Prompted by the discussion above, I thought it might be interesting to see what the differences are between the SX750 and the M10 (apart from the obvious) as there are certain family resemblences.
In terms of physical format, the SX750 is about the same height as the M10, except the former has mics mounted on top while the latter has them built into the body. In other words, the main body height is about the same, but the SX750 mics project above the body. It's about 30% thinner (AAA batteries vs AA in the M10 being the key factor I guess) and half the width. The SX750 is largely controlled with buttons on the right side. If you are right handed, the most important controls fall nicely under your thumb. The topmost button is the record / record pause button.
The SX750 display is high quality LCD, and the display is laid out sideways when playing and menu setting, and vertically when recording which allows for decent size vertical meters with a margin display above them - very nicely done.
My chief reservation about the M10 relates to the built in mics. They have a good frequency response particularly at the low end, and are low noise, but because they are built into the case Sony had to use omni capsules, and I'm not aware of any recommended mic technique involving closely spaced omnis. The outcome is that the stereo image is narrow and skewed by frequency, with higher frequency sounds being more likely to appear at the sides of the image and lower frequency sounds tending to clump in the middle, leading to a muddy-sounding image with little sense of ambiance in a reverberant acoustic.
The SX750 perhaps goes to the opposite extreme. It has three cardioid capsules, one pointing forwards (when the recorder is laid flat) and the other two pointing sideways at 180 degrees. The stated purpose of the centre mic is to enable interviews or lectures to be recorded more clearly in mono. I rather hoped that Sony had done the obvious thing and implemented an MS configuration for stereo, as (apart from the slight distance apart of the side-facing capsules) the arrangement of the mics would be ideal for that method. However, careful testing shows that the centre mic is not used when the recorder is switched to stereo. Consequently, sounds coming from the centre of the soundstage arrive very much off-axis at the side-facing capsules, which is not a disaster in this context but it's an opportunity missed. But the configuration does have the advantage that it doesn't matter whether you hold it (or mount it) vertically or horizontally - it's all the same as far as the mics are concerned.
The SX750 stereo image is far superior to the M10 image, due to the mic configuration, with left/right localisation very clear, and perhaps exaggerated, though it's easy to pan the sides inwards in post production. However, the mic (and/or preamp) quality is inferior to the M10. The SX750 sound is noticeably thinner at the bottom end, although there's enough that a bit of bass lift in post production is possible to correct matters. However, that comes with a noise penalty, as there's low-mid noise as well as higher frequency hiss. How much? Well, it's perhaps better than one has a right to expect at this price point and physical size. For 'everyday' use, no big deal, but for serious recording of acoustic music, it would be a problem. But this is not a tool intended for that task.
Personally, all things taken into account, I'd be more likely to use the SX750 standalone than the M10. But I'm particularly fussy about stereo image. If low noise and a more low-end-extended frequency response matter more to you, then the M10 would be the winner.
So how does the SX750 fare with external mics? I briefly tested it with a pair of Naiant omnis and with a Rode Stereo VideoMic. Noise was higher than with the M10 (which is pretty tough competition) but again, it was usable for casual or ultra-stealthy recordings. The SX750's available gain was considerably less than that of the M10. You'd get best results with high output mics with the smaller recorder.
Line in was also slightly noisier on the SX750 than the M10, but you'd have to listen at pretty high levels to hear it. Well up to price-point expectations.
The general working of SX750 menus etc was much like the M10. There are two broad levels, the second level being accessed via a first level "detail" option, just like the M10. It's friendly and smooth in operation.
Location of the headphone output is where you'd expect the mic input to be - on the top between the mic capsules. I guess if you were operating it stand-alone in your shirt pocket (it's just the right size for that, and weighs very little) it would be handy to have the phones lead coming straight up from the top, but it does seem an odd arrangement, and ideally the mic input (which is on the side) would be at the top instead.
The SX750 comes with two CDs of software, a desk stand which has a tripod thread concealed in its base (nice surprise), a soft case, windshield, usb cable, and thowaway ear buds.
There's all sorts of other features tucked away in the menus, which the downloadable manual would explain. All in all it's an interesting general-purpose recorder - at a pinch, not unusable for concert taping on a budget, good for voice note purposes (it's Dragon certified for voice recognition) and ideal for simply keeping in your coat pocket just in case. And as I always like to record to two devices on location, it'll connect to the line out of the M10 when that's my main recorder.
Now to the samples I've prepared. Firstly, I have to confess to a boo boo - I did most of the tests with the sampling frequency set to 22050, but I don't think that's actually that important.
The downloadable file (rendered down to mp3) contains the following -
Speech recorded on the SX750 internals, no eq
Speech recorded on the M10 internals for comparison, no eq (note the difference in the stereo image!)
Same as first SX750 but with eq to try to emulate M10 sound
Speech recorded on the SX750 using Naint mics plugged straight in, 5dB of digital gain applied to match next sample
Speech recorded on the M10 using the Naint mics plugged straight in, no gain required.
SX750 line in from piano solo CD
Link - http://www.fileden.com/files/2007/9/22/1451533/Sony%20recorder%20tests.mp3
[The above is a version of a post I've added to the "TapersSection" forums]