OT:Mic to earphone amp? (battery powered)

[Ed Snape]

In connection with my attempt to build a leak detection device for a private water company, I have mounted a microphone on a 7' pole. The idea is to lower the mic into a valve pit and contact the water cut off valve. The water system tech is able to search for and isolate leaks by opening and closing valves and judging the sound. The mic I have donated has a belt/battery pack with xlr out.

Would appreciate suggestions for a small, inexpensive, battery powered mic-to- earphone amplifier. We are presently successfully testing with a Zoom H4 recorder, but seeking something smaller and less expensive. Phantom not required. Do any MP3 players include mic pres?

Thank you, Ed

[Ian Alexander]

Ed,

Perhaps this or something else from RDL.

http://www.rdlnet.com/product.php?page=64

The spec sheet says it will run (with reduced headroom) on as little as 9vdc. Looks like street is about $123. Dunno if the output would drive an earphone.

Here's something a VO wannabe asked me about just yesterday.

http://centrance.com/products/mp/

About $150 for a mic pre, 48v phantom, a/d convertor, usb interface, and headphone amp. You could rig a battery to a usb connector and be all set.

HTH.

[Ed Snape]

Thanks Ian,

Both of these look like they would work well, although we had a lower cost in mind. The USB unit looks neat enough to add to one's remote kit.

Best,

Ed

[Cary B. Cornett]

You might manage lower cost by building it yourself from scratch, but that does not take into account the value of your time. I have seen a little 2-transistor preamp kit that comes with a cheap electret capsule (think I bought one for about $12 several years back). Add one of those tiny power amp kits to drive the headphones.... if you are very careful, you might manage it with a cost of about $50, but again you probably have half a day's work to put it together. There is also the vulnerability of any condenser mic (electret or otherwise) to moisture, but with those cheap "hobbyist" capsules spares would be cheap.

Sorry, I don't remember the name of the kit company, but a Google of "DIY electronic kits" would probably get you there...

[mikebuzz]

Look at this http://www.made-in-china.com/showroo...OO-L-200-.html

Quantity would be in order though

LAter
Buzz

[Ian Alexander]

Maybe this

http://www.sweetwater.com/store/detail/SMonitor/

50 bucks, plus a battery configured to replace the wall wart.

[Tree Leopard]

http://centrance.com/products/mp/

About $150 for a mic pre, 48v phantom, a/d convertor, usb interface, and headphone amp. You could rig a battery to a usb connector and be all set.

Ooh ... good. That solves a problem for a singer I'm working with. Thanks.

[DominicPerry]

There is also a product from Shure, just out, which competes with the Centrance one. It has the advantage of having a monitor 'mix' control, which the Centrance doesn't have. I tried the MicPort Pro and I sent it back. Hang on to your receipt.

Dominic

[Tree Leopard]

Why you no like?

[DominicPerry]

The MicPort Pro didn't have much gain to begin with (IIRC, 43dB), so not enough for a few of my dynamics, and the preamp was pretty hissy at high gain. More importantly, the zero-latency signal was always at a set proportion of the headphone volume, so it was hard to get a good balance for overdubs (clearly not an issue for Ed's use) and, most importantly, as usual, the drivers were flaky. I hate flaky drivers, nothing more irritating than finding a big glitch in the middle of a take because the drivers are cr*p.
The Shure X2U is cheaper, I have no idea how good it sounds. The Shure is also only 16bit, the Centrance, 24bit.

Dominic