External hard drives and sound quality

Herman,

I have some evidence to support my "hypothesis".

I have used internal, external USB, and wireless NAS storage and I have heard no differences. Nor do I hear a difference having used three different computers as music servers.

I do hear differences whenever I change any other part of my system.

So my data points support my hypothesis even though scientifically it proves nothing as you say.

Also, none of this surprises me based on my understanding of how computer and audio systems work. So I am as comfortable as I can be in my "beliefs".

You are the one bringing "scientific law" into the discussion not me.

I also would state that I do believe bumblebees can fly, so your model for predicting my beliefs is apparently not working very well.

Hopefully my limited experience in the area of question can be of benefit to someone.

So what practical advice or opinion is it that you are offering those interested in the question again besides the wisdom of realizing that nothing proves anything?

Mapman wrote: "I have used internal, external USB, and wireless NAS storage and I have heard no differences. Nor do I hear a difference having used three different computers as music servers."

Mapman - you're not going to win this argument because "somebody else might hear it". To me this is utterly nonsense that is anti-scientific and brings voodoo-harm to this forum. If we really don't know anything and have to test everything than perhaps we should test if red car has better gas millage than blue car before buying - because: "would be just as silly as you stating they don't because neither of us has any proof".

If we would pay attention to every possibility we would not have computers today.

Kijanki, I reread your post a few times and I'm not sure which side you are on, if either.

Mapman, you finally bring something to the table.

"I have used internal, external USB, and wireless NAS storage and I have heard no differences. Nor do I hear a difference having used three different computers as music servers."

Sorry if I missed it but it looked to me like everything you posted before was telling us why it shouldn't make any difference, not that you have tried it and found none. I have no problem with somebody taking a position based on their own experience even though I'm not sure your limited tests are in any way conclusive other than for you. What bothers me are those making dogmatic statements based on what they believe should be true based on "technical" matters or what they've heard from others. That's what gets us statements like:

All well designed and built amps sound the same. All wires sound the same. Transistors have lower distortion so they must sound better than tubes. Horns honk. Negative feedback lowers distortion so it must be good. All digital is the same because bits are bits. Computers have too much non-audio stuff in them to be any good for audio. And on and on and on.

.

Herman - The key is to make some sorting. Most of items you mentioned are in analog domain where things are getting extremely complicated but "bits are bits" is relatively easy to explain. Data stored on HD is retrieved without error - (not even single bit) or computers would not work. Data is extracted first to HD cache buffers and then to computer memory to end-up in FIFO output buffers. Data leaves FIFO buffer bit by bit exactly same (no matter what drive it came from). Digital data can only sound different if jitter is involved (noise in time domain). It doesn't apply here since transmission between HD and computer is synchronous (clocked). Computer has to present on its output exactly same information from the same file on different HD otherwise networks would not operate properly.

Asynchronous S/Pdif data coming from CDP could be an example of place where bit are not just a bits because of jitter.

It is remotely possible that you might hear different sound from different HD because of ground loops created by disk that affects analog audio - but it has nothing to do with type of HD. That would be pretty good example of case where experiment is useless (brings false conclusion).

People claim that jitter rejecting Benchmark DAC1 is still sensitive to transports therefore not exactly jitter rejecting. Strange part is that cheap DVD players often sound better with DAC1 (according to their testimony) than expensive transports. How is it possible? Again - wrong conclusion. Jitter rejection of Benchmark DAC1 has nothing to do with it and it is simply ability of given player to retrieve data from CD (DVD players have good tracking). It could be issue of ground loops as well.

Negative feedback that you mentioned indeed lowers distortion and sounds better but only if is used intelligently. Good designer would design amp as linear as possible to get below about 5% THD and then apply negative feedback to knock down THD to about 0.5%. Now it becomes necessary to lower input bandwidth to one that amp had before feedback was applied (to prevent TIM distortions) and voila - we got great sounding amp that nobody will buy because it has limited bandwidth and 0.5% of THD.

The issue here is the whole idea that something may in fact be happening to alter the sound that you do not understand. It is just not possible, no matter how extensive your expertise, for you to know all that could alter sound. I apologize if this is difficult for you to digest and realize it can be humbling.

To clarify again...I found the difference in sound to be subtle and not worth influencing my decision which HD to purchase. This occurred when trying different NAS units in my system. It had nothing to do with internal vs external drives rather two NAS drives. I was not aware of any faulty hardware or ground issues and am comfortable assuming there were none.

This reminds me very much of a discussion I was having on another forum trying to convince someone that digital cables can sound different. His "expertise" was making it very difficult for him to digest this fact.