I am currently using the SanDisk 64GB microSDXC ("XC" not "HC") card in my Sony PCM-M10 - and it's working beautifully! SIXTY-FOUR GB!
Here's how I did it: http://www.head-fi.org/t/456327/sony-pcm-m10-as-portable-player/120#post_8727898
And here's how I use it:Sony PCM-M10 (Japan)
PCM Recorder/Player, using the unheralded Line Out from its wonderful delta-sigma DAC of proprietary Sony design (bypassing the internal headphone amp)Milian Acousitcs interconnect (USA)
SPOFC (silver-plated oxygen-free copper) Kevlar-sleeved interconnect with Switchcraft 3.5mm one straight and one rt. angle connectoriBasso PB2 Pelican (China)
headphone amplifier (quad push-pull design with balanced output) modded with 4x LME49990 op-amps in the input voltage gain stage and 4x HA5002 op-amps as buffers (for current gain), producing ~2500mW RMS (more than 80 times the power of a typical iDevice or other 30mW MP3 player) at a "vanishing low" THD+N of 0.00001% in the LME49990 op-amps. Toxic Cables Silver Poison (UK
) cryogenically-treated unidirectional UPOCC (ultra pure Ohno continuous cast) 99.99998% Silver wire headphone cables terminated for balanced output to...Audez'e LCD-2 Rev.1 (USA)
Planar Magnetic Headphones
Yes... the Sony PCM-M10 Line Out is THAT GOOD as a source! It's a wonderful portable transport for 44.1/16 rips or 96/24 hi-rez downloads, in WAV format.