50s Style wiring and treble bleed cap

Collings

I use the 50s style wiring on most of my guitars. Tone pot is connected to the output lug of the volume pot as opposed to the input.

I like the way the volumes and tones work but still find them a little muddy when I reduce the volume.

I was wondering if I can still fit a treble bleed cap across the volume pot with 50s wiring and if so will it change how the controls currently work other than giving me a brighter tone when I reduce the volume.

Xsmnmy

with 50s wiring the proportion of your signal going into the tone circuit does not change as you lower the volume, what you are hearing is just that it is quieter; reducing volume does not cut highs, but it sounds like it does. If your tone is at zero you could get more highs with a no-load pot which is out of circuit in the zero position - makes for a noticeably brighter sound with p90s.
Adding a cap might do something - I don't know what, but it won't add highs.

ICBM

That isn't really true. With 50s wiring, lowering the volume does actually reduce the amount of treble going through the tone circuit, assuming you have the tone control up full - because it's staying fixed relative to the resistance of the lower part of the volume pot, which is going down, so the tone pot is effectively being turned up 'above 10'.

Reducing volume does cut highs - it's not just that it's quieter. What happens is that as you turn down the volume control, the cable capacitance which is in parallel with the lower part of the volume pot progressively acts as an extra tone control. Adding a treble-PASS cap to the volume control (NOT "treble bleed", that's what the tone control does ) counteracts this by balancing the potential divider.

So the correct cap value for the treble-pass depends to some extent on your guitar cable, but it will work just as well on 50s wiring. Where it doesn't work properly is on the 'backwards' or 'independent' volume control wiring where the pickup is connected to the rotor - it will to an extent, but it's fighting the loss of top-end as the load on the pickup decreases.

This is all because an electric guitar is a very primitive passive circuit, and everything - including the cable - interacts with everything else. From a pure electronics theory point of view it's a really poor solution - but it just sounds 'right' to most of us...

Collings

Thanks for the input. I've got some 180pf caps so I'll give it a try.

Basher

I really struggle with this.

I've tried several "treble bleed" solutions in a few of my guitars. Worst was a Gretsch Jet that would not retain any high end when rolling back the volume, regardless of the value of cap or cap/resistor combo I tried. 

I have a Tokai Tele copy that had a treble bleed cap installed that actually got brighter as I turned the volume down.

Best I've tried is the cap/resistor combo that came with the RS Guitarworks wiring kit that's in my Les Paul. It's just on the neck pickup but I can roll the volume right down and it stays clear and musical. Only problem is that the volume tapers are a bit mismatched so that, say, 3 on the bridge pickup is much quieter (or louder, can't remember) that 3 on the neck. It's no major problem though.

I'm guessing the best approach is the one taken here by John Cooper. He uses some fly leads so that he can just quickly clip/solder in different capacitor types and values to check what works with each guitar.

Xsmnmy

Sorry guys - I let you down  

but I also learned something - did some research this time and the Gibson 339 has the custom 'Memphis tone circuit' which is specifically designed to retain the guitar’s full tone when the volume is turned down. Here it is:

ICBM

That 'Memphis tone circuit' is just bog-standard 50s wiring! (Apart from using modern caps, which actually make no difference to the tone.)

You didn't let anyone down - this stuff is not all that intuitive (especially the way the resistance of the pots interacts with the often-forgotten capacitance of the guitar cable) and is not helped by marketing BS like the above .

Collings

Well I tried 180pf across each volume pot and it works a treat.

Retains just that bit of treble when I roll back the volume.

Dave_Mc

Basher said:

I'm guessing the best approach is the one taken here by John Cooper. He uses some fly leads so that he can just quickly clip/solder in different capacitor types and values to check what works with each guitar.

I haven't tried it but I remember a similar idea posted by dan erlewine on youtube I think (I think it was someone else who came up with the idea, who was in the video demonstrating it, though)- make up a bunch of different treble bleed circuits but attach them to crocodile clips, then clip and unclip them on the fly to see which sounds best in each guitar. then solder in the circuit/values which sound best.

EDIT: This one: