Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Computer Audio via USB Convertor to G61R/DSP5200's

Hi Everyone,

I have been running my system Via computer based audio for some time now. The software I use J river is setup to give bit perfect out to Meridian G61R. I also play Bluray and various high-def video files with great results.

When I first got the 5200's and ran them in I was overwhelmed by how good they sounded compared to my previous DSP5000's. With bit perfect output from the computer I thought it couldn`t get any better.

I have been fairly happy with the results until:

I recently setup an old Marantz CD 63 CD player and compared to the PC optical out the difference is quite dramatic(in Marantz favour).

1. There seems to be a lot more separation between instruments (Easy to place musicians without trying)

2. The music sounds more open

3. The soundstage is wider and deeper.

Where do I go from here?
I absolutely want to keep the computer.

I have been trawling the internet and come across some very interesting reading about USB convertors. I have been very happy with the DTS sound I get from movies etc. I would like to improve my music quality from the PC to match a Quality RedBook CD player. (Dont we all)

I have been reading about some very high quality USB convertors with extremely low jitter outputs (I believe this may be where the optical from the computer is let down)
I thought Meridian also did this but maybe optical out from computer is so bad the G61R cannot improve the signal enough.

There has been some great reviews about the Sonicweld Diverter giving better results than $5000 CD player via computer. Also the OFF Ramp 3. Both use USB out and reclock the output to reduce jitter etc. There are also some cheaper units like the Hiface etc.

Have any of you guys used any of above or suggestions of devices you may have used that can give me the Red book sound quality I require from my Computer?


Regards Simon

optical out to a M518

If DTS is working for you then it's a good chance everything is operating "bit perfect" but it's not a guarantee (DTS can smooth over errors). Assuming things are "bit perfect" all that's left is jitter. And both the processor and speaker should get rid of any jitter upstream. You might want to verify the Marrantz is "bit perfect" by playing a DTS CD (test samples that you can burn are on WIKI).

Also keep in mind you can be blocking stuff beyond 16bit and DTS will still play just fine. You can use the DAC resolution test to see how far beyond 16bits your getting (See Wiki). You should be able to get to 19-20bits fairly easy. If not something is not right.

Also you need to verify that Meridian isn't auto sensing PC as 24bit and bypassing resolution enhancement. I have not found a good way to verify that yet. Because SPDIF is ALWAYS "24 bit" and I don't know how Meridian senses it.

You could consider Music Server which is basically a "wireless soundcard" but that locks you out of applications like J River and Winamp (which I actually enjoy using myself at work). SqueezeBox Touch (24/96) or Transporter (super low jitter and 24/96) come to mind.

Problem with 518 is your locked into word size on your source (same problem as 568). And limited to 48khz.

I assume you have read about the +3dB Tweak and are you comparing CD wired straight to 5200's with computer on G61R or anything like that?

Everytime I've dug deep into something like this, I find a logical reason for the difference. #1 is I imagined it. #2 Volume differences #3 Computer setup problem, lots of subtle things can still be wrong when you think it's right #4 one component is diddling the bits, there is only one "bit perfect". And I think jitter is marginally audible these days and with Meridian that is especially true.

You might consider getting a TASCAM US-144 MKII. Great unit to help diagnose things and can act as an alternative SPDIF sound card you can compare to. They are fairly cheap. $122 on Amazon.

George
Some very interesting points and things to try.
I need a while to take all this in.

I have just tried the DAC Resolution Test. I was able to just hear the 21 bit test (with my ear at the midrange) I could bearly hear the 15 bit test with the volume at normal litening levels. I did the test direct mode. Just one thing, only the left speaker was giving sound. Is this correct?

I will look at the +3db tweek. The Computer and CD both going into G61r.

I have looked at music servers but at present would like to see if I can just use the Computer as transport for everything.

I will take a look at the Tascam

Regards
Simon

If you're only using the PC for ripped CD playback, make sure the output from it is set to 16 bits @ 44.1KHz.

Then make sure your processor is set to 16 bits for that input.

I found that my Meridian gear does a much better job of resolution enhancement and up-sampling than my computer (Mac Mini).

You might find that your PC is forcing everything to 48KHz or 96KHz.
In my experience this non integer up-sampling kills the music like you have described.
The DTS test may still pass with the above set up.

Steve.

5imon,

There are quite noticeable differences in interfaces from computer to SPDIF. Try a M2Tech HiFace (not expensive) and be wondered, specially if you have some HR downloads.

A friend took some measurements of its SPDIF singals and compared to other adapters and some dedicated sources, and the difference on the'scope display is astonishing. But more important is how it does sound (or maybe does not!). I have already two of these!

Cheers,
Josep

M518 will do 44,48 /24bit, in processer mode( Type III)
After that M up sampling does the biz
Perhaps a better optical out from your PC might help, good cable and clean connection too.
Roger

I use Mac Mini optical to M Audio CO3, AES/EBU to M518, coax to 568, no difference in sound quality to M506 CD player via coax to the same M518.

Steve.

I do not see it mentioned in this thread, but you only get 'bitperfect' using ASIO. If you use standard Windows sound output (MM lib), the sound goes through the k-mixer, which basically ruines the sound. If your soundcard does not have an ASIO driver, you might try ASIO4ALL.

He has a g61r and there is no way to set input word size. Which is a good thing.

If he is running proper ASIO it should output same word size and sample rate as source file. ASIO4ALL is not true asio.

You raise a good point on dts to test with a 44.1 dts rip.

Josep



I have been looking at the M2tech-Hiface. I am hopeing to borrow one of these type of convertors in near future (I would like to try first as Meridian should be reclocking output from computer to lower jitter). Do you find it makes a big difference with your setup?.

Regards Simon

Steve


I did try settings in the J river output settings and Audio settings in the Volume setup (Win 7) but this appeared to make no real difference.

Regards Simon