What makes the biggest difference in sound quality?

If you take into account your room is a constant and suitable arena then for me speakers/amp interface is the biggest impact. Speakers first then amplification.

Thanks for the question, Ted,

Well-grounded, clean electricity is a great beginning point for a sound system.  The biggest difference in sound quality is the interaction of your loudspeaker choice(s) and the room in which they are used.

Happy New Year.  More Peace, Pin  

Run an A to B to C comparison of 3 sources on my integrated / DAC Devialet 250.

1. mac mini + Lifatec Glass Toslink
2. mac mini + Intona USB Isolator + Oyaide Continental 5S USB cable
3. Project CD Box RS2 T + Kimber Kable KCAG Coax

The test involved instant switching between the 3 systems, playing for 2 mins each for maybe an hour. Same song s running on all 3 sources.

System 3 edged slightly, with system 1 (optical) second, but the differences were very subtle. To the extend I could hardly remember them had I played the systems each on a different date.

I suspect most quality DAC makers have managed to isolate the digital input from any artefacts that may come along, to such an extend that interconnects have a much lesser impact than say power input and speaker cables.

As everyone has pretty stated everything matters and is important, but that is where i differ with most. Most feel speakers is the most important and not to say they aren’t they for sure are but i believe in putting more emphasis on the front end. Preamp, phono preamplifier or section, amp, source equipment, cartridge, turntable, tonearm, digital playback, speakers then cables. Yes quality of power and power cables also make a big difference, but speakers are down on the list for me because you’d be shocked how good even average speakers can sound with great equipment, where as great speakers with modest electronics will sound very mediocre to poor. Not to mention the importance of setup and calibration ! Speaker placement is the single most important aspect in getting good sound.

I'll go with the Linn philosophy, the source. I'll also agree with a previous post that even lower budget speakers can sound great with more upscale electronics. Lastly, power matters. A dedicated line, a good power conditioner,  and power cables do make a difference.