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Audiophiles in Japan Are Installing Their Own Power Poles

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Re: Audiophiles in Japan Are Installing Their Own Power Poles

#401
post #396

Earlier quoted context omitted.

hdcp uses the DDC AFAIK. The data is scrambled but still RGB.

but wont decode if randomly modified

It's a stream based cipher, so you'll get the same amount of blips as you'd get with normal bit damage. Difference is probably that you can get a whole missing frame as a blip instead of just missing pixels, because the stream key operates on frames instead of single pixels.

Re: Audiophiles in Japan Are Installing Their Own Power Poles

#402
post #394

Earlier quoted context omitted.

Sure. tl;dr: As soon as the "digital domain" steps into the "physical domain", you can not guarantee a "side effects" free system. Let's start with a real-life example: I have a Macbook from 2006, which has a Firewire port. I have an external audio-interface (Onyx Satelite Pro), that has a (Logitech Z4) active speakers system connected via line-out. When I got the Onyx, I had to realize, that the delivered Firewire c…

> ... given the theory behind it, it should be perfectly reproducable. But then, I ask you, why the difference in sound? Placebo effect. 100% guaranteed. It is literally impossible for digital audio signals to degrade in any way that even vaguely aligns with your descriptions. It is analogous to using a different brand of SD card to get richer, more vibrant colours out of your digital camera. It is analogous to chang…

I wrote:

> [Digital] Signals [when not transmitted optically] get transmitted as electricity with ever changing voltages [...]

You wrote:

> Your attempt to describe how digital signals are transmitted is actually just plain wrong.

Wikipedia writes:

> A waveform [...] as a digital signal [...]. The two states are usually represented by some measurement of an electrical property: Voltage is the most common [...]

Therefore I will leave it here.

Re: Audiophiles in Japan Are Installing Their Own Power Poles

#403

Earlier quoted context omitted.

You don't understand the power of naivety, placebo effect, dreams and stupidity composed (multiply all). Not in any way intended to insult these people, I know a few (not as rich) and they simply do not want to understand the basic principles behind digital signals, error corrections etc. I know people that work in IT and still pretend that audio transmission over USB can add jitter to music and that a DAC can "open"…

I don't disagree with the point you're trying to make, but I'm not sure if USB is the best example to make that point. Case in point: when I used a USB DAC with my NUC there's an intermittent electrical noise that's actually quite audible and distracting (even when nothing is playing). I ended up switching to another cheap DAC that accepts optical input, and the noise completely disappeared. I'm not entirely sure wha…

Can confirm. Using my SPL Crimson audio interface with a cheap USB hub leads to clearly noticeable noise and distortion (particularly when silent). Connecting the interface directly to the Mac Mini removes the issue.

Re: Audiophiles in Japan Are Installing Their Own Power Poles

#404
post #396

Earlier quoted context omitted.

but wont decode if randomly modified

It's a stream based cipher, so you'll get the same amount of blips as you'd get with normal bit damage. Difference is probably that you can get a whole missing frame as a blip instead of just missing pixels, because the stream key operates on frames instead of single pixels.

You are right. I went back and read hdcp spec. Now I understand my confusion. What I experienced multiple times with hdcp and bad/low quality cable/connection was screen going blank for a short moment. I always assumed it was cryptography itself breaking apart, but the spec requires resetting connection in case of logged TMDS layer errors

" While the receiver may reach a determination sooner, the receiver must determine loss of synchronization at least by the time it has detected 50 consecutive data island packets with ECC errors. The HDCP Receiver must either assert the REAUTH_REQ bit of the RxStatus register or de-assert HDCP_HPD to the upstream transmitter once it determines loss of synchronization. "

Re: Audiophiles in Japan Are Installing Their Own Power Poles

#405
post #40

Gonna toss a related idea out there: Converting single-phase AC power to DC requires treating a lot of ripples. Maybe an audiophile should convert three-phase AC power to DC to ensure higher power quality?

This has nothing to do with 50/60 Hz ripples, the point of having a personal power transformer is to isolate from high-frequency noise.
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