MEMS Microphone Preamp

[spacefuzz74]

Hey all,

Just putting in this request for a MEMS mic preamp (schematic attached) in hopes that someone can draw up a vero layout for it.  Been building my way through mics/preamps in the hopes to find something that works well with an acoustic cello as well as a violin.  I'm very hopeful that these MEMS mics will solve my search, so if anyone has the ambition to draw up the preamp, I'd be eternally grateful!

Thank You!

mems_scem.pdf
MEMS-pinout2.jpg

[Neil mcNasty]

I seriously have my doubts about the quality of using "smartphone microphone technology" for this kind of task, but hey... why not try? I could be misunderstanding the technology behind MEMS...

Have you built this one yet?: The HPF Pre
It works magic on double bass with piezo pickups, so it should be quite useful for Cello as well, probably not so suited for Violin though, because of the low frequency response of the eq section.

When I've been on the road with professional string players (I've been a touring lighting guy for 20 years+), I've only seen the kind of solutions that you find in this article: http://electricfiddler.com/transducers/
I've never seen anyone using something like a electret/condenser or dynamic microphone unless they are a sound-engineer that is setting up for a full orchestra, so I would rule those out.

What I would do, is to first get a great transducer/piezo pickup, and then start building a variety of preamps for these kind of pickups.
That method works for the pro's, and is tried and tested for ages both on stage and in the studio.

Here's an idea: why not slap some suction cups on a guitar/bass pickup, and put that on your cello?
Then you would have a shitload of preamps to choose from on this site...
I did that with my Grandma's acoustic guitar, and it sounded absolutely wicked!

Also remember that Pickup position is the most important factor regarding how it sounds, not necessarily the pickup itself. This goes for all kinds of pickups...
Example: a single coil placed at the 24th fret position will always sound like a Strat in neck position, no matter what guitar and pickup brand you are dealing with.
Pickup position is alpha and omega!

I'll have a look at the schematic and see if I can get a layout out of it.
Got loads of spare time today.
See ya later...

EDIT: After checking out the opamp datasheet, I see that these are only available as SMD components, so that excludes me from making a layout out of it, unless we can find a substitute that is DIP...
Hmmmm... Just when I thought that I was able to help...

[spacefuzz74]

Thanks for the reply!

I've been experimenting with getting this cello set up for a while now...I tried piezo film pickup, electret mic (uni and omni) and piezo disc.  Piezo disc seemed to work the best.

I also have built the HPF Pre.  The man behind the design, Francis Deck, actually sent me some JFETS I couldn't find...which was very awesome of him.  I built the EchoPlex as well as the Acoustic Piezo Preamp too.  All of these preamps work work fine with the cello I have.

I have 2 piezo pickups wired parallel on the cello, and this setup works best so far.  I have the piezo discs sandwiched & epoxied between dense foam...however, the piezos are still so "hot" that i have to buffer them with a medium density foam base you see in the photo (pu02.jpg), and even then i can't even think about adding any kind of distortion/effect in the chain...instant and insane feedback.

Then i saw this:

http://www.ikmultimedia.com/products/irigacoustic/

Thought i'd give the MEMS mic a whirl...they are cheap enough.

Thanks Neil!  Just saw your edit too...let me know if you come up with any further ideas or advice!

pu01.jpg
pu02.jpg