An alternative to using the original CD that strikes a balance between CD (or raw WAV files) and lossy compression like AAC and MP3 would be a lossless compression (such as AAC Lossless or FLAC). That would offer the convenience while sacrificing little or no sound quality.

For what it's worth, I have experimented with iTunes playing through the 2150 using the USB port and using an Apple Airport Express which I connect w/RCA connectors into the 2150 Video ports. My conclusion is that the USB connection is far inferior to the other method.

I tried different PCs using lossless and loss formats and in every case, the USB connection sounded inferior. It doesn't make a lot of sense to me that a wireless connection should sound better than a wired one (using the same source), but I can tell you with certainty that it did in my case and I am perfectly happy with the sonic quality.

That said, I still listen to vinyl and CDs when I have the time to just sit and enjoy, but when I use music as a background for other activities, the Airport Express is a great solution from my perspective.

Thanks for the information, I tried the lossless on I tunes, (by the way I never buy my music on I tunes) it seems to be better. From what I gathered "lossless" is all the same regardless of which provider you choose, the difference is in the speed or ease of use, but the result seems to be the same, the person that suggested he uses RCA cables instead of the USB, I don't quite understand that, does it not mean that the sound card in the PC is making the conversion from digital to analogue, and is the 2150 not better equipped to make that conversion.

My real question is to what extent do the controls in windows’ control panel interfere with the signal to the receiver, I think that since the information sent through a USB connection is digital that those controls can simply be maximized and controlled through the 2150, unfortunately I am just not that technically inclined so my questions may miss the point, I would simply use CD’s or LP’s but I live in a three storey house, and I listen to music on all three floors, so carting CD’s or LP’s up and down is not practical. I just would like to optimize the computer to HI FI connection, I think this lossless may have already done so or it is getting closer in any event.

I just bought the 2150 and I like it very much, still waiting for axiom speakers, arriving today, then I intend to by a second 2150 for the third floor, all computers are on a network so it has the potential to work quite well from an access point of view, if only I can resolve quality. Thanks for listening.

Unless I'm missing something here, a digital file is a digital file. Windows should does interfere with it, since you're only only using windows as a transfer mechanism of the file to your 2150.

Yes a digital file is a digital file, but the volume, bass and treble can be controlled via windows and the 2150. When I disable my sound card the USB stops working. So I am somewhat confused as to where the digital to analogue transfere is actually taking place. I am almost certain it is the micronas chip in the 2150 but why does windows still maintain some control and given that it does should the windows settings be at maximum as you point out a digital file is a digital file so there is only more or less information is my understanding and the conversion to analogue is done by the receiver. So where in your opinion does one set the bass control on windows for example, at maximum or mid range.

I'm sure no expert here, but I can only tell you to do what I'd do myself, and that is do some trials first. I'd start with neutral(or mid if there is no neutral) tone controls, see how that plays with the 2150, and adjust from there. As far as the volume level, max would likely be best.

What media player do you use ? WMP allows you to turn off any audio effects. I'd even try different software players, I'm sure they don't all sound the same.

I empathize with your problem here, I find it kind of ironic that digital music, which was supposed to simplify our musical lives ...... it has done anything but !

Let me try to clear up the confusion.

The RR2150 is a pure analog device (i.e., it does NOT have a DAC). The computer sound card is doing the D to A conversion and passing the info via USB to the RR2150.

No 2ch receiver (that I know of) has a DAC - they are all analog devices. On the other hand, ALL multi-channel receivers sold today have DACs.

Now, the question is what happens when you connect a computer via USB to the 990? Can the 990 accept digital files and do the D to A conversion? Can it upsample the data coming thru the USB input?

(I am guessing YES - Gonk - please correct me if I am wrong!!!!).

I believe this is incorrect. USB is a digital communication interface, and as such it isn't capable of carrying analog audio. The RR2150's USB module contains a DAC as well as the other electronics that allow it to act as a sound card - the PC's sound card is not in the signal path, and the USB module itself serves as a sound card (one might even say that the entire RR2150 becomes a giant sound card when used in this manner). I know that the Model 990 works this way because I've tested it. The RR2150 has to work the same way.

This is typically true. There are of course going to be exceptions, but as a general rule stereo receivers are analog only. Surround receivers must have DAC's to function, since the surround processing is all performed in the digital domain (although I think Fosgate built a purely analog multichannel pre-amplifier a few years ago).

Yes, the 990 can apply processing and do D/A conversion for the USB input. I think the root of Carlos's question, though, is whether Windows mucks around with the audio data prior to handing it off to the 990 or RR2150. On that point, I'm just not sure - I certainly would like to be able to insure that the signal path was as straight as possible within the PC if I were using my USB input for much, but I also have spent enough time with Windows to know that it can hide a few bumps in the road when it comes to stuff like this.

Gonk is correct, USB is a digital interface, it can only transport zeroes and ones, and the RR2150 must have a DAC in its USB port to translate the zeroes and ones into something it can send to the speakers.

That said, the RR2150 (and I would suspect the 990) is dependent on the computer, and the chosen media player to take the file, whether it is WMA, Flac, AAC, MP3 or whatever, and turn it into something that the RR2150 can understand...PCM perhaps?

Otherwise, the manuals would have to list the file formats the DAC could support.

Cruise is exactly right: as with most any PC sound card, the R2150 is going to rely on the media player being used for decoding files like MP3, WMA, FLAC, and AAC (whether that's iTunes or WinAmp or Windows Media Player or...). In the case of these files, it is necessary not only for decoding but also for data management, since I don't know of any way to "play" an undecoded MP3 file to a sound card. The 990's USB input also requires the software to decode Dolby Digital or DTS bitstreams for sources such as DVD's or other video files - it wants a PCM stereo bitstream. I suspect that the RR2150 is the same way.