My 50 dollar SMSL M2 amp/dac gives a noticeable difference over the onboard audio on my macbook pro. Latest macbook as well. Dacs definitely make a difference. Expectation bias works both ways, show changes when there aren't any and not noticing changes when there are. I don't understand the aggro behind your post, why does it irk you so how people choose to spend their money? :/
I used to believe that headphone cables don't make a difference in terms of sound, but I could hear a difference on my VSonic VSD 3 when upgrading to a silver cable from a stock copper one, so I have changed my stance on that. So it can't all be voodoo. To each their own. My 0.02
My second post clarified that I was talking real dacs, like in AV receivers, not the $0.002 cost per unit crap that goes into a phone or laptop, where space and cost are the primary concerns.
My aggravation comes from the blindness of people for accepting marketing claims at face value. It's not just your money you're wasting, every time someone says a $100 usb cable sounds better than a $5 usb cable, they are contributing to the climate of ignorance that pollutes real discussion of audio equipment.
Imagine if Nvidia and ATI made graphics cards but instead of telling you how many transistors it had or how many polys it could push, they only said it made videogames look better through their secret sauce which makes the colors look more real and vibrant. It's insane the amount of garbage people will swallow with regards to audio equipment simply because it's harder to quantify. People like having hobbies and they like spending money on stuff, so there will never be a shortage of fabricated "weak links" in your "audio chain" that someone is willing to sell you an upgrade to "improve".
The part of your post I bolded is EXACTLY why it's voodoo. You heard it so it must be real? Uh, no. Experiencing a different result without any actual change is the DEFINITION of the placebo effect. I guarantee if you took two identical audio cables, sold one for $100 and sold the other for $500 with fancier packaging, you would get zero complaints because people will hear what they want to hear.
I just did a little googleing and luckily someone has already done what I am too lazy to; compile a list of tests to see if cables/amps and such actually make a difference.
http://www.head-fi.org/t/486598/testing-audiophile-claims-and-myths
A few highlights..
34. Blind test of six DACs, Stereomojo
Like the other blind as opposed to ABX tests this one found the cheapest and most expensive DAC in the final, with only a hairs width between the two in terms of sound.
A test of interconnects and speaker cables found that no one could pick out the differences between a series of wires from blister pack $2.50 to $990 speaker cable. All the results were even with approximately 50% going for the cheap and expensive options.
11 - Matrixhifi.com from Spain. ABX test of two systems. June 2006.
Two systems, one cheap (A) with a Sony DVD and Behringer amp (supported on a folding chair) with chepo cables and the other more expensive (B) with Classe, YBA, Wadia and expensive cables and proper stands were hidden behind a sheet and wired to the same speakers.
The results were;
38 persons participated on this test
14 chose the "A" system as the best sounding one
10 chose the "B" system as the best sounding one
14 were not able to hear differences or didn't choose any as the best.
16 - Sean Olive, Director of Acoustic Research Harman Int, blog on The Dishonesty of Sighted Listening Tests 2009
http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html
Research using 40 Harman employees and comparing the results of blind vs sighted tests of four loudspeakers. As with the above by fellow Harman director, sighted tests show bias that blind do not.
28. Home Cinema Fr .Com, a French test of interconnects (Google Translator used) May 2005
The cables included ones from Taralabs, VDH, Audioquest and DIY ones. The result was that no one could reliably tell a difference.
31. AV Science forum, Observations of a controlled cable test Nov 2007
A blind test between Monster cables and Opus MM, which as far as I can find is $33,000 worth of cable
http://www.avsforum.com/avs-vb/showthread.php?t=941184
but the owner of the very high end kit and cables was unable to tell the difference.
There are 50 or so tests on that page and the only one I saw that shows any sort of difference is 70% of people in one group could tell the difference between a $15 cable and a $1000 cable. Y'all should face reality and save your money. Instead of spending money on a new amp or cable or dac, buy more music, donate it to charity, get another hobby, do anything other than gleefully buy and guzzle snake oil time and time again.
