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Topic: Tone pot problem |
Andrew Yanchick
From:
Pennsylvania, USA
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Posted 16 Oct 2010 3:41 pm |
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Hi everyone,I am newbe and I have a problem that I hope someone here can remedy.I purchased a tripleneck Fender lap steel from ebay and being a new player was told by my (teacher) that the tone pot was not working.After trying several pots I am still unable to get it to work.It has been to music stores in the area and no one can offer an opinion.I have even changed pots from another lap that works and it does not work in this one.When hooked to my old Dearmond volume and tone pedal it is ok but wont change tone with the goodrich pedal.Do I have to take the pot from the pedal and replace it with that?I really don't want to do that.HELP  |
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C Dixon
From:
Duluth, GA USA
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Posted 16 Oct 2010 4:00 pm
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I have read your post several times. And if I am understanding what is happening clearly, then I suspect you have an impedance miss match between the vol pedal and the PU's in the guitar.
Try this:
Plug your guitar directly into your amp bypassing anything else. Observe the following:
1. The tone control works
2. The tone control does not work.
If it works, your guitar is ok. If it does not, then there is a problem in the guitar; possibly the tone capacitor or an open circuit to same.
Now do this:
Connect your vol pedal back up. IE: Guitar>vol-pedal>amp. Make sure nothing else is connected.
If the guitar's tone control does not work, then does the volume change when you engage the pedal. If it does, you have a missmatch between the guitar and the vol pedal OR pedal to amp.
Several posibilities here:
1. Someone has wired the pot in the pedal backwards.
2. There is active circuitry in the pedal that is either defective OR is causing a missmatch.
In either case, you will need a new one, because it would probably be cheaper to buy a new one, than to pay some garage "jerky" (so-called modern day electronic repairman) to make matters even worse, mostly in your pocketbook! 
c.
_________________
A broken heart + † = a new heart. |
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Andrew Yanchick
From:
Pennsylvania, USA
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Posted 17 Oct 2010 8:56 am Tone pot problem
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| hi all |
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Andrew Yanchick
From:
Pennsylvania, USA
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Posted 17 Oct 2010 9:09 am Tone pot problem
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| I guess I mis stated my problem.When I plug the guitar into the amp without going thru the volume pedal I get no response.This volume pedal has it's own tone pot so yes it works when it is in the line.But the problem is that I get no tone control unless I play with the pedal.Now let's forget about the pedal for now.I plug the guitar into the amp,no tone control.I install a new tone pot,no tone control.I replace tone pot with one taken from another lap steel,no tone control.I take the guitar to the repair shop and we(guitar repairman and me)try different capacitors,no tone control.Every thing seems to point to wiring problems.Can the three neck selector switch have anything to do with this problem?I don't see how but I'll try anything.Still needing help.Thank you C Dixon for your input.Any other suggestions? |
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C Dixon
From:
Duluth, GA USA
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Posted 17 Oct 2010 10:04 am
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I am a bit confused, so let's try this.
A tone pot in MOST guitars, works as follows:
A wire is connected from one of the end lugs of the tone pot to the "HOT" side of the PU. Note it may not go directly there, but electrically it has to end there. Keep this in mind.
Then a capacitor typically a .02-.05 Microfarads, is connected to the center terminal of the pot.
And the other end of the capacitor is connected to the ground side of the PU. Again, it may not go directedly, but electrically, it MUST end there.
Note: if there is a tone control "disable switch", BYPASS it with a wire.
That is ALL there is to it.
You do not even need to touch the underside, you can do this on a table with wires temporarily soldered to a pot and a capacitor as above; all in series between your jack, and your cable going to your amp.
When you get this working....
Then check this out on your guitar. You should quickly find the cause, IF I am understanding correctly what you are saying.
But at my age, anything's possible. 
Good luck dear friend, and may Jesus lead you to the root cause of your dilemma. I Will say a prayer for this to happen, as soon as I hit send. Promise
c.
_________________
A broken heart + † = a new heart. |
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John Billings
From:
Ohio, USA
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C Dixon
From:
Duluth, GA USA
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Posted 17 Oct 2010 12:44 pm
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Yes it could be that, but ONLY if they used a value VERY much lower than 1 Meg. This due to what Andrew said, ".......It did not work at all". So even if they went down to a value of 100K (a 90% drop), there would be still SOME tonal change.
Also, I am very glad you posted that PDF drawing. Here is why: I thought about it after I sent the last post. The cap and the pot are always in series, so it does NOT matter which one is first.
So, either the cap or the pot ends up going to ground, but not both of course. And it does not matter which one connects to the PU.*
Andrew keep this in mind, and I apologize for that overlook.
c.
* For inquisitive minds: All a cap does when used in a tone circuit is to attenuate (reduce on a logrithmic scale rather than a linear scale) ever more and more highs. And it does this simply by, believe it or not, shorting them to ground.
All the pot does is to move the "grounding" further away or closer to the signal flow from the pickup.
In other words, IF you were to take that cap and while someone was playing a song, put it across the jack, (hot and ground), you would hear an instantaneous change in tone from loss of highs and mostly bass, or the highs would return and blend with the bass when you removed the cap.
You could install a momentary push button switch to do this, and get quite an affect, as you quickly pushed the button on and off. 
Speedy West was known for homemade gimmicks like this.
If none of the above makes sense, don' sweat it bretheren, for ONLY nuts like me ever cared a tinkers about it.
If it works Pet it, if'n it don't, Sweat it! But ONLY if it dont 
_________________
A broken heart + † = a new heart. |
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John Billings
From:
Ohio, USA
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Posted 17 Oct 2010 1:27 pm
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Carl,
I was thinking that it might have been a 250 K pot. You're certainly correct that it would effect the tone, but I was thinkin' that it would be only slightly, and not the dramatic shift from trebly to bassy that would be the norm. Sort of the opposite of the Gatton mod in one of my Telecasters. That's a 1 meg pot, making sort of a "Wah" sound very quickly, by only needing to turn the pot 1/4 turn to go from full bass to full treble.
JB |
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C Dixon
From:
Duluth, GA USA
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Posted 17 Oct 2010 5:04 pm
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You are correct John,
c.
_________________
A broken heart + † = a new heart. |
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Mickey Adams
From:
Bandera Texas
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Posted 19 Oct 2010 5:07 pm
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I say just take the tone control out of the equation...wire the pickups directly to the switch..Youve got a WHOLE plethora of tone shaping on your amp and this thing is choking your pickups...Ditch it!
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Allan Munro
From:
Pennsylvania, USA and Scotland
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Posted 19 Oct 2010 8:47 pm
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| Mickey Adams wrote: |
| I say just take the tone control out of the equation...wire the pickups directly to the switch..Youve got a WHOLE plethora of tone shaping on your amp and this thing is choking your pickups...Ditch it! |
Yep, passive tone controls are the spawn of the devil. See my sig line down below there? One guess what 'both modded' refers to...
_________________
Only nuts eat squirrels.
Television is the REAL opiate of the masses! |
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Brint Hannay
From:
Maryland, USA
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Posted 20 Oct 2010 8:07 pm
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I do not agree that a tone control on the instrument should be "ditched" or is the "spawn of the devil". Varying the amount of treble in the sound without having to turn to the amplifier's control panel is a worthwhile luxury, especially for a player who is seated at the instrument with his legs underneath it (even more so if the player is using pedals and knee levers). So many players use combo amps, where the control panel is in the same cabinet as the speaker(s), and the speaker cabinet should never (if you can help it) be so close to the player that he can easily reach it without changing body position--you can't properly hear what you effectively sound like with the speaker(s) so close to you.
That said, a tone control is such a dirt-simple device that I can't imagine a "guitar repairman" being unable to get it working. You need to find someone who has a clue about basic electronics. |
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C Dixon
From:
Duluth, GA USA
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Posted 20 Oct 2010 10:46 pm
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| Brint Hannay wrote: |
I do not agree that a tone control on the instrument should be "ditched" or is the "spawn of the devil". Varying the amount of treble in the sound without having to turn to the amplifier's control panel is a worthwhile luxury, especially for a player who is seated at the instrument with his legs underneath it (even more so if the player is using pedals and knee levers). So many players use combo amps, where the control panel is in the same cabinet as the speaker(s), and the speaker cabinet should never (if you can help it) be so close to the player that he can easily reach it without changing body position--you can't properly hear what you effectively sound like with the speaker(s) so close to you.
That said, a tone control is such a dirt-simple device that I can't imagine a "guitar repairman" being unable to get it working. You need to find someone who has a clue about basic electronics. |
I could not agree more. And I will share this with you. Many years ago, I heard a steel player tell another player who owned an Emmons P/P, with its typical tone control and tone control disable switch,
"Ya NEED to remove those parts and wire that PU straight to the jack. Ya git a LOT more power that way!"
Bless this man's heart, if he only knew, when you disable a tone control, you ARE connecting the PU straight to the jack. Plus,a tone control has nothing to do with power. The ONLY thing a passive tone circuit does is to attenuates highs in a logrithmic scale. Meaning, the higher the highs the more the attenuation.
Or 1 over 2xPIxFxC
Where F is freguency and C is the value of the capacitor; which determines the capacitive "reactance" (resistance to alternating current) of a given capacitor.
That is all it does. It has nothing to do with power. Its affect on mids and bass in the audio spectrum (20-20KHZ) is for all practical purposes, unintelligible.
When it comes to playing a musical instrument, I have nothing but the highest respect and love for great players and their gifts and this goes for even mediocre players. But when it comes to the electronic part, that is my gift and the gift of others of my ilk. "off the cuff" claims may get a lot of "dittos" and "kudos" amongst peers, but that is ALL it is.
Again, I agree with you. If a player does not want a tone control on their steel, then by all means take that sapsucker off there, and nevah look back  but don't stand in the way of those who like it and use it, because they are truly wonderful inventions. 
There is not a sweeter or more pleasing steel sound than when JB played "Steelin' the Blues" using his guitar mounted tone control. And other of his incredible recordings using same. His execution was flawless. May Jesus bless his sweet soul.
And Praise Jesus for His giving the gift to audio engineers to discover and design such blessings.
c.
_________________
A broken heart + † = a new heart. |
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Allan Munro
From:
Pennsylvania, USA and Scotland
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Posted 21 Oct 2010 7:40 pm
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| Brint Hannay wrote: |
I do not agree that a tone control on the instrument should be "ditched" or is the "spawn of the devil". ...
...That said, a tone control is such a dirt-simple device that I can't imagine a "guitar repairman" being unable to get it working. You need to find someone who has a clue about basic electronics. |
Yeah, I know - I wasn't being completely 'straight' when I used that expression. Just trying to get a raise out of the readers. However, I do have the tone pots out of circuit on my guitars and I don't even fit them on the instruments that I build unless the customer DEMANDS that I do.
I have to go along with what you say regarding a guitar repair man who can't get a passive tone control working.
Like Mr. Dixon, I spent some time as an electronics engineer (senior test engineer for a company producing PA equipment). Again, I simply set out to stir the pot a wee bit - it is a purely personal thing - I just don't like tone controls.
Regards, Allan.....
_________________
Only nuts eat squirrels.
Television is the REAL opiate of the masses! |
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