I need a USB in for my Microsoft Surface Pro and Optical SPDIF out for my Digital Sound Processor in my car. Are there any cheap DACs with decent quality?

Current setup: --Headphones:            -HD650            -Philips X1   ---Amps:            -Darkvoice 336se            -6N2+FU32    I think I want a warm sounding dac, as I have a unmodded Asus STX which is said to be kind of warm but my graphics card is giving off a buzzing sound that...

As I am looking to build my friend a small headphone amp, I see lots of people doing trial and error with using old schematics and such.   Is there any way to pre-configure a perfect schematic without trial and error? As he is on a very low budget, but I want to build him the best amp I can on...

Would it be okay for me to put some dielectric grease on the prongs of the tube and if so is a certain kind preferred?

Sorry if this is a dumb question or if I dont word this right.   I haven't been able to find a chart or database on the tone of certain tube amp configurations.   Does anyone know of one or would it be useless?     I know alot of things come into play but it seems to me alot of people...

First thing I want to make note of is my $4000 budget and that the $4000 is a credit with amazon, so please keep all recommendations to Amazon.   I have read over 500 pages of threads and feel like I just have gone in circles.   I currently own low range headphones but want to invest in some...

Will a Schiit Magni with an Asus Xonar DX run Beyerdynamic DT 990 PRO-250 Ohm? or Should I sell the Sound card and get a DAC?   Any suggestions?   I currently use German Maestro 8.35d with the schiit magni and asus xonar dx, but just bought the dt990's

Currently I have a Asus Xonar DX  with a Schiit Magni. Should I keep what I have or should I sell my sound card and buy a schiit Modi? Not sure what I should do, currently using German Maestro 8.35D but just bought Beyerdynamic DT990 Pro 250 Ohm. Thanks

Budget: $150 but if that isn't viable then $300 I listen to a lot of EDM and Rap then I also watch alot of movies.   My question is for my German Maestro GMP 8.35D what is the best bang for my buck, internal sound card or external headphone amp?   Thanks for all help.

I have been searching but I don't exactly know how to categorize it. I want to know: what is the study of audio, in references of sound waves, spl, db, speakers, subs, tweeters, frequencies, impedance etc. Does anyone know what I mean? I know a bit but I want to acquire more knowledge...