Late in 2008, I'd been quite busy with an old friend's studio upgrade job on a 72 channel Speck M72
mixing console which needed both expansion (32 Microphone preamp boards) and a re-cap job.
(72 channels @ 10 caps/channel plus mains and effects)
Here are some pics of the console and the custom mic boards I made for it...
The scope of the project was to upgrade from the original spec, so the owner decided
to use these nice Jensen JT-115K-E mic input transformers at $90/ea
The original Mfr (Speck) has not produced these for a few years now, so I needed
to make new microphone preamp circuit boards for the console.
Here is a picture of an original Speck mic-preamp board:
the original used SESCOM transformers (no longer made) and Carbon film resistors and
electrolytic capacitors by Illinois Capacitor Co.
here is a picture of my Classic Amplification upgraded version of the mic preamp board:
I used Nichicon "Muse" electrolytic's, Panasonic and Wima film caps, Metal-film
resistors, and added on-board phantom power support.
Here are the first batch of boards ready for stuffing with parts:
after stuffing:
Here the mic preamp boards are mounted on a 24-batch of the 32 primary channels:
and here is the "client" inspecting one of his newly upgraded channel boards:
(he's an old buddy I've known since the 70's)
Well now let's see, that's 16 mic preamp boards built and mounted, and 240 capacitors
replaced, so now ...hmmm... that's only like 16 more to go and a few hundred more caps
to replace!
© 2002 Brad Burt