Treble Bleed on a 157

[TalismanRich]

Spent the night playing around with the H157 trying out various treble bleed circuits. I'm using that as the test mule before I pull the pots on the 535.

 

I only had 1000pF capacitors, but I had 100 and 220 ohm resistors.

 

First off was just the capacitor across the neck pickup. I found this to be a bit too thin with drop of volume. It seemed to suck all the bottom end out. Not what I was looking for.

 

Next I tried the Duncan mod with either a 100 or 220 ohm resistor in parallel with the cap. Not good... treble wasn't bad but it really messed up the volume sweep. Going from 10 to 8 produced very little change in volume. Then it would start to drop off fast.

 

That led me to try the Kinman mod with the cap and resister in series. Right now I have the 1000pF with the 220 ohm resistor. It's close, but it seems that between 10 and 8, it drops a little treble, then starts to come back again around 6-7. Below that, it starts to thin out quite a bit more than I think it should. It's definitely better than it was stock, but not quite where it should be. It seems to work better on the bridge pickup than on the neck.

 

If I can get the time later this week, I think I'll try using the 50's Les Paul wiring scheme. I might also try the Guild scheme from my S100 which is similar to the 50 LP with the tone cap going to the center post on the volume pot along with the pickup lead.

 

I'll let you know where I end up.

[Rude Dog]

Cool, I'm interested in hearing how the 50s wiring compares to the treble bleed.

 

I went to 50s wiring a few years ago and never looked back; though some don't like what it does to the tone and how it makes the volume and tone controls interactive - those are the things I like.

[Dick Seacup]

I went to 50s wiring a few years ago and never looked back; though some don't like what it does to the tone and how it makes the volume and tone controls interactive - those are the things I like.

 

My Hamer Special P90 has Vol-Vol-Tone and the vol's and tone are all interactive. Coupled with the special Hamer taper pots, it makes for some interesting tonal possibilities.

[Paul P]

I only had 1000pF capacitors, but I had 100 and 220 ohm resistors.

100-220 ohms seems awfully low. I've seen 100K+ (100,000) ohm resistors mentioned

in articles.

 

I suggest you get yourself a few more capacitors and resistors. The capacitor is

mostly responsible for the frequencies that are affected. The resistor acts as a volume

control for those frequencies and may play with the taper of the pot.

 

I haven't yet gotten around to playing with this circuit myself but I think the capacitor

will have the most noticeable effect on how the circuit sounds. Capacitors and resistors

are really cheap so why not buy a bunch and then chart the effects. You should then

be able to converge on something you really like.

 

Say 200pf steps for the capacitors. For the resistor the easiest would be to use a pot,

say a linear 100K pot, and once you've dialled in the response you like, measure the pot's

value with an ohmeter then buy the closest resistor to the value.

 

Oh, and I wouldn't place anything across a pickup. That's just throwing signal away. I

believe the cap and resistor go between the output of the pickup and the output of the

volume pot.

 

Keep us posted, I for one am very interested in this circuit.

[Rude Dog]

Could you tell em more about the special taper pots?

 

My Hamer Special P90 has Vol-Vol-Tone and the vol's and tone are all interactive. Coupled with the special Hamer taper pots, it makes for some interesting tonal possibilities.

[TalismanRich]

100-220 ohms seems awfully low. I've seen 100K+ (100,000) ohm resistors mentioned

in articles.

 

 

Now I remember why you don't start playing with something at 10:00 at night. You're exactly right... they should be 100k and 220k resistors. I've got another night's work ahead! I'm pretty sure I've got a few pots laying around, I think one was a 1000k with about a 3 turn sweep. Don't even remember why I had that one but it should give me some decent range.

 

My capacitor drawer had all the wrong values in it, and the Radio Shack... well they hardly carry anything except cell phones these days. (Remember the days when you could build anything out of parts from a Radio Shack?) Once I figure out the values, it will be time to order some Spragues to put in.

 

The other layouts are here.. http://www.dearmondguitars.com/wiring.html and here... http://www.guildguitars.com/resources/guil...ng_diagrams.php

 

My Starfire Special seems to be pretty linear in rolloff. My S100 is in the bedroom without an amp right now, but I'll pull that out in a day or two. It has humbuckers that are probably closer to the Schallers than the Dearmond Gold Tones.

 

 

Like you said, parts are cheap. Where else can you have this much fun with about $3 of parts and a soldering iron?

[TalismanRich]

Now that I'm awake, I pulled out the box of resistors. No good pots in there in the 100K+ range but got a bunch of 100K resistors. Out comes the soldering iron, the back of 157 comes off, and out come the old circuit.

 

Now to do it right, put the 100K (thanks PaulP) resistor in series with the 1000pF cap. Solder it onto the neck volume control. Plug it in.... VOILA!

 

It is so much more even there's no comparison. I've got my AW1600 set up and will try to do a comparison. If I can get the volume set, I'll crank the amp up and the guitar down then reverse to get a comparison at equal volumes.

 

Anyway, it's an easy mod, cost is about $2 and makes a world of difference. I've included a pic to show how it is hooked up.

[TalismanRich]

Hmm the pic didn't show up... let me try that again.