new 2 old tech help newbie HELP

newbie here i the UK

hi there glad i found the forum . got old  80s stereo tuner amp approx 50W o/p into big floor speakers and want use to feed in mp3 music files from an sd card player ie new tech input end. i prefer mp3 but what about wav files ??, and what kit is out there on a tight budget but will look at anything . i want to get away from moving components ie a cd device  this is a big new area to me , i know very little. also whats the big deal between mp3 and wav formats . if using windows media player can i convert too and fro from either.

So what dac devices are out there with an SD card slot to buy that will do the job, ??????

ps im into tube amps too so what gives with old and new tech there regarding SD card again ???

any help, hints sites to go, really appreciated  

i looked at the sansa clip , cheap and will have to check the audio in sockets at the back of the tuner amp i think theyre phono plug line in

then it should drive the amp like a regular pre amp or stylus pick up ??? i looked at the auna sd card reader but thats a bit expensive .

im well out of date here . im thinking in the future of driving a couple of mono block tube amps with digital input , i got one amp just need to copy it and build another !!!  DAC inputs look very interesting , ive only just scratched the surface here.

thanks

that looks nice, however im looking at a dedicated sd card slot reader with some type of filter network ie controls , i looked at the cambridge range they have dac units and a unit called the one plus , like i said i,m a real newbie to this digital game !!

ok this newbie has been doing a lot,a lot,a  searching and been here and there and wound up with a compromise as i would like to combine hi fi with portable and seem to have found a little unit its the Sansa fuze 8GB player , if i plug in to the base of the player a LOD to rca cable and then into my analogue line in at the back of my amp will i get a result ???. also i have the standard size sd cards that have been around a while , willthe sansa fuze be compatable with these . i hear the sansa,s are good little units ???

The piece of kit i have is an old Philips 22 RH 720 tuner amp. 30W per channel.

just experimenting on a tight budget here and looking for a reasonable result , any help on feeding a fuze into an analogue stereo really appreciated thanks to you all so far , i think ive found the answer, i hope !!!