Portable Pre

nope - I wonder if it would be feasible to add an A/D converter and an SD card for saving recordings? I just went on a trip to Asia, and was thinking it would be awesome to have something like that along with my pair of X-Q's - I could have got all kinds of wild sounds. My regular interface/computer were too big for me to pack.
 
Antichef, I'm planning on a long world wide trip in about a year and a half, and my plan is to bring an M-audio MicroTrack II and a pair of X-Q's. Should be a nice compact way to travel around and get some decent quality field recordings (hopefully :p)
 
looks cool - guess you use 1/4 in. TRS -> XLR cables for the mics?

The specs look fine - too bad it uses compact flash instead of SD. I think I could put up with that, though.
 
Don't mean to practice thread necromancy, but I just noticed that Naiant has the X-P microphone for direct connection to a PC or portable device -- the display unit has what looks like a 3.5mm TRS plug.

Does anyone know whether these require phantom power? You'd think not, if they're intended to go direct to a PC, but then they are condensers...
 
Don't mean to practice thread necromancy, but I just noticed that Naiant has the X-P microphone for direct connection to a PC or portable device -- the display unit has what looks like a 3.5mm TRS plug.

Does anyone know whether these require phantom power? You'd think not, if they're intended to go direct to a PC, but then they are condensers...

I've had that for quite a while, but it used to be on a separate page. Condensers only need high voltage to polarize the capsule, that is, if they aren't electrets which are permanently polarized. Electrets only need a small voltage to drive their FET, which is what a PC mic input is designed to do.

Anyway, many of my products are designed to run off PC mic power.

Also, this week I've been staring at the MXL Micmate. I don't like its execution, but it's a clever idea. Other than being too big, my unit seems to have an unacceptable noise. I can't tell if this is a function of a noisy USB ground, noise leaking from its DC converter, a rather unregulated USB +5V feeding the analog supply on the codec, or what, but it's definitely an oscillately-kind of sounding noise.

So I started thinking about mods, then I just thought maybe I'd build my own. MXL cleverly scratched off the label on the codec, but it wasn't too hard to figure it was one of TI's PCM29xx family. They scratched off the label on their input opamp too, which is silly. C'mon, it's an opamp, no big secret there.

Anyway, the advantage I would have other than my good looks is my mics don't need more than the 5V supply of the USB bus, so no DC converter is required. That cuts down on potential noise sources right there. Then the usual brew of quality components in a clever package, and there you go.

I'll do a few things differently. I'll have stereo ins and a headphone out, driven from a high-current opamp (more like the Micmate Pro), with the leads on a pigtail. I won't need a gain control, because the dynamic range of the converter and microphone are defined, so I can simply preset input gain at the required level. I haven't quite figured out headphone level control; it can be done digitally in the PC, but in analogland, I'd need a pot before the output buffer, and that's always a trick when using Neutrik as a form factor. An inline headphone attenuator would work, I guess. What I'd really like is to find a really good 32 ohm full-range speaker and make a mini-monitor for the ultimate in portable monitoring :cool: but I don't know if those exist.

I have to say TI is the cleverest company ever. Well, OK, after Bell Labs. I mean, one chip directly interfaces with analog I/O and USB, with no special drivers required, literally no coding of software or firmware. That's clever. I just hack together datasheet circuits, which is pretty much what MXL has done too.

Now, to work on the soldering skilzors so I can do 28-SSOP :o
 
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