Monday, September 1, 2008

Elrad Music Processor

One day some three years ago my friend Fokko gave me a strange and rusty black box with some knobs and jacks that his dad had found in the trash. They thought that since I am somewhat interested in electronics I might have some use for it. Boy, they were right.
Upon closer examination it turned out to be a Flanger/Phaser published in the 6/82 issue of Elrad, a german electronics magazine. (I found out because the name "Elrad Music Processor" was etched on the copper side of the PCB. Yes, that was easy.)
It features DT, ADT (double tracking, automatic double tracking), Flanger and Phaser modes with different timebases, variable speed and amount. It is triggered either with a footswitch or the button on the front panel. And oh yes, it is monaural.
The pots were totally scratchy, someone had made some modifications to it (including a crude guitar preamp of sorts) and it wasnt working that well.
I decided to restore it to the point where it would be useful to me. Some fellow from the SDIY mailinglist kindly send me a printout of the original Elrad article, but it was not that readable... especially the schematics and the component overlay for the PCB foil. Therefore, I put the whole shebang away.

Time passed, legend tells that I left the country.

Fast forward: about a month ago I re-found the flanger. I knew that the whole Elrad backissues are available on DVD, so I decided to invest 20 Euros and ordered it. Three days later I had perfectly readable schematics of the unit. With those it took about an hour (!) to get a working unit. Then I quickly (within 3 days or so... paint and glue take their time) built a 19" case out of some plywood, sheet metal (used to be a case for a CD player) and a 19" blanking panel that I veneered and stained orange.
I am quite happy with the result. The unit sounds nice, looks good and, strictly speaking, didnt cost me a cent since I had everything needed in the restauration process in my parts bin anyway. I currently use it as an insert in my mixing console.