Volume pots... I go through them so quickly

[psychodave]

For some reason I burn up volume pots. I'm on my 3rd pot for my Charvel custom shop I got in 2016. First two were CTS and now a Bourns 82 is causing me issue. Anyone else have these issues?

 

[SpiderWars]

Do you side load the knob a lot? That's the only thing I can think of that would cause to burn thru them.

Or maybe from slamming it off too hard?

 

[scottosan]

For some reason I burn up volume pots. I'm on my 3rd pot for my Charvel custom shop I got in 2016. First two were CTS and now a Bourns 82 is causing me issue. Anyone else have these issues?

Is it just scratching/crackling? I’ve noticed that with Jose style amps with huge plate resistors on V1a, you will get some DC on the guitar pots for several seconds when you take them amp off standby, because the anode voltage is so low. I’ve notice since playing Jose type amps, that my guitar pots will crackle prematurely, not sure if the DC causes any corrosion, but Potentiometer cleaner usually restores them.

 

[psychodave]

I'm a little hard on them and turn them often, but that's about it. They cut out and are super scratchy. I cleaned the CTS pots and a shit ton of black carbon came out. They were fried. That's why I went to the Bourns sealed 82a pots. Now this one had a bunch of black coming out of the shaft. I cleaned as much away, but now two weeks later, the pot is starting to cut out.

 

[paulyc]

EVH complained about pots freezing up if they were turned too fast, I've never had it happen to me but sounds like you're in good company. scototsan just proved Jose worked on EVH's amps. lol

 

[Goat]

Never a problem. Not unless it was a faulty pot to begin with.

 

[Monomyth]

For some reason I burn up volume pots. I'm on my 3rd pot for my Charvel custom shop I got in 2016. First two were CTS and now a Bourns 82 is causing me issue. Anyone else have these issues?

Is it just scratching/crackling? I’ve noticed that with Jose style amps with huge plate resistors on V1a, you will get some DC on the guitar pots for several seconds when you take them amp off standby, because the anode voltage is so low. I’ve notice since playing Jose type amps, that my guitar pots will crackle prematurely, not sure if the DC causes any corrosion, but Potentiometer cleaner usually restores them.

This is right, Have you tried a few different amps? That’s a good place to start, if it is the amp you can resolve it with a cap at the input jack but it alters the tone which is a total bitch if you are already happy with the tone, good luck.

 

[CornNutz]

For some reason I burn up volume pots. I'm on my 3rd pot for my Charvel custom shop I got in 2016. First two were CTS and now a Bourns 82 is causing me issue. Anyone else have these issues?

Is it just scratching/crackling? I’ve noticed that with Jose style amps with huge plate resistors on V1a, you will get some DC on the guitar pots for several seconds when you take them amp off standby, because the anode voltage is so low. I’ve notice since playing Jose type amps, that my guitar pots will crackle prematurely, not sure if the DC causes any corrosion, but Potentiometer cleaner usually restores them.

This is right, Have you tried a few different amps? That’s a good place to start, if it is the amp you can resolve it with a cap at the input jack but it alters the tone which is a total bitch if you are already happy with the tone, good luck.

Yeah, perhaps you should plug a guitar cable in your amp/s input, then measure dc volts with a DMM between tip, and sleeve.

 

[skullfxr]

I have never wrecked a bourns. CTS I have gone through time to time.

 

[errrrrl]

G'damn Dave... you got some mutherfkn man hands bro! No wonder your clips always sound good Tear that shit up!

 

[lockingtuner]

For some reason I burn up volume pots. I'm on my 3rd pot for my Charvel custom shop I got in 2016. First two were CTS and now a Bourns 82 is causing me issue. Anyone else have these issues?

Is it just scratching/crackling? I’ve noticed that with Jose style amps with huge plate resistors on V1a, you will get some DC on the guitar pots for several seconds when you take them amp off standby, because the anode voltage is so low. I’ve notice since playing Jose type amps, that my guitar pots will crackle prematurely, not sure if the DC causes any corrosion, but Potentiometer cleaner usually restores them.

This is right, Have you tried a few different amps? That’s a good place to start, if it is the amp you can resolve it with a cap at the input jack but it alters the tone which is a total bitch if you are already happy with the tone, good luck.

Yeah, perhaps you should plug a guitar cable in your amp/s input, then measure dc volts with a DMM between tip, and sleeve.

In layman's terms, what do you guys suspect is happening? The amp is burning out his volume pot?

 

[scottosan]

DC on the potentiometer over time likely causes oxidation of the carbon traces
I had a conversation about this with Randall Aiken a while back and he explains

You get DC on the grid because the heater is heating up the cathode, causing it to emit electrons, which must go somewhere. It doesn't matter if the heater is run on AC or DC, it will still heat up the cathode the same.

Normally, when B+ voltage is applied, the plate will attract the electrons. However, with no B+ applied to the plate, the electrons gather in a cloud around the cathode. The grid, which is grounded through a large grid-to-ground resistor, pulls the electrons away, which causes a voltage drop across the resistor. That voltage drop is what you are measuring.

When you apply B+, the high voltage at the plate attracts the majority of the electrons, so the grid voltage returns to normal.

I also come from the camp that thinks the incorporation of a standby switch on a tube amp is unhealthy on the tubes. They exist only because users have been misinformed for such a long time and are afraid to buy an amp without a standby switch. It is not bad for tubes to apply high voltage when they aren’t warm. Because they aren’t warm, they only slowly draw current as they warm up. A typicall set of tubes lasts me 5 years of daily use and then some. Back to the issue at hand I suspect that if you turn the power on and take the amp off standby simultaneously, you’ll significantly reduce the DC on the input during start up because you’ll have voltage on the plates at the same time as the heaters preventing the voltage bleeding to grid.

 

[lockingtuner]

DC on the potentiometer over time likely causes oxidation of the carbon traces
I had a conversation about this with Randall Aiken a while back and he explains

You get DC on the grid because the heater is heating up the cathode, causing it to emit electrons, which must go somewhere. It doesn't matter if the heater is run on AC or DC, it will still heat up the cathode the same.

Normally, when B+ voltage is applied, the plate will attract the electrons. However, with no B+ applied to the plate, the electrons gather in a cloud around the cathode. The grid, which is grounded through a large grid-to-ground resistor, pulls the electrons away, which causes a voltage drop across the resistor. That voltage drop is what you are measuring.

When you apply B+, the high voltage at the plate attracts the majority of the electrons, so the grid voltage returns to normal.

Very interesting. If you removed your volume knob, would you just be relocating the problem to the pickups? Or is this a problem that's specific to this kind of part?

 

[skullfxr]

I am a no standby guy. On or off. That's it. Most of my (modern) amps are running on 10 year old tubes. My vintage Fenders mostly have what I suspect to be original or very old. I know everyone has their own idea, including people far more knowledgeable than me,but I do what I do and haven't had anything that I would call a premature failure. In the last decade I have burned up two KT88's, four E34L's, AND two sets of JJ EL84's. That's about it. That also includes some amps that were gigged.

 

[scottosan]

DC on the potentiometer over time likely causes oxidation of the carbon traces
I had a conversation about this with Randall Aiken a while back and he explains

You get DC on the grid because the heater is heating up the cathode, causing it to emit electrons, which must go somewhere. It doesn't matter if the heater is run on AC or DC, it will still heat up the cathode the same.

Normally, when B+ voltage is applied, the plate will attract the electrons. However, with no B+ applied to the plate, the electrons gather in a cloud around the cathode. The grid, which is grounded through a large grid-to-ground resistor, pulls the electrons away, which causes a voltage drop across the resistor. That voltage drop is what you are measuring.

When you apply B+, the high voltage at the plate attracts the majority of the electrons, so the grid voltage returns to normal.

Very interesting. If you removed your volume knob, would you just be relocating the problem to the pickups? Or is this a problem that's specific to this kind of part?

You would never notice the issue of the pots were removed.

 

[psychodave]

I measured for DC When first turning on my CCV as well as when taking it off of standby. My fluke read .002 DC volts. Never changed.

 

[311boogieman]

DC on the potentiometer over time likely causes oxidation of the carbon traces
I had a conversation about this with Randall Aiken a while back and he explains

You get DC on the grid because the heater is heating up the cathode, causing it to emit electrons, which must go somewhere. It doesn't matter if the heater is run on AC or DC, it will still heat up the cathode the same.

Normally, when B+ voltage is applied, the plate will attract the electrons. However, with no B+ applied to the plate, the electrons gather in a cloud around the cathode. The grid, which is grounded through a large grid-to-ground resistor, pulls the electrons away, which causes a voltage drop across the resistor. That voltage drop is what you are measuring.

When you apply B+, the high voltage at the plate attracts the majority of the electrons, so the grid voltage returns to normal.

I also come from the camp that thinks the incorporation of a standby switch on a tube amp is unhealthy on the tubes. They exist only because users have been misinformed for such a long time and are afraid to buy an amp without a standby switch. It is not bad for tubes to apply high voltage when they aren’t warm. Because they aren’t warm, they only slowly draw current as they warm up. A typicall set of tubes lasts me 5 years of daily use and then some. Back to the issue at hand I suspect that if you turn the power on and take the amp off standby simultaneously, you’ll significantly reduce the DC on the input during start up because you’ll have voltage on the plates at the same time as the heaters preventing the voltage bleeding to grid.

Sorry to hear about your pot Dave but this gave me wood.

 

[CornNutz]

I also come from the camp that thinks the incorporation of a standby switch on a tube amp is unhealthy on the tubes. They exist only because users have been misinformed for such a long time and are afraid to buy an amp without a standby switch. It is not bad for tubes to apply high voltage when they aren’t warm. Because they aren’t warm, they only slowly draw current as they warm up. A typicall set of tubes lasts me 5 years of daily use and then some.

While on the standby switch subject. It was introduced to protect the filter caps. As we know the tubes do not conduct until the cathode is warmed up, and we know during this "warm up" time the PT is putting out higher voltage since it's not yet loaded. If the filter caps are not well over rated they will be over volted causing damage over time, and premature failure.

This is less of a concern in modern times because the cost of higher voltage caps are not as cost prohibitive, and size constrained as they were in the old days.

Now that being said, I've seen some modern amps that I'm pretty sure will have over voltage cap damage if you fail to use the standby switch.

 

[Braciola]

For some reason I burn up volume pots. I'm on my 3rd pot for my Charvel custom shop I got in 2016. First two were CTS and now a Bourns 82 is causing me issue. Anyone else have these issues?

I use these -

https://www.vintageinspiredpickups.com/vipots

 

[blackie13]

After all those years...
Psychodavee 's tone is not the boutique klons clones...or the 2203's 6550...or the g1230 annies...or the DA pickup...

It's the f@cked up pot !!!

That's nice...