Tapered Treble Bleed

freefrog

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Interesting, I hear about this issue a lot with fuzz pedals and buffers, what exactly creates the issue and why don't other pedals have it? And I use a Big Muff, is this as tempermental as other fuzz pedals?

In a nutshell, a Fuzz Face is based on a crude circuit with a very low input impedance.

A Big Muff includes twice more transistors, a 8 times higher input impedance and creates a much thicker/gainier/more compressed sound so it's less temperamental.
 

majdestic

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Just thought Id share my experiences with wiring in my new RS Guitarworks Vintage kit in my LP Traditional, and in the process plug the wiring solution I found. (Apologies for the length of the post, I tried to edit it down, honest)

I started by wiring it 50s as per the RS recommendation, but I found that the interaction between the tone and volume controls makes for a very finicky, hit and miss setup. Basically I found that altering the tone control alters the volume control taper. What is the point of having an RS Superpot with a custom taper when that taper is completely messed up by the tone setting? This is very noticeable when you get down to 5 or below on the tone pot. I also found that mixing the pickups on the middle setting just didnt work anywhere near as nicely as it did with the stock modern wiring, I couldnt get it to sound right.
Dont get me wrong, there are some very nice tones in there, but getting the settings right is so much more difficult the slightest over correction on a pot and youre a mile off all of a sudden. I havent tried it but I would imagine in a gig setting this could be a real pain. I can see why Gibson dont use 50s wiring any more. I know most of you guys prefer it, but it doesn't work for me.

So then I tried wiring it modern instead. Good control, but straight back into the mud again on turning down the vol, particularly noticeable on the neck pickup after hearing the 50s wiring. So I ended up with a compromise, bridge wired modern, neck wired 50s, but this wasnt great, and middle position still not useable like it was stock.

So then I started thinking about modern wiring with a treble bleed circuit. The problem with treble bleeds though is that unless it is well balanced, you can end up with some unnatural sounds. Then there are parallel or series resistance options. Parallel doesnt make a lot of sense to me, as it bleeds low frequencies through as well, and as it is in parallel with the high side of the volume pot, it messes with the volume taper again; so series would seem more sensible. Also, if you get the values wrong you can end up with the guitar getting brighter as you turn the volume down. Some people leave the resistor out altogether but this ends up producing a very tinny effect when the volume is low. Then, what happens when you want to use the tone control as well? With the tone left on 10 everything is good, adjusting the volume down brings the treble bleed into play, and the highs are retained. But if you reduce the tone as well, the treble bleed is still letting through the highs the lower you set the tone the more noticeable this is I think this is the treble sheen that people refer to sometimes when talking about treble bleeds. Doesnt do much for that woman tone setting you have to leave the vol on 10 to eliminate the effect.

I tried to come up with a solution for these issues, I was thinking about using double gang pots and all sorts of exotic options, but then I came across this (its the second post in the wiring library - not sure how to link to that though)

Jemsite - Hi-Pass Filter trick (I'm an idiot)

Basically it is modern wiring with a rearranged tone circuit to allow for a different arrangement of a treble bleed. For lack of a name, I am going to call it the tapered treble bleed because what it does is to reduce the effect of the treble bleed as the tone is turned down, by wiring it to the previously unused end of the tone pot. As the tone is reduced, the resistance in the bleed circuit increases, reducing its effect. I wish I could claim credit for it, but it was posted by FrankFalbo, so hats off to him its a very clever and simple idea. The only change I have made to it is to include a series resistor this is essential I think to limit the treble bleed from making the sound getting very tinny when the volume is very low (with tone on 10).

So why am I posting this then, if it's in the wiring library? Thing is, I cant find any evidence that anyone except for the author/inventor has ever tried it. I found a couple of references to it on different forums (posts by the author) but everybody seems to have ignored him. Hence my reason for posting this - I think it's too good to pass by. Maybe most people just dont get it, or think its too far from the usual 50s/modern wiring options. Anyway it seemed to be possibly the ideal solution to me so I decided to try it. First I just tried the standard treble bleed with a series RC with various component values. This enabled me to get the correct RC values for the basic circuit, but also confirmed to me that there are some unnatural sounds produced when you turn down both the volume and the tone. Then I re-wired to the tapered version, using one of the old tone pots as a variable resistor so I could fine tune the circuit, before putting in a fixed resistor.

And you know what IT WORKS! :) I now have what I consider to be the ideal intuitive controls, a volume control that has a perfect taper, doesnt lose the highs when you turn it down, and a tone control which only affects tone and not volume, also with a lovely smooth taper, and no nasty harmonics or treble sheen. And it sounds awesome. :thumb: I can play with the tone down at 5-6 for a normal tone, and whack it up to 10 for extra bite, and this wont have any effect on the volume or taper of the volume control, and I can use the volume without it getting muddy or getting any unwanted tonal effects. I can also mix the two pickups on the middle position just like it was before. Exactly what I was after in fact.

For me, I think this is possibly the best option for the passive volume/tone control circuit, it certainly works far better than the 50s wiring on my guitar. I recommend you try it if you arent happy in any way with your tone or controls, particularly if you don't get on with the 50s wiring and don't like mud! I'd be interested to hear if anyone else out there has tried this as well.

For those of you who are interested, I've attached a schematic, a wiring diagram and a couple of pictures of my control cavity after the mod.

The volume and tone pots are 500K, the tone caps are 0.022uF Luxe Bees, the treble bleed circuit is a 0.001uF Sprague Orange Drop cap and a 220K metal film resistor (0.6w) wired in series. If you do try it, I think you will be OK with 0.001uF caps, resistor value may vary (I think I could have gone higher (to 400K) on the bridge). If you have lower value volume pots, you will probably need a smaller resistor.

Note that normally, the tone cap would be grounded to the back of the tone pot, but because of the size of the bees, I grounded it at the top lug of the volume pot (doesnt really matter where it is grounded).
would this work in a JP wiring circuit?
 

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