Bass Contour Control-How To?

[SJ318]

Hello, Namaste, S'up, G'day,
I just saw a guy demo a "bass contour control" from a Guitar Player Fretwire online vid. And is was very cool. It seemed like it could do much to control only the "low" low of a stock tone control. It was James Nash playing a Reverend King Bolt. Is This new, proprietary, or old hat. Standard Vol.,Tone, + a bass contour control.
Whatever it is, I want it. Is it an easy mod? One I could look up? It left all the mid and highs alone and only rolled off the bottom with out touching any other control. Okay, I think I have said that twice now in a little different way.
Any thoughts or most importantly-any How To's!! Yes, I tried a search. Got Nada. Maybe I asked incorrectly.
Thank you in advance as always,
Steve Buffington

[ItsaBass]

Re: Bass Contour Control-How To?

It's very easy to do. You simply wire a cap and a pot in parallel with each other, right in line with the "hot" signal. Therefore, the hot signal has two paths it can take: through the cap, or through the pot. Which one it takes is determined by how much resistance you have dialed in on the pot. No resistance on the pot (10), and the current all goes through the pot, avoiding the cap entirely. Dial in some resistance, and the signal is split between both paths. Set it to full resistance (0), and all of the current goes through the cap. Anything that ends up being forced through the cap has the low end removed. Basically, the pot is a path that the current can take around the cap, as opposed to the pot acting as a valve that leaks current through a cap to ground (like a normal tone control).

P.S. 1M reverse-log pots are often used for these types of controls.

[blueman335]

Re: Bass Contour Control-How To?

What cap value?

[SJ318]

Re: Bass Contour Control-How To?

Thank you itsabass and blue man for responding.
I am not nearly savvy enough to to understand what you said, itsabass. Could you say it again. I know enough to wire up and build my own guitars from the guts up. So I know what a pot., cap., are, know how to solder about three combinstions that I like, including pot values , vol+tone, 5 way switch., can remake a strat vibrato stay in tune differently than Mr. Fradua but works as good and never ever breaks strings. But most of that is easy to find or use you your imagination for hands on projects like drilling a block, baseplate to tuning advantage, but that's all.
But you are a big peg up on things like that. Most of the regular guys here are smart that way. So in the words of Denzel Washington: Explain it to me like I am a 10 year old, or 4 yer old.
Thanks, I mean it,
Steve B.

[CloneRanger]

Re: Bass Contour Control-How To?

What cap value?

2200 pF or lower; 1500, 1000 pF. 500K pot.

[blueman335]

Re: Bass Contour Control-How To?

The way I reduce mids and bass, and add treble is spin-a-split. You don't need any parts, just convert the tone pot into a second volume pot, but for one coil only (you wire it same as a volume pot). As you gradually dial down one coil, the coils become increasingly unbalanced, and that adds a single coil sound, which is brighter and thinner (almost all HB's have balanced coils which reduce high-end and add mids). Unbalanced coils reduce some of that effect by producing a combination of humbucker and single coil tones, which is one of the things that made the original 1950's PAF's sound so good. When the one coil is dailed all the way down, you have coil cut (only one coil active). I'm in the process of putting spin-a-split on most of my neck HB's, as I don't like them sounding too warm or bassy. There's diagrams online for spin-a-split.

[CloneRanger]

Re: Bass Contour Control-How To?

Joe Gore raved about it for humbuckers: http://www.seymourduncan.com/tonefie...cheap-awesome/

I like it a lot in my Strat, cuts quite a bit of hum, too.

[ArtieToo]

Re: Bass Contour Control-How To?

This looks like a good place for a pic:

[Juanhanglo]

Re: Bass Contour Control-How To?

Isn't this what g&l uses on the commanche and other models?
IIRC the bass control uses a 1meg pot with a cap. There are schematics available for this. I believe g&l might have it on their site.

[idsnowdog]

Re: Bass Contour Control-How To?

Yes, this is the same circuit that G&L use. Yes, they do use a 1Meg pot. Another option is to convert one of your controls into a q-filter. I have built them from scratch but you can buy them from Bill Lawrence cheaper.

Bass Cut:

http://www.metalguitarist.org/forum/guitar-tech-electronics-diy/773-tight-control-simple-passive-bass-cut.html

Q-filter:

http://profile.ultimate-guitar.com/Invader+Jim/pictures/gear/87212/1202987

http://www.youtube.com/watch?v=YnSX1Fyy7Oc

http://www.youtube.com/watch?v=NCeLI2MeOxQ

[SJ318]

Re: Bass Contour Control-How To?

Wow,
Thank you guys very much. That is good stuff. Don't mean to come across all ass-kissy, but when you guys pipe up on something, you do a wonderful job and I very much appreciate it. Putting it on my desktop now.
sb

[blueman335]

Re: Bass Contour Control-How To?

Is there a diagram for this with two pots (just for the neck PU), a volume pot and a bass contour pot?

In the 3 pot diagram, I'm not understanding the two hot wires going to the bass pot, and I don't see it grounded.

[CloneRanger]

Re: Bass Contour Control-How To?

Is there a diagram for this with two pots (just for the neck PU), a volume pot and a bass contour pot?

In the 3 pot diagram, I'm not understanding the two hot wires going to the bass pot, and I don't see it grounded.

Nothing is shunted to ground, like it would be with your regular low-pass, parallel cap tone control. At full resistance, the signal passes through the high pass, series cap; dial in some unfiltered signal and the high-pass effect is reduced.

[ItsaBass]

Re: Bass Contour Control-How To?

Is there a diagram for this with two pots (just for the neck PU), a volume pot and a bass contour pot?

In the 3 pot diagram, I'm not understanding the two hot wires going to the bass pot, and I don't see it grounded.

My description above explains this. It isn't grounded because it doesn't need to be; that's not how it works. The control is simply in line with the hot signal. As opposed to leaking frequencies to ground in order to make them inaudible, the frequencies are dissipated instead. There are not two hot wires going to the control. Everything is forced through either the cap or the pot. If it goes through the cap, the bass is taken out of it. It's actually a simpler concept to understand than a normal tone control IMO. It's just a simple strainer and valve in parallel, both in line with the "flow," instead of a strainer in line with a valve, which leaks from the "flow" into the bilge to be pumped overboard. We are just used to seeing tone controls wired a certain way, so the bass filter seems odd to us at first.

[blueman335]

Re: Bass Contour Control-How To?

So what is the wiring with one-PU / one volume / one tone (the tone being bass contour)?