External hard drives and sound quality

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.

Once people encounter something counter-intuitive like digital cable affecting the sound they tend to stretch this to every possible case. Different sound of NAS drives could be related to something else then drive itself - for instance music was ripped two times to drive and is not identical - even if this is the same song/piece, or system was just turned on while second drive was tested later when system was warm and tweeters (ferrofluid) warmed-up. In addition to this we have placebo effect. In coducted tests people often swear to hear big difference while in reality they listen to exactly same set-up.

I remember joke about Russian scientist that was removing flea legs one by one ordering it everytime to jump. When he removed last one and flea did not follow his order he wrote a note "Removing all legs makes flea deaf"
One has to be very careful with conclusions.

Kijanki, I agree with your last post but there are some things in the second to last that I take exception to. Nobody has even hinted that the drives are corrupting the data. Both you and Mapman use that as some sort of proof that the drives can't alter the sound when nobody has suggested that is the reason. It is like Mr Stacy said, I said, and even you alluded to in your last post; there are things that can affect the sound that we don't understand. Stating all hard drives sound the same because they all deliver the same bits ignores all else. OK, I said that before and yet I still get bits is bits tossed at me so evidently I'm not getting my point across.

BTW I don't use any feedback in my amps and think they sound wonderful.

So Russian fleas respond to a verbal commands? I would like to see that :>)

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All of a sudden in the last week the sound in my headset has gone to hell. Used to be absolutely great! Now, a lot of clipping or static around the edges of the music. Could my External HD be acting up or could it be the Toslink "Out" from the Mac Pro? Maybe the answer is here in this thread. I use iTunes which has always served me well.