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Topic: Capacitor value for a 1937 Gibson? |
Jim Williams
From:
Meridian, Mississippi, USA - Home of Peavey!
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Posted 29 Jun 2017 10:45 am |
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I have my Dad's old 1937 Gibson EH-150. It is probably the best lap steel I have, but I seldom play it because it just seems to have too much high end for me. Even at the most bass setting of the Tone pot, it is still very bright and there is no sharp roll off.
My dad was known to do some experimenting, and I remember him liking a very high sound...so I'm thinking he may have changed the value of the capacitor, since he was also an electronics technician.
Do any of you know what the value of the original capacitor in this vintage of guitar was? I believe the tone pot is a 500k.
Thanks!
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GFI SM10 3/4, 1937 Gibson EH-150, 2 - Rondo SX Lap Steels and a Guyatone 6 String C6. Peavey 400 and a Roland 40 Amps. Behringer Reverb Pedal. |
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G Strout
From:
Carabelle, Florida
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Posted 29 Jun 2017 11:43 am
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Jim,
This is likely a bad capacitor. Lot of the old guitars had wax / paper capacitors and they dry out and lose capacitance over time. There may be also a series resistor in there that would have an effect on the tone as well if it has gone bad, but that is a lot less likely than the capacitor. The control itself normally will not cause a problem other than excessive noise if it gets dirty. Now if Dad did some experimenting it would be hard to say what values you have in there. Don't quote me on this but I believe the EH150 had 500k pots and a .05mfd cap.
The tone pot and capacitor comprise a low-pass filter, so, when you lower the pot,the treble bleeds to ground and your tone gets darker.
The two most often found values in modern production guitars are 0.022µf and 0.047µf. The higher the value of the cap, the more high frequencies it rolls off, therefore it’s common to find a 0.047µf cap on single coils and a 0.022µf cap used with humbuckers. You can also have fun experimenting with cap values until you find the sound that you like. I would add them to the circuit using some alligator clips until I found the tonal range that I liked. Then I would solder it in.
Hope this helps.
gary
Last edited by G Strout on 29 Jun 2017 11:47 am; edited 1 time in total |
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Jim Williams
From:
Meridian, Mississippi, USA - Home of Peavey!
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Posted 29 Jun 2017 11:46 am
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That does help, I just need to pull it down and see what is in there. I had the pickup professionally rewound to it's original specs a couple of years ago because it had opened up, but is still just has a very thin sound. The old guitar means a lot to me, although the finish is absolutely gone. I would like to have it restored someday.
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GFI SM10 3/4, 1937 Gibson EH-150, 2 - Rondo SX Lap Steels and a Guyatone 6 String C6. Peavey 400 and a Roland 40 Amps. Behringer Reverb Pedal. |
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Tony Oresteen
From:
Georgia, USA
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John Dahms
From:
Perkasie, Pennsylvania, USA
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Posted 30 Jun 2017 7:06 am
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In answer to your original queation EH-150 with the "charlie Christian" style pickup (like yours came with an .02 mfd. @ 400 or 600v cap. (any voltage will be fine). Yours is probably bad if there is no tone change.
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Time flies like an eagle
Fruit flies like a banana. |
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Kelvin Monaghan
From:
Victoria, Australia
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Posted 1 Jul 2017 3:44 pm
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There is also a resistor in series with the cap,10k I think,on mine the tone pot is quite subtle and the CC pickup is very bright.Possibly remove the resistor that should give more response to the tone pot
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