Go Back   UG Community @ Ultimate-Guitar.Com > Instruments > Gear Building & Customizing
User Name  
Password
Search:

Reply
Old 12-10-2013, 11:46 AM   #1
Linkerman
UG's Tony Stark
 
Linkerman's Avatar
 
Join Date: Jan 2007
Location: Portugal
Fender Frontman volume pot

A cousin of mine is starting to learn to play guitar, so he asked if he could borrow my old Fender Frontman 15G until he decides if he wants to stick with guitar enough to justify investing on gear of his own.
I'm going to let him use it, but i'd like to fix a small problem before giving it to him: the volume knob.

The volume knob never worked properly.
  • From 0 to 1,75 the amp stays mute;
  • from 1,75 to 2,10 the volume is too low and muffled;
  • at 2,10 there's a huge jump in volume;
  • and from 2,10 onwards it's fine, the volume increases progressively.

Right now it's kinda annoying, because under 2 the volume is way too low, and over 2 the volume jumps to higher than bedroom TV levels. And that's too much for playing in an apartment, for example.

I'm guessing this is a cheap and easy fix as changing the volume pot, but i don't know what to look for -- i'm an absolute ignorant when it comes to that.


Can you please tell me how to fix this problem, so that the volume level increases gradually from 0 to 10, without jumps in volume?
Thank you very much.
__________________
Squier "VMC" Stratocaster
PRS SE Singlecut
tc electronic polytune
CMAT MODS Signa Drive
Blakemore Effects Deus Ex Machina
DIY gaussmarkov Dr. Boogey
EHX Small Clone
Mooer ShimVerb
DIY Beavis Devolt
T-REX Fuel Tank Chameleon
Ampeg GVT52-112
Linkerman is offline   Reply With Quote
Old 12-10-2013, 09:11 PM   #2
Invader Jim
Registered User
 
Invader Jim's Avatar
 
Join Date: Aug 2005
It's best to replace the pot. I'll look at my scheme to see which value you need. Which pot is it?
__________________
The Wiring Thread
Invader Jim is offline   Reply With Quote
Old 12-11-2013, 06:38 AM   #3
Linkerman
UG's Tony Stark
 
Linkerman's Avatar
 
Join Date: Jan 2007
Location: Portugal
Quote:
Originally Posted by Invader Jim
It's best to replace the pot. I'll look at my scheme to see which value you need. Which pot is it?

Thank you! It's the Normal Volume (clean channel) pot.
From what i've researched before coming to UG, i think it's a linear 50K Ω 15A...

I've read that replacing the linear pot with an audio taper pot would fix the problem. Would it?
Which value? 50K, 100K? The Drive Volume and Gain pots don't seem to have the same problem, and they're 100K Ω 30C. Would using one of those instead fix the problem?
__________________
Squier "VMC" Stratocaster
PRS SE Singlecut
tc electronic polytune
CMAT MODS Signa Drive
Blakemore Effects Deus Ex Machina
DIY gaussmarkov Dr. Boogey
EHX Small Clone
Mooer ShimVerb
DIY Beavis Devolt
T-REX Fuel Tank Chameleon
Ampeg GVT52-112
Linkerman is offline   Reply With Quote
Old 12-11-2013, 09:53 PM   #4
Invader Jim
Registered User
 
Invader Jim's Avatar
 
Join Date: Aug 2005
The Clean Volume pot is a 50k audio taper. It may just be that the pot is dirty and/or worn. The pots on my 25R are all like this. I just haven't gotten around to dealing with them.

Try quickly rotating the pot through its entire range several times to loosen any junk inside it. If it starts acting better (even a little), take it out and clean it. To clean it, spray some DeOxit inside the pot and vigorously rotate it through its entire range several times. Repeat the process once or twice. When you're finished, spray in some more DeOxit to flush it out then reinstall the pot onto the circuit board. While you're doing this, you might as well clean all the pots in the amp, as they surely aren't far behind.
__________________
The Wiring Thread
Invader Jim is offline   Reply With Quote
Old 12-12-2013, 06:02 AM   #5
Linkerman
UG's Tony Stark
 
Linkerman's Avatar
 
Join Date: Jan 2007
Location: Portugal
Quote:
Originally Posted by Invader Jim
The Clean Volume pot is a 50k audio taper.

As i said, i'm completely ignorant when it comes to electronics' specs... When i said it was a linear pot, i was just repeating what i read on another website. My mistake.

Quote:
Originally Posted by Invader Jim
It may just be that the pot is dirty and/or worn. The pots on my 25R are all like this. I just haven't gotten around to dealing with them.

Try quickly rotating the pot through its entire range several times to loosen any junk inside it. If it starts acting better (even a little), take it out and clean it. To clean it, spray some DeOxit inside the pot and vigorously rotate it through its entire range several times. Repeat the process once or twice. When you're finished, spray in some more DeOxit to flush it out then reinstall the pot onto the circuit board. While you're doing this, you might as well clean all the pots in the amp, as they surely aren't far behind.

No, the pots are all clean, don't scratch, and all work perfectly.
The only issue is really that huge volume jump at a little over 2.

If i replace the stock 50K audio taper pot with another, won't the issue remain?
What if i use a 100K instead, like the Gain/Drive Volume pots?
__________________
Squier "VMC" Stratocaster
PRS SE Singlecut
tc electronic polytune
CMAT MODS Signa Drive
Blakemore Effects Deus Ex Machina
DIY gaussmarkov Dr. Boogey
EHX Small Clone
Mooer ShimVerb
DIY Beavis Devolt
T-REX Fuel Tank Chameleon
Ampeg GVT52-112
Linkerman is offline   Reply With Quote
Old 12-24-2013, 09:41 PM   #6
timbo63
Registered User
 
timbo63's Avatar
 
Join Date: Mar 2013
Location: USA
Pots get turned a lot and can get messy, so the advice above sounds good. It might be something else, but pots are subject to mechanical wear and are cheap to replace, so that's a good place to start.

You might try disconnecting the pot with a soldering iron, and then test it with an ohm meter (you should probably just buy a meter and soldering iron if you don't have them already). Test the resistance from the center (wiper) to the outer connections. You should see the resistance increase/decrease pretty regularly (although this *should* be an audio taper so it won't change linearly). Check the resistance when the wiper is at the 50% or rotation point - it should be about 10% (or 90%) depending on which outer pin you test it to. The resistance across the outer leads should be constant (and roughly match the value on the back). If it's off 10-15%, that's normal.

That should be pretty easy to do and confirm that this is your problem. It would be a good time to cleaning step above while it's out too.
timbo63 is offline   Reply With Quote
Reply


Thread Tools Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -4. The time now is 10:15 AM.

Forum Archives / About / Terms of Use / Advertise / Contact / Ultimate-Guitar.Com © 2014
Powered by: vBulletin Version 3.0.9
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.