First Steps into Computer Audio

Get the DAC out of the noisy electronic environment of the computer....definitely will make an improvement. I don't know what your budget is, but based on what you've done so far I'll hazard a guess and recommend an MHDT Labs Paradisea DAC..You can probably find a used one for under $500. Their Havana DAC is even better, I'm told, but quite a bit more expensive and more difficult to find used.

Tok2000 - I haven't seen your posts here in ages! My friend has been working with Steve on getting his PaceCar and Northstar modified DAC to work out for him. His been mightily impressed by the Pacecar in demo. Seems like beyond the budget of what the poster is talking about, but de-jitter is certainly a good idea. There's also Genesis Digital Lens, and Monarchy's solutions, which are more frequently on the used market at reasonable prices. Don't know how they might compare.

USB is for printers?! Can you elaborate on that comment? I don't know that it's as much a matter of of the computer side interface since even USB 1.1 is plenty fast to stream music, but I think the DAC side makes a more significant difference. Those solutions like Empirical's, which go straight to I2S rather than convert from S/PDIF would be the direction I'd go. Again, you'd be breaking what I only anticipate might be your budget, but another good choice might be Red Wine Audio's Isabellina DAC (USB>I2S). I heard that NOS DAC at CES recently and it sounded great! Just a stream of thoughts....

Cerrot - thanks for explaining that a bit. I did a search but could not come up with much at all. Would you point out some URL's that expand more on this as applied to DACs? As I understand it USB is much easier to implement than Firewire and certainly most offerings in audio DACs and servers use USB. The ones that implement Firewire are usually much more expensive, like the DCS gear (which wouldn't be my inclination to recommend to someone stepping up from a card in their computer). Do you know of any reasonably priced Firewire DACs? Wavelength DACs are now using an asynchronous USB technology, but they do suggest using a Firewire hard drive to store your music library on. Empirical's offerings are all USB. Those are certainly two of the more respected computer-audio offerings in the high-end. I've listened to many USB DACs that do an outstanding job, packets or not. Certainly from the standpoint of what they sound like, I cannot hear any reason to dismiss USB on face value as a DAC interface. The computer audio solutions I've tried have all sounded equally as good, if not better than the best standalone player I've listened to and owned. None have used Firewire.

However, inexpensive USB audio sucks, in my experience. If you have a good system, products like the Keces, HagUsb, and the USB input on many otherwise good DACs are complete non-starters compared to playing a CD via a transport.

I tried the HAGUSB briefly and did not like it at all. That was many years ago - Perhaps they've improved it. The USB input on the MHDT DAC was good in my system and would easily compete with many of the standalone players I've owned. I would not consider it expensive at around $600 new. The current Modwright Transporter I use (via wireless, NOT usb) without any doubt at all exceeds any transport I've used via wireless connection to my music library two floors below in my basement. Using a transport into the DAC of the Modwright Transporter it is marginally better. Disclaimer: Modwright is one of my clients. The Benchmark USB DAC, though I ultimately did not like it for the same reasons I didn't like it via a transport, did not give up much via USB. I've heard the same USB Benchmark in a few rooms at both RMAF, CES and THE Show sounding quite good (contrary to my own experiments with it). Red Wine Audio's Isabellina DAC was sounding great via USB. Maybe I'm misinterpreting your intent, but it seems like it's a broad and sweeping statement you've made for having studied for "several months". Does that mean you've tried out many different USB DACs - if so, which ones? I guess I'd say my impressions are different (obviously) and I've been using computer audio for several years rather than months (and did not always favor it). I would agree that some of the cheap USB devices have the potential to be poor performers as does any cheaply built/designed component. No surprises there. I think the potential of PC Audio in general could easily exceed the performance of a CD transport. Check out the recent article on the high-rez formats and the Berkley Alpha DAC - I think in TAS...maybe January...or was it Decemeber? I'd suggest you give it a better chance as there is great potential there.

So each of those four DACs you've tried left you with a strong preference for a standalone player, and not liking USB DACs in general (I'm not sure I'm interpreting you correctly in that - forgive me if not)? Of those you noted I've only heard the Benchmark, which, as I mentioned, I did not like (found the highs ever strident - but same via a transport), so I could understand your not liking it. I've also heard the Bel Canto, though not in my system. The Bel Canto sounded great in the TAD room at RMAF '07 fwiw and to my ears, and again at CES recently in the Bel Canto room. I've not heard the other two. You sure seem to have liked the Ultra-fi iRoc USB DAC. From your ad:

Honestly, I would call it the most musical component I can remember owning -- by which I mean that it extracts the musical line in a compelling fashion from everything you play.

If you're ever up in the Seattle area you'd be most welcome to come over and hear the TP in my modest system. Ping me through A'gon for my contact info.

I keep hearing folks allude to fire wire, & I2S. i DON'T SEE MUCH BY WAY OF AFFORDABLE PATHS THERE THOUGH. i2s, ESPECIALLY. a $1,000 for the gizmo needed to get the info to a I2S DAC? Then there's the I2S DAC costs. how much is a decent one of those going for lately?

Blindjim - if you're happy with your current DAC/rig there's no reason to change. But to answer your question, certainly at the $2k cost of your BC there are I2S options. I think Red Wine's Isabellina is $2500. Northstar, Perpetual Technology and Audio Alchemy all have I2S DACs. Empirical Audio also modifies some DACs, like the Benchmark, for I2S input. You can read an interesting article by Steve Nugent of Empirical which contains much information on USB and I2S in Positive Feedback, here. Like you, I've had pretty good results with USB. I've only seen very expensive firewire options out there. I've yet to read anyone else opine that Firewire is a superior interface for PC audio purposes, and am still awaiting some links from Cerrot to support that statement.

All I said is that cheap USB sucks, but obviously mileage varies. The iRoc is not cheap USB. And I may need to back off my earlier comments a bit after last night, when I was very impressed with the USB input on the Bryston DAC.

Sorry I didn't get your gist - I thought you were making a broader critical statement than that. At the $550 you sold the iRoc for it seems pretty affordable to me, but I guess that's all relative. Cool beans on the Bryston results. Their CD player got a good review in the recent TAS fwiw.

Cerrot - I guess I'm missing your logic here. Though I can understand that firewire delivers more information, faster than USB 1.1 (I'm pretty sure most USB DACs are using the older version), if it's delivering the info to a buffer where it is then passed on and reclocked by the DAC, how is delivering it any faster going to make the music sound better? Perhaps I'm missing something, and if so, somebody 'splain it to me. If a grocery store needs a steady supply of three cases of Spam every day it won't matter much if it's delivered every morning by a man in a delivery truck or two race car drivers in a Ferarri - the Spam still arrives each morning in time to be sold. The Ferarri may be a better vehicle to get the Spam to the store faster, but what's the point if the truck can get the same Spam there every morning as well? If firewire is a better interface for DACs then why are some of the best PC DACs using USB?I'd be interested to hear from someone like Steve Nugent who actually designs this stuff and makes that decision.

Thanks for the link, Drubin...that's an interesting read. Also, Ckorody for the computer interface history.

Thanks - I didn't even notice that. EXCELLENT information from various perspectives. For Cerrot, here is the take from the initial question about interfaces posed to Steve Nugent of Empirical. This also goes directly to the question of USB vs Firewire:

The only interface of those listed that can have Async protocol, or handshake with flow-control is USB. Firewire does not support it and neither does AES/EBU or S/PDIF, coax or Toslink. Async protocol allows the master clock to be located at the designation device, either a converter, reclocker or the DAC itself, which is the optimum scenario. This establishes the master clock near the D/A conversion and then controls the source rate using a flow-control protocol.

However many USB and all Firewire interfaces do not use flow-control. The jitter characteristics with these is only as good as the circuits/chips that track the incoming stream from the computer. The master clock is established at the source, which is the computer, and then this must be maintained by all circuits up to the D/A conversion. The jitter from the computer must be dealt with by using PLL-type devices (Phase-Locked-Loop). These track the incoming datastream and synchronize to it, as the same time using filtering and other clever tricks to reduce the jitter of the original stream. Fortunately, there are a few very good chips available that deal with jitter very effectively, namely the DiceII chip for Firewire and the TAS1020 for USB. Even though these do not establish the master clock for the system and instead track the computer datastream clock, their jitter rejection is excellent. Current support for samples rates is: USB - 24/96, Firewire - 24/192 and S/PDIF - 24/192. Look for this to change in 2009.

Of the interfaces listed, an important one was omitted, and that is networked, otherwise known as LAN, Ethernet or Wi-Fi wireless network. The protocol of this network has inherent in it the flow-control and retry mechanisms that enable the optimum audio streaming scenario, as well as having the advantage of avoiding altogether the sometimes troublesome audio software stack of the computer OS. Using networked devices, either wired or wireless can be no different than sending data to a printer. The only concern is getting the data to the device intact. There is no timing information sent or implied. The data is not contiguously streamed at real-time speed as with USB, Firewire or S/PDIF interfaces. It is packetized and sent periodically in high-speed bursts over the network, whenever the network has an "opening". These packets are then collected in a buffer memory at the destination device where they can be clocked out to the D/A using a local low-jitter master clock. The fact that networked data flow incorporates flow-control and retry, and bypasses the computer audio stack makes it the superior method. The only disadvantage is that the player that interfaces to the network is currently a custom player, such as Squeezecenter or Sonos. Hopefully, in the future Microsoft and/or Apple will create more generic player software to drive a networked interface so that more player options will be available. As for bandwidth, networked interfaces can not only support the highest audio sample-rates, such as 24/192, but it can support multiple channels of this, allowing for multiple channel playback for software generated speaker crossover and even movie surround-sound.

The index of all of the interviews is here

Thanks again for pointing that out, Drubin.