Edit: The first released version of the "everything" PDF is now available:
Editedit: Minor corrections to pdf, now up to version 3a:
http://www.mediafire.com/?mdj2zywxndk
Layouts, instructions, suggested front panels etc.
Ta Daaaaa! :sam:
Version 2 is built, although I've already had to get stuck into it with the wire jumpers. :roll:
The biggest problem I've had is that the D4 diode in parallel with R43 and C13 upsets the final sidechain opamp stage (IC8b) and causes it to oscillate badly. See
here for sidechain schematic. The series Rxx/Cxx filter on the VCA CV input makes the opamp oscillate too, despite THAT's recommendations in their datasheets, although that could be more to do with the way the CV is tapped off the inverting terminal of IC8b. I'm also finding that I'm getting a cleaner sidechain signal (according to my scope) if I take the CV signal from the output of IC8b rather than that weird inverting-terminal arrangement.
However, I've done a couple of passes with some audio to see how it sounds. (44.1KHz, 16-bit mono WAV's in both cases):
Original untreated female vocal samples
De-essed female vocal samples
The de-essed version is done with the 902 set to 2.5KHz and knocking off 4-5dB at its highest peaks, mode switch set to "full range". Apologies for the slight background "grumbling" on the effected version - The 902 is yet to be installed in a case and it's probably picking up radiated noise from the PC.
Request for Keith, Drpat and others: Can I get you guys to download the untreated version and run it through your 902's with the same settings and see how it compares? Ta.
