Here is a better way to decide: customer posts on various forums:
http://www.empiricalaudio.com/news-and-reviews/off-ramp-converter
Steve N.
Empirical Audio |
Al is correct. Each design is different. Its not just jitter either. The output driver impedance matching and voltage is critical too.
Steve N.
Empirical Audio |
Dont believe everything you read. One thing that all PCI interfaces have in common is poor sound quality. The power and ground planes inside a PC are just too noisy to achieve a low-jitter master clock. Best to get this outside the computer and on its own low-noise power supply as in Async USB. Computers are built as cheaply as possible, including the PCI infrastructure. They are barely good enough to operate, but not good enough to support a low-jitter clock. I know because I worked as a designer and design manager at Intel corp. for more than 17 years and at times in the platform group.
The right USB interface on the right power system will always beat a PCI card inside a computer, as well as 99% of CD transports.
Many more rooms at shows get awards with USB interfaces that those with PCI interfaces.
Steve N.
Empirical Audio |
Certainly listening is the best way. I offer 30-day money-back, less shipping, so the risk is minimal.
I was just commenting that one vendors review is not as good as many customer unbiased posts.
Steve N.
Empirical Audio |
I welcome such a comparison. I have not lost in a fair shootout yet.
Steve N.
Empirical Audio |
Ethernet is the best possible option. We will all migrate to it eventually. It has the same benefits as Async USB, but avoids the issues that occur in computer software, making the computer/ipad a "don't-care".
I don't expect Ethernet to improve sound quality significantly over good USB interfaces, but computer optimization will hopefully not be necessary anymore, which is a big win for audiophiles.
Steve N.
Empirical Audio |
In order to make broad conclusions about USB IMO, they must have auditioned every USB interface with every server configuration. This is highly unlikely. They can only rely on their own experience, just like the rest of us.
There are a lot of poorly conceived USB interfaces, even big names. Most of them on popular DACs are not that great. This is the reason why some people have a less than stellar experience with USB.
If you ask Antipodes, whose server is excellent, they would likely make the opposite claim, that with the RIGHT USB interface, USB is far superior to S/PDIF.
I, on the other hand have had a LOT of experience with many different high-end PCI cards, Sonos, Squeezebox2, 3, Duet, Touch, Firewire interfaces and several USB interfaces, adaptive and Async. I have designed or modded all of the above. My USB interface is 5th generation (Off-Ramp 5) and 6th is in prototype stage. I have used or modded servers including Naim, Qsonix, Soolos and Antipodes as well as modified Macs and PCs. I believe I am in a better position to determine which technology is superior. Empirical Audio has been in business for 18 years and I have been doing digital design for 38 years. Async USB driving S/PDIF or I2S can be every bit as good if not better than PCI bus driving S/PDIF, providing a good design and implementation. Driving I2S it should be better because it avoids S/PDIF conversions.
Steve N.
Empirical Audio |
To be fair (unlike cerrot), Bryston uses a Juli@t PCI card in their server with very good results, although not quite as resolving as the best USB IMO. I thought their system at RMAF was better than any other all-one-manufacturer system. They even have their own speaker now.
Steve N.
Empirical Audio |
Koestner - some USB interfaces are constantly improving, even my own. I have done at least 2 mods to the Off-Ramp and added an optional power supply in the last year. It is 5th generation, Off-Ramp 5.
The thing to realize is that an external USB converter like an Off-Ramp 5 driving your USB DAC with S/PDIF will undoubtedly beat your USB interface and probably your transport too. I have lots of customers using the Off-Ramp 5 to drive USB DACs, abandoning the built-in USB interface. 30-day money-back, less shipping.
Off-Ramp 5:
http://www.empiricalaudio.com/products/off-ramp-converter
Steve N.
Empirical Audio |
Timlub - these different Async implementations have more to do with the drivers or lack thereof and maybe support for DSD.
The jitter performance of each of these is really independent of the base chipset, assuming the designer knows what he is doing. A lot don't.
This is the reason why I don't expect the SQ of my newer XMOS implementation to be much different than my current M2Tech implementation. If anything, the galvanic isolation will make the difference. Galvanic isolation can be designed into the M2Tech implementation as well, but I didn't.
Steve N.
Empirical Audio |
Koestner - Some Linux servers have put the edits in to support M2Tech/Empirical products, others haven't. I know that Sonore and Antipodes have these mods in them. I used Antipodes at last RMAF.
If your server does not put in these edits, then you may have to wait for Off-Ramp 6, which supports Linux without custom drivers.
Steve N.
Empirical Audio |
Everyone seems to think that the DAC is more important than the master clock device (USB converter or reclocker). Not so. The jitter of the source is more important, particularly if you goal is to eliminate harshness and get more detail, better slam and imaging.
I would much rather have a less expensive DAC and a good USB converter.
Steve N. |
"Why is it that Top quality USB Converter/re clockers are not typically built into the DAC itself, or why can't it be or maybe why is it that outboard USB converters seem to always be better than an onboard unit? Power supply? "
I'm afraid that its just experience and design skills that are lacking. Most USB interfaces on DACs are either new designs by designers that have never done this before, or they are designs by third-party contractors with more interface experience, but little product experience. Product experience would allow them to select the best clocks and other components, optimize the power supplies and the ground-plane infrastructure in the DAC to achieve really low jitter using USB to I2S.
The built-in USB interface (USB to I2S) on my Overdrive DAC is now actually better than the Off-Ramp 5 with Dynamo power supply that I sell.
Totally uninteresting tracks like "Gimme Shelter" from the Stones Let it Bleed now sound fantastic, with weight, depth, slam and great tonality. I can actually understand most of the lyrics now.
Steve N.
Empirical Audio |
Mordante - I2S is not particularly helpful if the clock is still powered by the computer. The main objective is to reduce the jitter of the master clock. The best way to do this is get the Master Clock out of the computer and on its own power system/supply.
Also, S/PDIF can be superior to I2S if it is galvanically isolated from ground returns. I2S and HDMI I2S is very difficult to galvanically isolate. I have both HDMI and RJ-45 I2S outputs on my products. I was the first to put HDMI I2S on my Off-Ramp 5 USB converter.
Steve N.
Empirical Audio |
