New Adjustable Treble Bleed

[frets]

Hi Guys😸😸😸,

I’ve come up with a new adjustable Treble Bleed that has additional options over the V-Treb.  Mine allows for selecting a 680pF, 1nF or combined 1.680 nF capacitor(s).  It runs in series to a 100k resistor and culminates with an adjustable 100k resistor in parallel.  This configuration seems to be applicable to both single coils and Humbuckers.  But I’m wondering if the 100k in series is too much?
Here are some photos on a Volume.  I call it the Treb-Leed.

[newey]

Mar 3, 2022 13:34:14 GMT -5 frets said:

But I’m wondering if the 100k in series is too much?

You could set up a simulation in 5spice and look at a frequency response curve, and do a compare/contrast with/without the resistor, or with different values.

or, you could ask JohnH.

[unreg]

Looks nice frets!

sumgai wisely explained that Treble Bleed is “bleed through” not “bleed away”. And so, maybe, Treb-Lead would make more sense? Like, it’s leading the treble. But, regardless, cool name!

[sumgai]

Looks good so far! Now, about that wiring diagram.......

"culminates with a variable resistor in parallel" doesn't confirm how it's all hooked up.  I think that you mean the pot is in parallel with the series cap-resistor combo, but I can't be certain.  Which is to say, here's where a drawing would make it obvious, such that questions like mine become needless.

Regarding the 100kΩ fixed resistor, you might find that the value is too low.  As noted by JohnH, 120-150KΩ seems to hit a sweet spot.  But as usual, everyone's mileage varies... a lot.

HTH





sumgai

[reTrEaD]

Mar 3, 2022 13:34:14 GMT -5 frets said:

I call it the Treb-Leed.

icwutudidthar
treble
   bleed

trebleed

Treb-Leed

(Clever!)

Mar 3, 2022 13:34:14 GMT -5 frets said:

Mine allows for selecting a 680pF, 1nF or combined 1.680 nF capacitor(s).  It runs in series to a 100k resistor and culminates with an adjustable 100k resistor in parallel.  This configuration seems to be applicable to both single coils and Humbuckers.  But I’m wondering if the 100k in series is too much?

If I understand correctly, the fixed resistor and whatever capacitor value that is selected are in series (like the Kinman TB). And that series combination is in parallel with the trimpot (connected as a rheostat aka variable resistor)?


I think you'd need to GuitarFreak this. My gut is telling me, if your fixed resistor is that large, your trimpot should be much larger than 100k.

[JohnH]

Another very thoughtful and cute device!

I note that certain versions of recent Fender TB circuits also have a small series resistor (plus a parallel RC pair), I think 20k?

Maybe you have tested by ear, and that would be the best test. But all my analysis checks suggested that just a simple RC parallel combo with no series resistor is best, and it would be great to have options on the R and the C to select per preference. Your C values look useful. And wigh the ideal R being 100 to 200k, this may be best offered as a 500k preset as being a reasonably common component value.

[frets]

Thank you all. Special thanks to John. I really appreciate it. I am going to tweak the design.