I keep being reminded of how much power cords mater

@millercarbon    I see a company offering "upgrade DC power supply wall warts".  Would these also make a difference on a turntable or phonostage?

Results are all in the details but in general, yes. Wall warts use different methods to get DC, but the one thing they all have in common is cheap parts. Cheap parts in audio equals poor sound. 

The first wall warts I upgraded were for Synergistic Research Active Shielding. I had Michael Spallone do them, because even though it was totally something I could do, he has a lot of experience doing this and has tried a lot of different diodes and caps and knows which ones work best. Hands on experience is the coin of the realm here, something to bear in mind when reading posts. So I had Spallone do it, and the difference was night and day- deeper, liquid, layered. All from a better wall wart.

Soundsmith uses wall warts for their Strain Gauge phono stage. Fantastic system, just a little light in the weight department, sounds exactly like the little wall warts don't quite have the balls for true deep extension. Or maybe its the hair thin wires they're expected to transmit the power through. Or the flimsy little connector. Probably all of that together. 

Anyway, there are several upgrade options (including the wire) and all have been tried and recommended to work by actual SG owners. Comparing costs and likely results I decided to go with a full on-board DC battery and gain stage upgrade by professional recording engineer Rens Heijnis in Belgium.

So I guess you might say this is a bit more than a better wall wart, but same idea. 

In general, if the wall wart is used to supply power to audio circuits then yes there is all kinds of room for improvement. Sometimes though this is not the case. The wall wart with the Townshend Allegri Reference preamp is used only to power the display and remote. So no difference there. But anywhere the power is drawn for signal then yes, definitely.

Same goes for the turntable motor. The Teres motor once used on my Miller Carbon turntable was upgraded over time to run on various power supplies. The better the power supply, the better the sound. Pure DC from a battery worked better than anything plugged into the wall.

The turntable motor is a key component. Actually every bit of a turntable is critically important. It’s just hardly anyone ever changes just one component part to realize it. My second turntable mod was to replace the Basis motor with a Teres. Not only the motor but the motor controller. Even the pod the motor is mounted in affects the sound. Even the bolts fastening the motor to the pod. Are washers used? What material? What torque? You think I am kidding? I have experience with each and every one of these, done one at a time so as to know what does what.
Look around, vast majority replaces the whole turntable with a (hopefully) better one. I’ve done that too. But that teaches you next to nothing compared to experience gained one incremental mod at a time. 
 

The motor doesn’t just turn at a constant rate. That’s the ideal and the way everyone thinks, but the truth is every squiggle of the groove is a drag slowing it down. The result is a pattern of acceleration and deceleration every bit as complex as the music itself. Improve the motor, the power supply to the motor, the housing and the way it is fastened, all of that and it brings greater drive and life and vibrancy to the music. You have to hear it to get it, and I have, many times.
 

One of the biggest things I’ve done is go to battery power. This eliminates a huge amount of noise riding on the AC.
So there’s your answer. The motor is incredibly sensitive to power supply quality. Anything improves that improves the sound of the whole turntable.  

Incidentally, it's not just the pc. I've upgraded the motor controller power supply as well. Converting from AC to DC battery is huge. Turntables and phono stages are great for this because current demands are low and so something like an ordinary motorcycle battery will run a turntable for days. Connected to a AC charger, something interesting happens. The turntable is then always run off the battery, but can be run with the charger on or off or completely unplugged and disconnected. Guess which one sounds best?

So even when being run off a battery, if connected to AC then ripple or RFI or whatever junk is riding on the AC gets a free ride right across the battery. 

Funny you ask, one of my very first mods was remove the black rubber pc from a Basis turntable motor and hard wire a better one. Wasn't sure it would work, and being inexperienced I used a really cheap ($75) power cord, that wasn't even worth trying to sell.

That pc on the turntable motor made about as big a difference as when it was used on amps and stuff. Since then I have done this a couple other times. Most recently was the motor on my Origin Live Sovereign.

This time I decided to use a pc that, while very expensive, had no real market value due to being a prototype. So cutting it down a bit was no big loss, and I was expecting a nice improvement. 

Instead, not so much. Turns out this particular pc was too stiff. Even trimming most of the conductors, even just the few that were left were awfully stiff. I am used to thinking in vibration terms, they had to be transmitting a lot of vibration right into the motor. 

So I tried eliminating this wire for the last few inches, and used the most flexible wire I had in house, cheap ordinary lamp cord, to go from the motor to a IEC connector just a few inches outside the motor pod. The IEC is then isolated on a rig attached to the back of the rack. Now any pc can be used.

Doing it this way finally got me the expected improvement. So the moral of the story, once again, everything matters. PC matters, and isolating the pc matters just as much. 

Had a guy over one time and it was all, Why do you do this? Why do you do that? How can those Cable Cradles do anything? Quick demo. Okay, that's amazing. 

BUT, power cords? No way!

I went to my old cables drawer, pulled out one of my many freebie black rubber power cords. "According to you, this will sound just as good as what we've been listening to?" He could see what was coming but stuck to his story. 

So I put another record on, plugged the freebie in, and let him listen. Then swapped the M101 Supernova back in. 

And swear to God, the second the needle hit the groove he says OMG! Hadn't even got to the music. Still in the lead-in groove. That's how freaking obviously better it is.

Caelin Gabriel of Shunyata was here with a couple of his early Shunyata Powersnakes, half a dozen non-audiophiles who never heard anything like this before, every single one of them had no problem recognizing the improvement. 

Wire is a component, okay? Power cord, interconnect, speaker cable. Any of em. All of em. Every bit as much a component as the amp, preamp, speaker. 

The Caelin visit was 30 years ago. That's how long this has been true. At least. If not longer.