Got some Nordost Valhalla cables etc at home and yes - I’ll give it a week so either the cables or I break in. Hearing a lot more detail but not convinced it’s a good thing…
Had a conversation with ChatGPT - and need someone with an electric degree to confirm this makes sense…
The gist of it is that a cheaper Wiremold powerstrip with some resistance acts as a RF trapper vs a exotic cable is letting more stuff through involving RF which is then perceived as having more detail…
Anyway - here goes in case anyone would like to comment on this… AI caveats apply / sounds convincing but might be wrong..
Got it — you want the physics of why a bit of series resistance in a power strip or cord can make things sound less bright or “relaxed,” especially with amps like the Naim 500DR.
⸻
- Think of the mains line as a giant antenna
Your wall wiring is hundreds of feet of copper acting as a big RF collector:
• It picks up switch-mode PSU noise, Wi-Fi, AM/FM, SMPS dimmers, EV chargers, solar inverters — all living way above 20 kHz.
• That noise rides on top of the 50/60 Hz AC waveform.
Your power supply sees this noise as fast voltage spikes on its AC input.
⸻
- What your amp’s power supply does
The Naim 500DR’s PSU:
1. Rectifies AC into DC with diodes → they switch on/off at the peaks of the AC waveform.
2. Charges big reservoir caps → very low impedance at low frequency, but HF spikes can sneak through before the caps absorb them.
3. Sends DC into regulated rails → good PSRR, but RF can sometimes modulate sensitive analog circuitry or output stages.
⸻
- Enter series resistance R_s
A small R_s in the line (e.g., a few tens of milliohms from a power strip, cord, or wiring) does two things:
1. Forms an RC filter with the power supply’s input capacitance C_{in}:
f_c = \frac{1}{2\pi R_s C_{in}}
At high frequencies where X_C = 1/(2\pi f C) \ll R_s, the resistor damps the spike → less HF energy reaches the transformer/diodes.
2. Damps ringing: The line + transformer + diodes can behave like an RLC tank. Too little resistance → underdamped → ringing when diodes snap on/off. Modest R_s kills the Q-factor → less HF hash.
⸻
- Why too little R_s can backfire
Ultra-low-impedance cords/strips (e.g., huge-gauge audiophile cables) minimize R_s. That reduces any HF damping:
• Diode conduction edges become sharper, more HF harmonics injected.
• Any RF on the mains couples through more directly.
Subjectively:
• Lower Rs → more HF crud → “etched,” “bright,” sometimes “detailed.”
• Higher Rs (modestly) → more damping → “relaxed,” “natural.”
But too much R_s causes voltage drop under load → sag, compression, bass loss. That’s why we want just enough to damp HF, not so much it starves the amp.
⸻
- Why the Wiremold strip works well
• Its simple bus wiring has a few tens of milliohms resistance.
• No MOVs or shunt capacitors adding HF junk.
• Enough series R to slightly decouple RF between wall and amp, without starving current at 50/60 Hz.
It’s like putting a small series resistor in a snubber network: damps HF crud, leaves fundamentals alone.
AI ends here
I’m
Now just trying out a powerline into a Nordost powerstrip …
Heck - I might just ask the AV options peeps to use the Naim
Powerline cable into a Wiremold as an experiment…
Might be better than the cryo BS they’re doing currently.. (which can be had for $12/pound of material…)
