More DIY sexyness.. Vari-Mu.

Another one finished sans knobs. still haven't had a chance to mill them yet.

http://groupdiy.twin-x.com/displayimage.php?pos=-319
http://groupdiy.twin-x.com/displayimage.php?pos=-318
http://groupdiy.twin-x.com/displayimage.php?pos=-317
http://groupdiy.twin-x.com/displayimage.php?pos=-316

let me know what you think

:thumb:

that design is cool! Is that another panel behind the faceplate or some kind of mesh? hard to tell from the photo.

whats the circuit inside?

dave

Hey Svart,

It's like a gorgeous piece of sculpture. Congrats!

:thumb: :thumb:

it's a piece of polycarbonate(lexan) that I wiped some acetone across to haze it. I was planning on lighting it from behind but decided it looked cheezy when I actually did it.. :roll:

thanks guys, I wanted something really different for this, not the same old thing.

It's the PRR vari-mu circuit. It works VERY well for under 100$ of parts not counting the case and front panel.

:guinness: :guinness:

Silly question, but how do you drill holes that big?

FrontpanelDesigner.. :green:

If you wanted to you could use hole-saws available at your neighborhood home center/hardware store.

:thumb:

Ok I haven't been a member here that long but....

this is the coolest DIY i have seen here on the forum :shock: :grin: :shock:

the unit wil also be well recognised at a distance....I can just hear:
"hey that's the svart varimu in that rack in the corner"..."yeah i see it ...how could anyone miss it!" ...COOL! hehe lol

can't wait to see it with the knobs...are you going to go with some stock aluminum and maye just slightly flaten one side so you can not only see where your setting is...you can feel it...that would be cool..

ALSO: PRR vari-mu under $100 parts...does this include the trafo's...or is it transformerless?

again congrats on such a wonderful design :grin:
later
ts

The PRR vari-mu design, in its original incarnation, uses a 12AU7 tube and a set of Radio Shack isolation transformers. All who have built it (not yet including me) say it works and sounds great for all its simplicity.

You can find out more from PRR's original posting:

http://music-club.rutgers.edu/headfonz/comp5/Comp5.html

and from Kent:

http://www.conditionedresponse.com/DIY/C5/index.html

Just saw a small miss drawing on kent's schematics!
Release / attack controlles are mixed up! Attack, the serial resistor is suppose to be first after the IC, then the release potentiometer in parallell with the timing cap. :wink:

> Release / attack controlles are mixed up!

Kent's version is correct.

With large release/attack ratio, it would not matter. But when attack is similar to release, "my" (simplified) configuration screws-up the threshold, Kent's does not.

Kent's has the "disadvantage that release can not be less than attack, and when similar they interact, but this is not a useful setting for speech/music limiting. If you need slow-attack fast-release for special effects, you need a fancier sidechain.