Lumpy's Tone Shop '73 Boost

[zosotone]

Nice sounding boost!



The '73 Boost is a treble and mid range booster derived from the preamp of a late 60's Marshall Super Lead and a small preamp modification that was reportedly made to Jimmy Page's main Marshall around mid to late 1972. The mod was a simple capacitor change in a filter network, it simply boosted the upper mid range and treble frequencies further. While the pedal is obviously Zep themed, you can cover many other tones with it. The pedal is more complex and dynamic sounding than a typical treble booster design and responds very well to your guitar's volume and tone controls.

The schematic from FSB:

[Silver Blues]

Bam.

[zosotone]

Thank you very much Silver Blues!
Boost 2 to output and volume 1 to ground, true?

[Silver Blues]

Indeed. Let me know if it works!

EDIT actually I'm silly and you can shave a column off the board. Make it a 14x11 instead and get rid of the unused holes. Sorry, lol.

[zosotone]

Don't worry, nice layout! I've posted in FSB with your permission  I'll check in the next days...

Any mod for this model? Maybe a gain pot?

[Silver Blues]

Yeah go right ahead.
Gain pot, huh... well I'm not sure where the best place to put it would be. You could take R4 and replace it with a pot (Maybe 5 or 10K) and take the source end of C3 (you may want to up that cap to 10uF or so if you want a little more hair) and connect it to R4-2. That'd be my suggestion, perhaps there's a different way.

[Kinski]

Cool! Thanks for the layout!

Are there any benefits to having an external BIAS with this boost?

[zosotone]

Verified!

[IvIark]

Nice layout SB!