Thoughts about Treble Boosters

[aziltz]

Just thinking out loud here, I think its possible to break down treble boosts into a few aspects:

A - Smaller than usual Input Cap, Rolls off more bass, setting up the accentuated treble in the frequency response.

B - Fixed gain discrete stage. 

I think the interesting thing stems from the character of the chosen discrete element and how they distort. Ge vs Si transistors, or jFETs, MOSFETs.  You could probably turn a SHO into a treble booster by fixing the gain, adjusting the input caps to cut bass and adding an output volume pot.  In fact, you could probably make a jack of all clean to treble boost by having controls for, Gain, Volume, an input cap mixer, and maybe a variable low-pass after the gain stage to roll off some harsh highs.


Has anyone experimented with this idea before?

Seems like you could make a treble booster out of your favorite clipping element.  I have a Si Treble Booster made by BBE, and its not quite my cup of tea, but i like the frequency response.  Perhaps a FET-based Treble boost would be more to my liking.

Any thoughts?

[R.G.]

Yep. Technology of the Treble Booster.

[aziltz]

Yep. Technology of the Treble Booster.

+ 1

should have mentioned i've been reading this: http://geofex.com/article_folders/rangemaster/atboost.pdf

[alanlan]

Using a small input cap is great, but I prefer a shelf response i.e. flat response up until the transition and then up to a boost level.  You can easily obtain this response by using an appropriate value cap across the source/emitter resistor in a conventional gain stage.

A small input cap produces a high pass filter rather than a shelf. 

[Gus]

alanlan  Have you seen this?
http://www.diystompboxes.com/pedals/gusOverdrive.gif

aziltz  Do a search here and old ampage for more about treble boosters

[Caferacernoc]

The runoffgroove Omega is basically what you are describing. Sweepable bass rolloff, a jfet boost for flavor, and then a mosfet follower for drive.

[JHS]

I like the TBs with a very good PNP Ge-trannie more than anything. For me nothing else has such a natural breakup and dynamic response.

JHS

[grapefruit]

I made a boost / treble boost a few years ago using a 2N7000 mosfet. IIRC I started from the rangemaster circuit and converted it for use with a mosfet. (with help from the geofex article mentioned)

It had  cap switching for normal / treble boost and was biased with the drain at about 7 volts so it clipped softly and non symmetrically. I can't find the schematic here but I think I've still got the pedal somewhere so I might try to find it and reverse engineer it. I'm not a guitarist but the guys I got to try it out liked it.

Stew.