The Bluesbreaker-inspired overdrive evolution

[Transmogrifox]

I started a different thread a while ago about an experimental clipping circuit I'm playing with.  It kind of evolved into an amp-like overdrive circuit on my breadboard.  After some tweaking I have something I like relatively well.

I'm undecided but might just make the bass control hard-wired...it is nice to be able to crank it up for more metal sounds and pull it out for a bit of a clean treble boost at lower gain settings though (3-position toggle?).

On low gain settings it's a nice bluesy sound with the neck PU, and also serves as a treble boost for clean sounds...and a nice hot-output boost for driving the amp downstream. Pretty versatile.

At higher gain settings it's like pure testosterone in a box.

Anyway, here are some demos.  These are all focused on higher gain settings as I wasn't feeling very docile this evening.
The pushed-amp tone but with clarity of tone on each string that defines my mental image when I think hard-rock guitar:
http://www.cackleberrypines.net/transmogrifox/Misc/Distortion_Experiment/demo/OD_Strummed_Chords.mp3

The rest are just messing around.  Nothing special.
http://www.cackleberrypines.net/transmogrifox/Misc/Distortion_Experiment/demo/Extra_Gain_Noodling.mp3
http://www.cackleberrypines.net/transmogrifox/Misc/Distortion_Experiment/demo/Noodling1.mp3
http://www.cackleberrypines.net/transmogrifox/Misc/Distortion_Experiment/demo/Noodling2.mp3
http://www.cackleberrypines.net/transmogrifox/Misc/Distortion_Experiment/demo/Overdrive_crunch.mp3

Demos recorded through el-cheapo RadioShack microphone about 3-ft from the amp. 
Guitar->Breadboard->Amp Clean channel, all EQ knobs at 50% on amp, giving a bit of a mid-scoop.  I didn't record any this way, but it certainly sounds more "midsey" when going direct to amp FX loop return.

Thanks/creds to Jon Patton (Midwayfair) for suggesting high-shelving tone control at ~1kHz.  The actual passive shelving tone control idea was inspired/ripped from an ESP article by Rod Elliot about tone controls.  I added the bass control to bring the bottom end back into the mix -- just wanted a non-interactive way to do that.

Here is the work-in-progress schematic representing what you hear in the demos.
http://www.cackleberrypines.net/transmogrifox/Misc/Distortion_Experiment/Discrete_BluesBreaker_Aug_10_2016.png


Anyone care to breadboard, tweak and share ideas?