For more info on the Roger Mayer Octavia read this:
Octavia History - Truth revealed ?
this:
Octavia Evolution courtesy of Roger Mayer
and this:
Roger Mayer Octavia Octavio
and look at the:
Tycobrahe Octavia schematic
and the
Roger Mayer Octavia schematic

This is the wrong Helios schematic where all came from:

Here is the proof of my theory (scroll down):

analogguru

After showing you a couple of not-clones, here's a more original circuit I'm proud of. It's a parametric mid frequency eq with also bass and treble controls.
I think equalizers are very very powerful effects, altough they shouldn't be overestimated when post production is an option. Usually diy-ing a graphic eq is hindered by the amount of controls needed for a decent amount of bands, being them pots or worse, sliders. So I wanted to look for an alternative, and one which didn't feel like a...

Hi folks ,last week i trace ,a spark booster mini from a friend of mine.just only for learn how is work.
i triple check de values and the schematics.minus the switching system ,is very complicated, and we can put instead , a 3p3t switch.

spark mini.jpg

the layout , parts and pcb

SPARK MINI PCB.jpg

enjoy.
Rcustoms

Very nice midboost, i am planning to build it in a stompbox.

I've always liked the tone benders, and thought that it would be fun to build a few with differing component choices and various transistors. Over the last few months, I've made about twenty of the things - all slightly different. I've extensively played through them, and have chosen the two or three that sound best (to my ears). The very best is shown here - it's a smoothed silicon bender, and just sounds great! All the other prototypes were put into diecast boxes and given to musician friends...

Transistors are BC549B (Q1) and 2N3906 (Q2 & Q3). Transformer is 3.6:1+1. It's not mine, but I might be able to get another look at it sometime if there are questions.

Has anybody played around with the Shure Level Loc Compressor circuit before? I has popped up on a few pro audio forums ( here & here ) and I was surprised to see that it runs on a 9V single supply.

I cut out just the compressor part from irfrench's 500-series version & built it up on the breadboard. Holy squish!!! This thing is like a tone trampoline. It clamps down HARD on the signal & has a much less transparent crunch to it than other FET compressors like the Rothwell Love Squeeze or Jon...