[sdiy] Oakley HVM - VP330 and Lambda voice module

[Oakley Sound]

Hi Folks,

My latest DIY rack project is the Human Voice Module.

The HVM is an electronic audio signal modification device that attempts 
to replicate some of the sounds from two classic keyboards first seen 
and heard in 1979. The module consists of three sections, two band pass 
filter networks and one parametric equaliser. It is possible to use each 
section independently if built that way but the suggested panel design 
has them wired together so as to allow maximum flexibility with the 
smallest number of front panel controls.

The design of the bandpass filter network takes its inspiration from the 
beautiful haunting sounds of the Lambda's chorus ensemble and the 
VP-330's human voice presets. In the suggested panel design of the HVM 
these are labelled Chorus and Vox respectively. A simple toggle switch 
on the panel allows the user to switch between the two modes. The chosen 
output then goes to a wet/dry mixer control pot. This sets the mix 
between the untreated audio input and the affected sound. The output of 
this control is then fed to a parametric equaliser circuit that can 
boost (maximum +20dB) or cut (maximum -20dB) a selected frequency band 
between 50Hz and 11kHz. Bandwidth, Q, can be controlled with the 
emphasis pot and can be varied from around 1 to 25.

More details including photos, Builder's Guide and sound samples:

http://www.oakleysound.com/hvm.htm

Note: the HVM does not contain the ensemble unit from the VP-330. I will 
be working on a four channel ensemble unit shortly.

Tony