MY Custom Tektronics LA2A ...
Little extra time on my hands and looking for a new challenge, I decided to attempt to build a Tektronix LA2A. The project turned out to be more rewarding than I imagined, lots of fun getting it all together and just like bread and butter, vocals and the LA2A have really made vocal tracking rewarding.
I thought I just write some of this experience down, lots of folks to thank and a lot of fun along the way. Where to start. Well I'm a novice with electronics so I paid a few bucks for some help from David Jahnsen's "How to Build a Tube Compressor Limiter" book (Now deceased). The manual had a few short comings, required some additional research but Dave's information was all well worth it, though I couldn't have done it without folks from Prodigy Professional. They are really great and have an enormous amount of knowledge to share.
So from David's book I went into parts sourcing mode, Antique Electronic Supply, Mouser, Anthony DeMaria Labs, Par-Metal, Jensen Transformers, Leeds Electronics, Ebay and of particular note Bob at Eurotubes who has helped me on a number of projects.
First the layout, What goes where and a little help cutting holes from my next door neighbor Tim. He worked at a Molding company and had all the tools to do it right.
After mounting everything up, I just followed Dave's book and put my daughter Robyn to work. She sat down one day and was interested enough to read the book and then wanted to help out. A few soldering lessons and we were off and running.
Coming together...
Meanwhile, Robyn went off to work on the front panel with Photoshop for Dummies. We needed a Logo and a look that would be striking. I really liked the DW Fearn look. ... R&D? - Simply stands for Robyn & Dad.
The front panel was painted at my friend Bill's Auto body shop. Fire engine red and polished like a mirror. Then I found John at ArtRageous Custom Laser Engraving. Amazing stuff, looks like a big printer but it burns like a welder. Just imported my Photoshop file, few last minute sanity checks and away we went. Very affordable way of getting a pro look.
About ready to fire it up, I was side tracked learning how to build a rectifier for the VU meter. It certainly didn't like AC, the needle was freaking out not knowing what it wanted to do! Finding a suitable meter lamp was also an adventure.
Ready to go, turned it on, nothing blew up but it was kinda noisy. A little more research turned up using a few resistors to ground on the heater wires and rewiring some signal lines with shielded cable.
After that, all I could say was wow. Quiet as anything in the studio, beautiful warmth and very nice dynamic range control. Took a bit to calibrate the meter but once you get a handle on how it operates you really don't need it too precise. The meter starts out off zero but after some warm up time zooms right in.
So there it is. About 4 months of reading and working it out and its done. Cost way less than buying one and now I don't think I could do without it.