DOS Hi I have an ACK DAC, it is a superb lttle DAC, very analogue sound , high resolution , I have been comparing it to the lavry 924 £ 5.5k and really there isn't a great deal in it! I ordered the 'ultra high' resolution upgrade, ( I haven't heard the standard one ) it is battery powered so you have to re-charge the battery now and again, but that isn't a problem, well worth a listen to,Keith.