JFET Treble Boost

[db]

For any interested parties:
This is a simple circuit which uses one pot to adjust between two possible treble boost frequencies.  You can play around with values of C5 and C6 to get what you want.  You can also increase the 47K pot to 100K or more but the control range will tend to squash up at each end.  With the pot at centre, a bit of boost is still obtained so it's all a bit of a compromise really.  It provides 20-30dB boost maximum.  It gives me what I want, i.e. some cutting edge on those solos.

You shouldn't have to adjust any resistor values for it to work as drawn but feel free to experiment...

db.

Circuit:


Vero layout:


Pics:

[tcobretti]

Welcome to the board, and nice first post!

[Dragonfly]

Very cool first post !  I might just have to build this one when I get back to Austin.

AC

[lovric]

beautiful & thorough! thanx 

[Gus]

reminds me of

NPN boost with Doug H. mod
R.G. Fet Treble Boost  back from the old ampage days during the rangemaster thread IIRC I will look for my notes.
http://www.diystompboxes.com/pedals/gusOverdrive.gif

[markm]

beautiful & thorough! thanx 

Ditto! 

[db]

I tried it out at a gig the other night and it seems to do the job alright.
My setup is 73' Tele Custom -> Mesa DC5 on the rythm channel (I don't like the lead channel as it's a bit too dark for my tastes).
A few unsuspecting people on the front row winced a bit when I kicked it in so that's a good thing I think!  The only thing I have found is that you get more overall boost with the lower frequency end of the pot i.e. anti-clockwise or clockwise depending on how it's wired.  This is simply because there is more bandwidth and hence more energy being boosted.  This can be compensated for by adding a resistor at that end i.e. so the pot wiper doesn't actually go as far as hitting the end stop electrically speaking, but as long as you know, it's not a problem.  Also, I found that I tended to use the lower frequency setting because it provides more gain which sort of questions the fundamental idea of having two settings but it may work differently for someone with a more subtle taste and perhaps cleaner sound than me. 
I don't know if other people are the same as me but I can't help turning knobs fully clockwise

Also, there's an imaginary prize for the first person to guess what the enclosure is in the picture as it's not home made.  The clues are there...

[markm]

Also, there's an imaginary prize for the first person to guess what the enclosure is in the picture as it's not home made.  The clues are there...

My guess would be a Distortion + enclosure.

[zachomega]

Nah, it's only got one knob. 

-Zach Omega

Also, there's an imaginary prize for the first person to guess what the enclosure is in the picture as it's not home made.  The clues are there...

My guess would be a Distortion + enclosure.

[markm]

Nah, it's only got one knob. 
-Zach Omega

Only one that can be seen.....
Could have drilled a new hole in the middle no?
I was going on the fact that yellow overspray can be seen on the inside!

[zachomega]

I thought the same thing...I was thinking maybe a DOD Overdrive 250 RI...But an LED hole can be seen and I don't think those have LED's.

-Zach Omega

Nah, it's only got one knob. 
-Zach Omega

Only one that can be seen.....
Could have drilled a new hole in the middle no?
I was going on the fact that yellow overspray can be seen on the inside!

[tcobretti]

The more I look at this design, the more I like it.  I may have to throw this one together next weekend and check it out.  I'm almost out of pots and I am out  of switches, so my builds have been few lately.

I need to place an order with Aron!