audio over USB v. optical

**HIPPOhifi** · 02-22-2007, 09:25 PM

Originally Posted by Felix509

So Mr Hippo,(smiling as I type that) USB bandwidth?? The PCM2707 is USB1.1, will running multiple DAC units give problems(pauses in music stream, etc.) Would the Source computer need seperate USB controller cards for each unit??

Haven't been called Mr Hippo before, but it kindof has a ring to it. Good question, in the previous test with Frequency Allocator, I didn't notice any pauses over the 10min test. This link
explains a possible issue, but all you would need is two controllers for 4 bloats. If you were going to use 4 bloats I would expect you would install another controller as you would be more than likely to run out of ports.

Either way I will give 3 or 4 bloats a try over the weekend...

**HIPPOhifi** · 02-22-2007, 09:56 PM

Originally Posted by JasonWW

If this works out, maybe you could offer a discount for folks buying multiple Bloats at one time. Or maybe even a group purchase price.

I would entertain this idea. Multiple bloats 5% and a group purchase of 10+ 10%, this discount can be applied to the current special. Current special link here, I would obviously offer a larger discount if the current special wasn't on.

Originally Posted by JasonWW

Also, and I may just not be thinking here, what is the purpose of using ASIO in this particular application? Is it needed or does it just increase the sound quality?

EDIT: Ah, I believe it is a neccesary part to get this whole thing working.

Well two reasons, better quality as it skips a number of audio processing layers in you operating system and Frequency Allocator requires ASIO input with these devices.

**turbocad6** · 02-22-2007, 11:09 PM

I noticed that your not running an equalizer pluggin,

the ultimate test is going to be 4 bloats, all running as described, with each channel having at least 1/3 octave, 31 band eq..., running a DVD off the hardrive.....

what kind of CPU load is reached & on what spec machine....

this is ideally how this would be used

if this is achievable with a 60-65% load on a reasonably powerful machine, then this is an extremely practical setup & should sell, I'd want to do one in my next build

**durwood** · 02-23-2007, 06:26 AM

Do you see any issue with different clocks? Or do the multiple DACs share a clock somehow?

**RedGTiVR6** · 02-23-2007, 09:41 AM

good to know it worked!

still a little.....bloated though....lol

however, it's definately a step in the right direction!

**Ruffy** · 02-23-2007, 10:17 AM

Originally Posted by HIPPOhifi

Well two reasons, better quality as it skips a number of audio processing layers in you operating system and Frequency Allocator requires ASIO input with these devices.

True since you'd be running bit-perfect when playing a lossless compressed file and bypassing the windows audio stack would greatly increase quality.

**RedGTiVR6** · 02-23-2007, 10:32 AM

in this applicaion, if you're doing tuning on the PC, you're no longer running bit perfect...it's not needed.

**turbocad6** · 02-23-2007, 11:04 AM

bit perfect means it's identical to what's on the cd... at the 44.1k... anything that alters this stream & it's no longer bit perfect, which means exactly the same bit for bit...

volume control on the pc, or any alteration at all to the bit stream & it's no longer identical to what's on the cd, but... we still want to start with a bit perfect stream before alterations from the software..., so in the end were dealing with an altered & adjusted bit perfect stream, of course it's no longer bit perfect, but the results will still be better than if we started with an upsampled to 48k before tunning... both will no longer be bit perfect, but one is still better than the other...

**RedGTiVR6** · 02-23-2007, 11:15 AM

yeup

**JasonWW** · 02-23-2007, 06:18 PM

Just an interesting fact, but on XP and W2K even if the audio is not resampled from 44.1K to 48K it is STILL resampled from 44.1K to 44.1K through the Kmixer. This is yet another reason the SQ drops.

Originally Posted by HIPPOhifi

I would entertain this idea. Multiple bloats 5% and a group purchase of 10+ 10%, this discount can be applied to the current special. Current special link here, I would obviously offer a larger discount if the current special wasn't on.

You know, I forgot all about the special. I was thinking they where the regular price. Sorry about that.