them.
http://www.amprepairparts.com/fenderpots.htm
![Cool](images/smiles/icon_cool.gif) |
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Ken Fox
From: Nashville GA USA
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Ken Fox
From: Nashville GA USA
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Ken Fox
From: Nashville GA USA
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Posted 11 May 2017 3:46 pm
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Your pot would be an "A taper (audio taper) the "C" taper is anti=log. B taper is linear
![](http://bb.steelguitarforum.com/userpix1504/2629_potentiometer_taper_1.jpg) |
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Ken Fox
From: Nashville GA USA
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Posted 11 May 2017 3:56 pm pot
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info from the net:
If you used an audio/log taper pot for the control of the power supply we mentioned, the output voltage would increase very slowly at first, creeping up to maybe 10% of the final output at 50% of the pot rotation. It would then blast the other 90% in the last half of the rotation - very hard to control. Likewise, if we used a linear pot for volume control, the volume would come up dramatically in the first half of pot rotation, and then do very little change in the last half.
The dark horse taper is reverse audio, or more strictly "right hand logarithmic" taper. This taper traverses resistance very quickly at first, then more slowly as it is turned further. It's the inverse of the audio taper. This is used in some bias circuits and in controlling the speed of certain RC oscillators, which is where the audio tinkerer runs into it most. |
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Steven Paris
From: Los Angeles
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Posted 11 May 2017 4:23 pm
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From Rod Elliott:
"Unless you pay serious money, the standard "log" pot you buy from electronics shops is not log at all, but is comprised of two linear sections, each with a different resistance gradient. The theory is that between the two they will make a curve which is "close enough" to log (or audio) taper. As many will have found out, this is rarely the case, and a pronounced 'discontinuity' is often apparent as the control is rotated. Take a 100k linear pot (VOL), and connect a 12K (1%) resistor between the wiper and bottom end to achieve the curve shown(http://sound.whsites.net/project01.htm). It should be a straight line, but is actually still far more logarithmic than a standard 10K log pot. The other advantage of the 'fake' log pot is that linear pots usually have better tracking (and power handling) than commercially available 'log' pots." _________________ Emmons & Peavey |
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Joe Alterio
From: Irvington, Indiana
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Posted 11 May 2017 4:25 pm
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Thanks, Ken - the taper is the key, I suppose. You suggest using a "C" which is reverse log...I have also located a "B" with the D-shaped shaft which is log. Obviously, both of these are different than the "A" which is linear...and the "A" with a D-shaped shaft is not made by anyone (including Fender) anymore. Wouldn't the "B" be the better choice, since the volume wouldn't be so sensitive so soon?
Thanks in advance....
Joe |
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Tommy Detamore
From: Floresville, Texas
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Posted 11 May 2017 8:00 pm
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This is a very timely thread for me. Just today I found a Steel King in a pawn shop. It too has a broken gain pot shaft. I didn't buy it mainly because I wanted to see what might be out there to use as a replacement before I committed.
Thanks for all the info y'all. _________________ Tommy Detamore
Quilter Labs, Goodrich Sound, Source Audio, Neunaber Audio, and Stringjoy Authorized Dealer
www.cherryridgestudio.com
www.steelguitartracksonline.com |
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Ken Fox
From: Nashville GA USA
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Posted 12 May 2017 4:09 am
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The ear reponds better to the audio taper pot. The B pot would appear to come on faster. |
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Tommy Detamore
From: Floresville, Texas
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Joe Alterio
From: Irvington, Indiana
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Posted 12 May 2017 4:39 am
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Ken Fox wrote: |
The ear reponds better to the audio taper pot. The B pot would appear to come on faster. |
With the "A" (audio taper/linear) pot no longer available for this amp, it would appear the "B" (log) pot would be a better choice over the "C" (reverse log) pot, since the C would come on even faster than the "B"....am I thinking about this correctly? |
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Tommy Detamore
From: Floresville, Texas
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Posted 12 May 2017 5:06 am
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I am wondering how much it even matters Joe, since this is more of a "set and forget" application. Not like a pot in a volume pedal for example.
All three types go to 11 ![Smile](images/smiles/icon_smile.gif) _________________ Tommy Detamore
Quilter Labs, Goodrich Sound, Source Audio, Neunaber Audio, and Stringjoy Authorized Dealer
www.cherryridgestudio.com
www.steelguitartracksonline.com |
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Ken Fox
From: Nashville GA USA
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Posted 12 May 2017 6:37 am
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the "C" taper would be my choice. |
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Joe Alterio
From: Irvington, Indiana
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Posted 12 May 2017 9:38 am
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Thanks to you Ken, Steven and Tommy
I have ordered the part and shall try to get this new pot installed....now to try and get the speaker wire unhooked....it's almost like it is soldered at the connection point to the housing of the cone. ![Sad](images/smiles/icon_sad.gif) |
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