What does bit perfect actually do? Plus other mac/rega dac help

Good question.

I was also wondering about this. What difference to the sound quality would a few imperfect bits make.

Do nothing is what I would recommend. You've got a very good system.

Just wait for a few months till all the components burn in, and you settle in with the system.

Only then look at improvements.

I suspect at this point you don't even know how good a system you have. Talking about improvements will really just get you upset.

Don't worry about vibrations etc. You're best bet is to rip losslessly and leave the music on the mac mini internal hd intself. The OS will take care of reading files in big chunks and there is very little I/O doing reads.

don't worry about bit perfect. I'd bet you won't even be able to tell 256Kbps from lossless apart. In fact you might even prefer the 256kbps.

Don't worry about the hifi. Get a few more cds with the money you save. Get some cds for your sig. other.

Enjoy your music.

> Should i upgrade the power cable to the mac ...? 

Assuming it has the same effect as it does on Naim UQ and Naim DAC then I'd upgrade the optical chord to a Wireworld SuperNova 6 before I thought about power cables. The Chord cable is fine, if you don't want to spend the money, but if you are in spending mood then the WS6 will have more positive effect in my book. Changing the power cable to a Mac Mini is not going to do much, the Mac has a switched mode PS so the best bet is to keep it away from the power feeding your Naim if at all possible. Sorry, I don't know what effects power cables have on Rega electronics. 

It won't make one iota of difference if you rip to an internal or external drive, the Mac will deliver the same bitstream, as long as you set up iTunes for bit perfect replay. 

The iTunes does not automatically produce a bit perfect output, it you output what it is set to under Audio Midi - so if you set it to 24/96 then it will up-sample. You can of course change this manual depending on which tracks you want to play and restart iTunes each time or just set it to 24/96 and live with the up-sampling - doing the second of these can cause clock drift on some DACs (no idea with the Rega as I have never seen the test output for one). If you use BitPerfect this problem goes away. BitPerfect also put tracks in memory before playing them so the Mac is a little bit less noisy. 

You can either take my advice, or worry about all the other stuff Guido is talking about.

@Guido: Let the newbie be.

> What difference to the sound quality would a few imperfect bits make.

Well lets suppose 10 out 10,000,000 bits were wrong - how could anybody live with a system know that 1/10,000 th of the music is imperfect; it'd be like playing vinyl with a spec of dust on it or listening to radio and moving about. Why would you go to all the trouble of building an anechoic chamber to live in and risk such a thing. 

Even stranger the W4S ZP90 and Meridian transport up-sample CDs to 88.2/24 and sound better than bit perfect to me. 

However, I feel BP the plug-in is beneficial for the reasons I have suggested above. 

Mango can you really not tell 256 kb/s from ALAC/AIFF? 

I think theChain was referring to the BP plug-in though, which just adjusts iTunes automatically for under £5. I was just explaining what it did. 

I'm advising not changing things too, but just saying if the changing the optical chord would be more beneficial than changing the Mac's power chord. 

- If you're sticking with itunes, rip with the MacMini (faster than using a USB drive) in AIFF format (AIFF gives you bit perfect CD rips). Make sure the CD's are clean (no finger prints etc).

- Keep the Mac Mini well away from amps/DAC and if possible, plug the MM into different mains circuit to what the audio gear is using.

- On playback avoid up or downsampling. This is especially so in itunes. For CD rips, stick with 16/44.1 (unless the DAC wants to use 24 or 32 bit; if it does, still use 44.1).

- Consider third party playback software for increased SQ. Fidelia for example uses the itunes library and Fidelia also has a iphone remote app (however it's not as comprehensive or smooth running as the itunes Remote app).

If you use iTunes rather the XLD to rip then make sure error correction is on. 

The only difference I've found between ALAC and AIFF is that AIFF uses up more disc space. 

So I advise trying both format and have a listen, if you can't tell them apart then use ALAC. 

If you decide later you chose the wrong one then it is easy to convert to the other one without any need to re-rip. 

XLD has some nice ripping features and it'll find artwork even if you are not connected to your iTunes account. 

Although I can't hear or measure any benefit from other players (iTunes BP is fine for me), they are worth trailing to see if you can hear any advantage - nothing to lose. 

Thanks for all of the replies so far guys, much appreciated. I think kit wise it seems best to keep with what I have now and them consider the supernova in a few months.

So it seems more important to ensure that I have optimised the software settings (especially as this costs nothing to do). Is there a guide or screenshots to show what the settings I need to check?

Also, once bit perfect is installed do I have to do anything else? Does it automatically load when iTunes starts? My plan is not to have the mini connected to a monitor and just to set it so iTunes loads on startup and then I can control off apple remote. So will BP always run in the background whenever iTunes loads?

All due respect to Guido's observations, there is definitely an audible difference between compressed (or so called lossless) and non-compressed files.

Storage is cheap....rip once....rip at AIFF.

I can't advise on BP sorry.