bluestax Posted August 29, 2006 Report Share Posted August 29, 2006 Coming to MiniDisc from DAT is a traumatic event.I find that my RH1 insists on resampling a digital input down (or up) to 44.1KHz. OK, I can understand down-sampling may be needed to allow the write system to keep up. But up-sampling??? What a waste of space!And then I find that the volume levels are also digitally adjusted. Why? Surely a digital output is optimised to the correct level. Why mess with it? Just adjust the volume at playback and leave the raw data alone.Does anybody know if Sony publish distortion figures for the resampling and volume controls? They're obviously embedded in the DSP chips in the RH1 so I'm sure that the quality is not great. I've spent a long time studying resampling techniques and other digital signal modifiers to know there's a hell of a difference between the end products.Perhaps the only way I'm going to find out is to record digitally from a CD in PCM and then transfer it to my PC and compare the result with a 'ripped' copy. I'm a bit scared of what I may find.Del-Boy Quote Link to comment Share on other sites More sharing options...
e1ghtyf1ve Posted August 29, 2006 Report Share Posted August 29, 2006 Coming to MiniDisc from DAT is a traumatic event.I find that my RH1 insists on resampling a digital input down (or up) to 44.1KHz. OK, I can understand down-sampling may be needed to allow the write system to keep up. But up-sampling??? What a waste of space!And then I find that the volume levels are also digitally adjusted. Why? Surely a digital output is optimised to the correct level. Why mess with it? Just adjust the volume at playback and leave the raw data alone.Does anybody know if Sony publish distortion figures for the resampling and volume controls? They're obviously embedded in the DSP chips in the RH1 so I'm sure that the quality is not great. I've spent a long time studying resampling techniques and other digital signal modifiers to know there's a hell of a difference between the end products.Perhaps the only way I'm going to find out is to record digitally from a CD in PCM and then transfer it to my PC and compare the result with a 'ripped' copy. I'm a bit scared of what I may find.Del-BoyThis reminds me of my first DAT trauma - watching in horror as my precious tape wound itself around the capstan and pinch roller. I finally recovered after weeks of professional counseling. Some members here would believe I've not had enough... But seriously, every format has its shortcomings, as I'm sure you'll agree. In my view, the RH1 remains unmatched (for its size) in analogue performance. At least it has digital-in, unlike the R-09.That said, I would be very curious to see the results of your comparison!cheers Quote Link to comment Share on other sites More sharing options...
ozpeter Posted August 30, 2006 Report Share Posted August 30, 2006 This comes up reasonably frequently here - some examples:-http://forums.minidisc.org/index.php?showt...amples&st=0http://forums.minidisc.org/index.php?showt...mp;hl=resampleshttp://forums.minidisc.org/index.php?showt...&hl=optical Quote Link to comment Share on other sites More sharing options...
tekdroid Posted September 2, 2006 Report Share Posted September 2, 2006 ...and there I was thinking a 44.1KHz optical input was *never* resampled.Learn something new every day. Quote Link to comment Share on other sites More sharing options...
bluestax Posted September 4, 2006 Author Report Share Posted September 4, 2006 This comes up reasonably frequently here - some examples:-http://forums.minidisc.org/index.php?showt...amples&st=0http://forums.minidisc.org/index.php?showt...mp;hl=resampleshttp://forums.minidisc.org/index.php?showt...&hl=opticalThanks for the links. I followed them and kept on going and finally came across: http://www.minidisc.org/mj_ja3es.htmlNot directly for thr RH1 but probably close enough. In this, Sony give their reasons for the resampling. All I can say is that it's pure techno-bullshit!They claim that resampling a 44.1KHz signal reduces jitter and corrects for any inacuracy in the crystal oscillator of the sending device. Now,resampling has absolutely nothing to do with jitter. It's just a case of reclocking at the receiving end. Anyway, if there is really bad jitter then it will cause bit errors that will be (hopefully) corrected by the error corection at the receiveing end.Let's look at correcting the signal due to the transmitting oscillator being at slightly the wrong frequency. Why do it? The digital output is clocked by the transmitters oscillator but the information in the signal indicates that it was originally sampled at 44.1KHz and this is independent of the frequncy at which it is transmitted. Transmitting at slightly off the correct frequency will only cause problems if you want to listen to the result in real-time. If you're just trying to make a digital copy then the transmission frequency does not matter. You could transmit at double (or half) the frequency and (provided the receiver can lock on to it) get a perfect copy at the other end. That's what digital is all about!Think about it. If the transmitter is slightly off and the 'effective' transmission rate is, say, 44.0KHz but the RH1 resamples this and converts it to 44.1KHz then every time it is played on the RH1 it will have the error that was introduced by the 'faulty' tramsmitter. Who wants that?The other claim in the document is that the distortion introduced by resampling is better than -120dB. So what? If you don't resample then the distortion is ZERO (or minus infinity in dBs).How much are these guys paid to come up with such utter twaddle?Del-Boy Quote Link to comment Share on other sites More sharing options...
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