For sale here is one m903 headphone amp and DAC.  This is a terrific unit that I used for work, but I changed jobs and now work from home, so I no longer have need of it.  It sounds fantastic and has never given me a problem of any kind; it's in perfect working order.  The owner's manual is included as pictured, but I don't have the original box or remote control.  This unit has always been used and stored in a clean, climate-controlled, non-smoking environment.  The one you see pictured is the exact one you'll receive.

I will ship via UPS ground service to any continental US destination within one business day of payment receipt.

Thanks for looking!