12-30-2008 11:22 AM
I as a musician have only noticed the slowness on my own recordings (Songs I could play in my sleep) So When I had the opportunity to run this by some of my friends who are also musicians I did. Most of these people are not classically trained to they said yeah it sounds fne, But When I gave it to Marc Cohen, and he listened to Some of his tracks he counted it off and confirmed that it was perfect and that I was just hearing things. I think that some of the fuzes especially when they are reading from an SD card there could have a bit of a drop but nothing that the untrained or the in some cases the most trained ears can hear
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12-30-2008 11:46 AM
12-30-2008 04:27 PM
I thought I'd posted this, but can't find it, so apologies if it is here twice.
If the problem is an occasional player getting through with an uncalibrated crystal oscillator, that should also show as the clock keeping bad time.
I don't have a Fuze yet, so I tried my e200 against foobar on the PC. The big problem is getting both to start at the same time, but I managed once. Through a 6 minute song they played so close you'd think the phones and speakers were running off the same source. That was on the Sansa firmware.
Then I tried a longer play on Rockbox (because it preloads the next track so shouldn't lose time between songs). The PC and Rockbox started a little apart, so didn't sound synchronized, but stayed about the same, maybe a quarter second apart, for close to half an hour.
12-31-2008 08:01 AM
I think we all here assume that the Fuze is designed with a crystal oscillator, and therefore should have a playback speed that is accurate to about 0.001%. This is the typical accuracy of a crystal clock, and is about a thousand times more accurate that any human can distinguish as a pitch.
...but... There are other ways to design electronics, and the cost and physical size of adding a crystal oscillator may not have been deemed necessary.
In my experience generating accurate time bases with electronic circuits based on resistors and capacitors is very hard to do - and can be considerably worse than equipment of 20 years ago that based playback speed on electrical motors and rubber belts.
12-31-2008 08:23 AM
'In my experience generating accurate time bases with electronic circuits based on resistors and capacitors is very hard to do -"
Perhaps not that hard if temperature is held constant. One could probably design a clock that is very accurate if the temperature is held at some constant, like for example 25C, standard room temperature, however if the temperature is allowed to vary then it might run faster at higher temperature and slower at lower temperature. As a test, you could take a digital watch and keep it in a refrigerator(in a sealed plastic bag to protect it) for a few days and see if it ran slow. I guess even a mechanical watch might run slower at a colder temperature.
12-31-2008 08:32 AM
I am wondering about the Fuze's processor. It may not have that much spare processing power, so if someone presents interrupts for the processor(ie presses buttons or turns the scroll wheel to adjust volume), this might delay the processor slightly in it decoding. This might especially be the the case with WMA or FLAC which take much more processing power to decode than mp3. Just the interrupt to turn off the backlight or other interrupts might present somewhat of a delay.
12-31-2008 08:09 PM - edited 12-31-2008 08:22 PM
Well, now the problem has become worse. After updating to 02.01.17, now my tracks are not only slightly slower - but the pitch is slightly lower, too. This is unacceptable because I can't play my instruments against my Fuze tracks anymore without detuning them. Ughh....
I'm going to return it and if I get another that keeps pitch I'll never do an update again. All I want to do is drag mp3s onto it and I don't need to go online with it at all.
Just for details:
WinXPpro SP3 on my PC.
mp3s only of various bitrates. Some fixed, some variable.
CDex for ripping. Never a hitch before.
Some mp3s bought on Amazon.
Some mp3s converted from .wav files on PC platform-based audio recorder.
Playing only off the internal memory - no added memory cards.
All tracks on the Fuze exhibit the same defect. They are slightly slow and now slightly off pitch after my first firmware update.
Hmmm, I wonder:
Will this thing take .wav files?
I need something more professional. The Fuze is great for clowning around but for serious musicianship I'm afraid it won't cut it.
Message Edited by Arranger on 12-31-2008 11:22 PM
01-01-2009 03:48 AM
The Fuze has a real time clock, so crystal would be nice. Even if no crystal, how well it keeps time will tell you if it is off.
01-01-2009 10:06 AM
01-01-2009 10:47 AM
I created my own test mp3 file by using the voice recorder. Watching the clock I whacked a stapler to the desk at as close to a 10 minute interval as possible. Likely well within a second. I then transferred the file to the PC and viewed it with Audacity.
The voice recorder has the two "whack" sounds at about 10 minutes and 0.4 seconds apart. This could be caused by imprecision of my testing, but a longer test over 28 minutes gives about 2.4 extra seconds. This would indicate that the clock for the voice recorder is running an itsy bitsy amount too fast - but this error this too small to be audible.
Using Audacity I cut out the extra time to make the two clicks "exactly" 10 minutes apart, and then I added a pure 440 hz tone for the bulk of the 10 minute recording. This is independent of any crystal or other oscillator - simply a mathematical equation. This file was exported as MP3, ogg and wav files and put on the Fuze.
When I play the MP3 file back on the PC I can use my Korg CA-30 Chromatic tuner to measure the frequency of the tone that was artificially generated with Audacity. My tuner identifies the tone as A440 with 0 cents deviation - a little fluctuation of 1-2 cents is caused by ambient noise.
When I play the file back on the Fuze pushing the earphones up to the mic on the Korg tuner I get a pitch of A440 with about -20 cents of deviation. This is very close to the timing error of about 1.1%. I also copied wav and ogg versions of the same file to the Fuze, and when I play them back they are also 20 cents low in pitch. The time it takes to play the MP3 file from one click to the other is 10 minutes 7 seconds, consistent with a little more than a 1% speed error.
Here are two links that discuss the human perception of pitch and the "cents" scale of frequency...
Both of these sources claim that the limit of human hearing is about 5 cents. But the second goes on to say that many music students cannot hear a 10 cent difference. I must admit - I cannot hear the difference in their sample files - though the tuner picks it right up. Wikipedia claims that most normal adults can hear 25 cents difference, which is pretty much what we are looking at for my player.
The funny thing is the voice recorder is not effected, and the real time clock appears to work right. This give me hope that there is a firmware fix that can repair the issue. On the other hand, mine might be broken. Does anyone want to try my test files. It is easiest if you are also a musician and have access to a crystal based tuner, but a stopwatch will work as well.