Tuesday, May 6, 2008

Mic Preamp Specs

I think there's an audiophile or 2 listening. So now its time to brag.

I've finished designing my mic preamp on paper. Gonna order some parts and build a prototype.

So basically here's all of the specs on it:

Power Supply: 15VAC, low ripple, low noise. It will feed 48 for phantom power as well as, obviously, powering the preamp circuits. It will have a seperate auxiliary power for "noisy" things like LEDs and such.

Backplane: I'm making a modular preamp. Essentially the chassis will consist of the power supply and that's about it. Each module will plug into the backplane with a 15-pin connector.

Back panel: Each module will have an XLR in and 1/4" phone out. The in is "mic level" (see below) and the out is line-level.

Front panel: Each module will have:
- Level: The final level out
- Gain: The mic gain. The sound will be a function of gain and level of course.
- Input Impedence: 500-ohm or 2K-ohm.
- +48V Phantom Power
- High pass (select to cut at 160Hz or 1KHz)
- Low pass (select to cut at 160Hz or 1KHz)
- LED VU bar
- Clip LED

I'm going to put it all in a 2U rackmount enclosure with enough spots for up to 16 mics. I expect each module to cost me about $10 - $20 in parts, so no need to go straight to the 16.

I'm really excited to put the thing together. I look forward to doing the build. I'm coming in with a 15VAC AC/AC adapter because, well frankly I'm not comfortable doing the transformer / mains thing. Scares the hell outta me to be honest.

When all is said and done, I'll have a studio-quality preamp that would probably cost a good $10,000 if I were to buy retail. No exaggeration.

Next will be my mixer. I'm looking forward to that too. :)


Anonymous said...

But does it go to 11?

Ariesgeek said...

LOL! That's great!

Just for you, yes, I'll make it go to 11.

Anonymous said...

How many Altiod boxes did you use!! Is all this stuff green!!