Is ASIO4all really for all music servers?

I have built a PC based music server using a Asus P5N7A-VM motherboard with Intel Core 2 Quad CPU @ 2.66GHz, 4GByte RAM and Windows 7 OS. I am using iTunes as my audio player application and ripped all of my 700+ CD collection on my server using the Apple lossless music format for all CD transfers to the music server. I am using the optical S/PDIF port to feed my Benchmark DAC1 HRD D/A converter/preamp. I am using my iPod Touch as my music server remote control in my listening room.

In the May/June Absolute Sound Karl Schuster and Alan Taffel are refering to the ASIO software protocol that bypasses 'any and all OS detritus' from a PC based music server. Allan T. also indicateds that 'ASIO protocol gives the ability to dynamically adapt to the incoming source sample and bit rate which will avoid manually setting changing sample rates all the time'. My understanding of this protocol is to enjoy high sample rate/bit rate music as available on HDtracks web site without any user intervention when switching to different digital music formats.

I have a few questions:

1) Could you explain what are the main benefits in using the ASIO4all protocol?

2) Will this protocol improve audio quality on all i/o audio ports of my server?

3) Will it work with the iTunes application/Win 7 combo?

3) Any expected benefit in using ASIO4all with my current setup?


The main benefits of ASIO are for earlier versions of windows where the OS audio layer did terrible things to audio. The audio stack was re-written for windows Vista and is far better.
I doubt you'd see many benefits in using ASIO...WASAPI is now the preferred method to get bit-perfect audio to your soundcar. It does, however, force the soundcard into an exclusive session, muting all other sounds (which IMO is a good thing). It does require that you change the sampling rate manually though.
One thing - I found that the optical output from my PCs on-board soundcard to be terrible. I ended up buying an audiophile 192 (M-Audio) and it is lightyears better with an S/PDIF coax connection...
Your DAC also has USB - even that would likely sound far better than the TOSLink connection.
ASIO was designed in Windows XP days. Nowadays the Windows standard WASAPI is probably more widely used.

It will not improve anything. It will allow bypassing Windows kernel sound module called kmixer, providing less interference to the audio reproduction.

You do NOT want to use iTunes on any platform because it will resample the bitrate any incoming audio source if it does not match the native bitrate, whether you use ASIO, WASAPI, or any other driver.

Since you are on Windows 7, you want to ditch iTunes and get a real music server such as JRiver. Then use WASAPI or ASIO driver depending on your preference.
Thank you Mantisory for your input.

According to Benchmark's documentation, the DAC is insensitive to jitter coming in from different digital transport sources. I was sceptical about that comment and had same opinion about the El Cheapo TOSlink connection VS coaxial S/PDIF

I have tried the S/PDIF output from my CD player VS TOSlink out from my PC playing same music content feeding the Benchmark DAC. I could not hear any difference at all between different digital inputs after a few hours of testing. So Benchmark has a pretty well engineered jitter control circuit.

Thank you Jylee for your input. I understand your point about iTunes limitations regarding hirez formats being downsampled. In Canada there is no hirez music download sites. I am relatively content with latest CD sound quality.

I will try comparing iTunes lossles VS JRiver.

I am using USB benchmark with J River music and tweaking the asioforall helped take the system to another level. Asio DOES help.

Also I suggest you unhook everything you can, shut down all unessential services and upgrade the power supply.

(I used the CICS guide for this)

Good luck!