#1
Okay, I've made this very simple circuit. Here is an amusing picture of it, in an old disused aluminum casing:



This is in fact not going to be a pedal at all - it's intended use will be as a 'master volume' for my amp; it will sit in the effects loop, and thusly does not need a stomp switch.

I've not properly tested it in my effects loop yet, just in front of my practice amp. Here's how it sounds:

at 0 - there is no sound, though there is a crackle with higher gain
at 5 - this is the stage where the volume seems to have maxed
at 10 - perhaps slightly louder than 5, but with a lot bit more gain

I'm asking if there are any mods I could make to the simple circuit linked at the top to improve sound quality of the volume control, especially in respect to it being used as a master volume. Thanks in advance!
Last edited by Mathamology at Jan 8, 2009,
#2
this sounds like a awesome idea

I have a 150w amp and this would help with the crazy volumes

Guitar : Fender CIJ Mustang and a Telecaster
Amp : 76 fender champ
Pedals : BBE green screamer, Big muff, Ibanez LU20 Pedal Tuner, boss loop pedal
#3
I believe you need a buffer of some sort.

Ideally with circuits like this, you want a very high input impedance (resistance) and a very low output impedance, or else you get effects such as what you're hearing. (I think that's what's going on).

You could solve the problem with two op-amps and a suitable (~12-15v) power supply. If you want I could draw a circuit diagram?

There may be an easier way but I don't know it and I'm too tired to think of one at the moment.

Anyway, someone else will probably come along with a much better answer, there are a few people on here who are really good at electronics. I'm only a term into my degree.

EDIT: By the way I really am quite tired so I may have just made assumptions.
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Last edited by loonyguitarist at Jan 8, 2009,
#4
^ apologise for nothing, I appreciate the response

Do you not think it would be a viable option to run this passive then? I'd prefer not to have it powered, because I'm hoping to patch it to the effects loop rather than have it on my board.
#5
There may be a way, hopefully someone will come along with a few ideas. I'm afraid I can't help much more than that though.

Good luck with it
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#8
Why would you want linear rather than audio?

I should know this/be able to work this out... Damn having exams next week, lol.
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#9
Quote by loonyguitarist
I believe you need a buffer of some sort.

Ideally with circuits like this, you want a very high input impedance (resistance) and a very low output impedance, or else you get effects such as what you're hearing. (I think that's what's going on).

You could solve the problem with two op-amps and a suitable (~12-15v) power supply. If you want I could draw a circuit diagram?

There may be an easier way but I don't know it and I'm too tired to think of one at the moment.

Anyway, someone else will probably come along with a much better answer, there are a few people on here who are really good at electronics. I'm only a term into my degree.

EDIT: By the way I really am quite tired so I may have just made assumptions.

No need for a buffer. That's just making things complex which you don't need to do.

Whats the issue? It works like a crappy passive volume control, its the exact same as your guitars volume knob.

Sounds like it needs to be audio taper pot though.
#10
Quote by kurtlives91
No need for a buffer. That's just making things complex which you don't need to do.

Whats the issue? It works like a crappy passive volume control, its the exact same as your guitars volume knob.

Sounds like it needs to be audio taper pot though.


As in, a log pot instead? What resistance?
#11
Quote by kurtlives91
No need for a buffer. That's just making things complex which you don't need to do.

Whats the issue? It works like a crappy passive volume control, its the exact same as your guitars volume knob.

Sounds like it needs to be audio taper pot though.



Uhm...


Quote by kurtlives91
Sounds like it needs to be audio taper pot though.


Urhm...

Quote by kurtlives91
needs to be audio taper pot though.



Does that help?
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#12
^ No...?

I had a feeling buffers may be more complicated than needed, but it's the first thing I thought of. Are there easier ways of making it better?
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Last edited by loonyguitarist at Jan 8, 2009,
#14
Quote by Øttər
Does that help?


No.

I was only following the diagram, not really sure why the pot is linear if log deals with audio... Ah well, there's something I've learnt today!

Quote by kurtlives91
haha

The resistance isn't crucial 100K, 250K, 500K, 1M will work. Yes logarithmic.


Mmmmmmkay, I'll order a new one. I'll hang fire though, in case I have to order anything else...
#18
Quote by kurtlives91
Just a pot. 100pF cap if you want to retain highs.

can you go into more detail of what a 100pF is and how I can add it to this diagram?

this must be what you mean?
http://alexplorer.net/guitar/mods/hipass.html
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Last edited by GaijinFoot at Jan 9, 2009,
#20
The fact that you are wearing a Sesame Street shirt makes that pic better
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#21
Quote by kurtlives91
Yes

Done in guitars, amps and pedals.

I can't find any capacitors that go as low as .001. I can only find .01. think you can point me in the right direction on this site?
www.maplin.co.uk

thanks
Been in Japan since August, no fucking money left!
#25
?

your amp has a volume knob.
so does your guitar.
if you need THAT much control over your volume then invest in an actual volume pedal instead of a volume knob in a box. atleast then it'll be useful for volume swells and whatnot.

i thought the rule of thumb was certain pedals go into effects loops (like delays, reverbs, choruses, etc) and other pedals that introduce gain like boosts, distortion, overdrives, etc dont? plus theres that whole thing that effects loops arent exactly ideal for stompboxes but rather rack effects but it's your amp so do what you feel.