newb starting on SW

[yertzl]

hey yeah. im trying to wrap my head around everything at once. and ive got the speaker workshop manual 1.0 from jay butterman. very good stuff.
anyway was wondering about this preamp for the measurement microphone.
i dont really know anything about amplifiers.
i think this preamp stops the soundcard from been fried so i want to use 1(im not very computer literate either but i can follow a manual).
anyway where does one get this preamp from.

in fact any basic start of hints would be helpful.

im going to go and build this jig now wooooot.

[yertzl]

actually if some1 could post a link to schematics of a pre-amp and testing mic that work together it would be much appreshiated.

ive done a search on diyaudio and its just info overload!

[claudio]

Hi,
the preamp is for the mic, therefore is needed for the acoustic measurements, and as nothing to do with frying the sound card: instead of building one, you can buy Behringer UB802 and the ECM8000 as microphone. They are cheap. In case you want to build a preamp, remember that if you are going to use the ECM8000 mic, it needs phantom power and a balanced input. Here there are schematics for the mic preamp, but I think it's on the Manual too:
http://mysite.verizon.net/tammie_eric/audio/audio.html

Regards,
Claudio

[yertzl]

thxs claudio.

ill probable make the preamp1 (cant pull up num#)
and still look for a mic 2 build. for they cost $US50 plus shipping.

i can buy electret mic inserts from altronics. this is the best 2.

polar pattern: omni-directional
current drain: 0.8mA max
impedance: 1kOhm+-30%
sensitivity: -60dBm+-3dB
freq response: 50-13kHz
cost: $2.30

polar pattern: omni-directional
current drain: 0.8mA max
impedance: 1kOhm+-30%
sensitivity: -55dBm+-3dB
freq response: 20-10kHz
cost: $2.30
slight diff in freq resp and sentitiviy

and ive seen some home made ones on the net cant remember where.


trying to keep costs down. half the reason i wish to build speakers

[rjb]

Try Elliot Sound Products in Australia for a simple mic preamp- he sells PC boards. Use Google

[NickZ]

Originally posted by claudio
[B]Hi,
buy Behringer UB802 /B]

Is there any reason the Behringer UB502 wouldn't work? It's cheaper-)

Nick

[claudio]

Originally posted by Nick:
Is there any reason the Behringer UB502 wouldn't work? It's cheaper-)

UB502 doesn't have phantom power.


yertzl, the most used mic capsule, for measurements, are the Panasonic WM60 and WM61; you can find them at Digikey and Monacor catalogue.
The ones you showed have limited frequency response.
If I remember well, in Linkwitz home page there is a modification for the Panasonic capsule, as well as on Elliot's page: http://sound.westhost.com/project93.htm

Regards,
Claudio

[Vikash]

http://www.madaboutsound.com/prod.asp?pname=MPK

I don't have the kits available, only the PCB's at the moment (can't find a source of the LM6134AIN opamp). But if you want to do it yourself, then the PCB is cheap as chips.

For a mic you want the Panasonic WM-61 electret. Those are on the site too. And don't worry about mods to the capsule.

If you fancy building the mic preamp pcb yourself, then look up the Wallin Mic Preamp v2.