Using Jriver to play high bitrate SACD .ISO files with DSP...or convert to Flac at lower bitrate

[attndef]

Just discovered that Jriver mac will play my .iso files from SACD's straight up and separate the tracks, which is awesome, way to go JRiver.

 

My question is: These .iso files have super high bitrates like 64/352.8, my dac (like most dacs) only handles up to 24/192. So Jriver resamples with its DSP. Would it better better practice to convert the .iso's to flac at bitrate my Dac can handle or allow Jriver to do the DSP thing.

 

any input would be great.

 

Thanks!

[Allan F]

I can't offer you a definite answer but, FWIW, I can tell you that my Luxman DAC plays native DSD files using ASIO output. It does so directly rather than using the DoP protocol, with bitstreaming set to "DSD" and "Output Format" left unchecked in J River. This results in the DSP button in Standard View turning blue, indicating direct play. Direct play is supposed to produce the best sound quality. Less processing should equal better sound. The Luxman DAC can handle 352.8, but the best sound from DSD is produced by going direct at "1 bit, 2.82MHz". All my DSD albums were ripped from SACDs to .iso images, followed by extraction to individual tracks. I should add that I am certainly no expert.

[attndef]

The Luxman DAC can handle 352.8.

 

My curiosity is that my dac, like most, does up to 24/192. So some down sampling is done with the .iso files regardless. I'm just wondering if I should do it by converting to FLAC or letting Jriver do it on the fly with its dsp studio feature. Or am I just splitting hairs here?

[One and a half]

My curiosity is that my dac, like most, does up to 24/192. So some down sampling is done with the .iso files regardless. I'm just wondering if I should do it by converting to FLAC or letting Jriver do it on the fly with its dsp studio feature. Or am I just splitting hairs here?

 

Let JRiver convert on the fly. I feel you will lose finer details of converting to FLAC or AIFF for that matter. The increase in CPU activity is benign, let the CPU do some work instead of sitting on its behind. It shouldn't do more than 15%.

[firedog]

If your server can handle it, convert to 24/176 on the fly.

You can always convert a couple of iso files to flac and see if you hear a difference between that and on the fly.

[attndef]

If your server can handle it, convert to 24/176 on the fly.

You can always convert a couple of iso files to flac and see if you hear a difference between that and on the fly.

 

I store my music files locally on my Imac (early 2009 version) with a 2 TB hard drive. I just use time machine for backups.

 

When I use Jriver to play the .iso files which are at 64bit/352.8KHz the DSP is set to convert to 176.4KHz, this uses 13-15% CPU on my machine...not to bad.

[Lowlands]

. . . . . When I use Jriver to play the .iso files which are at 64bit/352.8KHz the DSP is set to convert to 176.4KHz, this uses 13-15% CPU on my machine...not to bad.

 

I reckon the SACD ISO contains DSD files... that is something different than PCM. By default JRiver DSP engine converts DSD to PCM on the 352.8K rate. If your (PCM only it seems) DAC accepts no more than 176.4 and apply settings inside JRiver DSP accordingly (as you did), JRiver DSP will convert from DSD to 176.4k PCM.

 

Off-line conversion of DSD to PCM can be done also. I have compared on-the fly conversion by JRiver with some off-line converted flac (Saracon) of that same file (both played by JRiver). It sounded different. I remenber slightly preferring the Saracon version, for having more air / space. However, I get that same impression of various upsampling algorithms in a way that it does sound less real... And I don't know what the original sounds like (my DAC does nog accept native DSD).. All in all, DSD to PCM conversion is a great feature in JRiver. As far as I know DSD to PCM conversion has some filtering / noise shaping issues (I'm no expert) that influence sound. I also recall that some experts state that DSD to PCM conversion on PCM rates above 88.2KHz does not make a lot of sense because of that...