NEW!!! SC-1 Mic Preamp Kit
Status: Under Development:

May 22, 2007

Prototype power supply boards are here!!!

I'll test build one and see how it goes.

Features:

Small size!

Each voltage leg is adjustable via a Bourns trimmer. So you can exactly match voltages and fine tune it.

Lots of big caps, coupling and other caps for minimum ripple and hum... especially that 48volt line!

Two (2) on-board LEDs. You can wire one of them to go to your frontpanel, and leave the other one on the PC board as visual indicator if the board is powered up.

There are (2) solder points for the 18-0-18 power... so you can wire both preamps to go to the PSU directly instead of daisy-chaining them. Minimizes chances of ground loop differentials.

SC-1 Update

More parts arrived today. So the only thing we're missing/waiting for are the PCBs!

I've packed and sorted parts, enough for a few kits for an I.K.O. (Initial Kit Offering)

Proceeds from the initial sale will be used to buy more parts to fund the 2nd batch of kits... and the cycle goes on and on.

May 24, 2007

UPDATE

I test build one of the power supply board tonight. I like it! The individual trimmer (Bourns multi-turn, top-adjust) allow exact adjustment of each +18, -18 and +48Volt. The onboard LED lamp is also cool, you can immediately tell if the board's psu are working and powered.

Some photos:

Building in progress.... every component on the PCB is labeled with a part# and value.

POWER SUPPLY BOARD

And the finished power supply board! (I'm missing the LM337 regulator... I'm out of stock in my parts bin!!!) So I couldn't test it with the SC-1 yet. I did measure the +18 and +48V section, and adjusted the trimmer for an exact reading of the voltage regulator.

Note the RED LED lamp! You can leave one LED on board, and use the other LED2 to wire to your front panel. (Or wire both LEDs to your frontpanel!)

As you can see, this is not some cheap PSU board... lots of high value caps for excellent ripple filtering (2x 1000uf/80V and 2x 1000uf/50V). All the big caps are low-profile and also the same height.

You can fit this psu board on a 1u rack, if you use 1/4" plastic spacers to mount the board on the case.