K&K Audio RCA BC-2B tube mic preamps rare pair - 2004

K&K Audio RCA BC-2B tube preamps pair, based on the RCA Consolette design, also known as “The Elvis Desk” with superior frequency response.

2RU unit, transformer-coupled with HQ input, and custom lundahl power+output transformers of unique design.

The output transformers are unpotted, surrounded by thick mu-metal shielding and open on top. Airy!

11-position gain selector switch toggles between 10-40dB of gain in 3dB steps, with a single 12ay7/6072 tube in the simple signal path. Repeatable!

These are the fastest, FATTEST, most open tube pres I’ve heard using a miniature tube type. They evoke the air of octals with a tighter transient response.

The closest comparison to another pre is the DW Fearn VT2, which is not exactly fair as they use 2 tubes to make 60dB gain. To make 60dB of gain (20min-80 max!) with these BC-2Bs you cascade them, an old school technique for low output ribbons and dynamic mikes where phantom power cannot be used. Gain-stage saturation, to taste. These also have the benefit of DI capable of handling passive and active sources, even synths!

Things the DI will make sound better:

Bass guitar

Synthesizers

Samplers

Drum machines

Most anything you can send via AUX cord

These preamps were originally intended to be a DIY kit produced by Kevin Carter (K&K Audio), who has been THE source for all things Lundahl in 21st century North America.
Included in the photos is some of our previous correspondence where he confirms specs (2kohm mic input, 300ohm output, 2Mohm DI) and lore as to why you probably won’t find another like it.

Kevin built this one, himself. Proof of concept. Zero compromises, down to the heavy machined enclosure and engraved text labeling. It has provided over 2 decades of flawless operation, within a smoke/pet-free environment.

At the end of last year, I decided it’s time to release this into the wild. In opening it up to photograph, I noticed some discolored traces on the power supply card. Not burnt so much as… browned. Upon further inspection I saw a capacitor starting to bulge at the top. No leaks. See photos. The final 4 photos show before/after component-side followed by card trace-side before/after.

Got it back from my fav local music store and tech, after 3 short weeks turnaround the card was rebuilt and back in action. Sounds better than ever! I never heard any tell-tale hums or intermittent noise, odd behavior etc, prior to visually noticing the indications of potential issue. Lucky!

NOS RCA 12ay7 tubes with the extra support rods are installed.

When they’re gone, they’re gone!

Boards of Canada sticker included free for extra mojo.

Uses standard IEC grounded power cord (not included)