winders
Headphoneus Supremus
2017 Chapter 9: Skipping a Generation
A long, long time ago (seemingly back in the Paleolithic era), I once asked Dave, "Has anyone done anything like Theta's TLC (a SPDIF reclocker) for USB?" Which led, very shortly, to Dave bringing in a small board that would become the Wyrd.
As you probably know, since then, USB just hasn't been the same.
Our little decrapifier set off an audio feeding frenzy which is still spooling up to this day. Yeah, I know, there were other devices to clean up USB power before Wyrd, but the commonly accepted format of the decrapifier—clean power and repeated packets—started with Wyrd.
In a sane world, Wyrd would have been the end. It was a product with a really exotic, low-noise, linear power supply, quality crystal oscillators for repeating the USB packets, and a stout amount of current available to run power-hungry devices. It solved the problem we were trying to solve—the problem of drop-outs and noise from underpowered and/or noisy USB ports, and it did it very well.
Aside: Ironically, the problem that we created Wyrd to solve (crappy USB ports) is much less of a problem these days. It seems that the latest OSes and motherboard firmware (mostly) realize that if a device asks for 500mA, it really wants 500mA. Underpowered USB hardware also seems to be on the wane. The usual experience these days, on Mac or PC, is “plug and go,” provided you’re running the latest Windows or Mac OS.
Now, Wyrd was a device that we also claimed no overt sonic benefits for. This was our way of being a responsible manufacturer, as there is really no mechanism that could result in better sonics. However, some (including Dave and myself) thought things sounded better when Wyrd was in the loop.
But we didn’t go there. We said, "Use this if you have noise or problems with connectivity." And in a sane world, that would be the end of it.
But audio is not a sane world.
Which meant, after Wyrd, there were any number of manufacturers ready to step up to the plate, to make devices that cost more, for which they claimed different variations of the old "angels singing in your ears" night-and-day sonic improvement. Ironically, many of these more-expensive devices actually used compromises such as switching power supplies...which led to a whole new sub-market for linear supplies at even higher cost to improve these more-expensive devices, which caused a lot of other companies to take notice and introduce their own filters, or next-generation decrapifiers based on not-necessary-for-audio USB standards, or incorporating various tricks to claim "galvanic isolation," an adjectiveoid that has no real definition (more on this later).
Mike and Dave thought the proliferation of USB devices was pretty humorous.
"This one sells for twice what a Wyrd does," Dave said. "And it has a switching supply!"
"How about 3X, but USB 3 on deck?"
"Or what about something that does galvanic isolation, but costs 6x more than Wyrd?"
"Oh, this is killing me, they say it makes a bigger difference than the DAC! Forget Yggy, get a Modi and add this thing to it!"
And that's how it went for a long time, with me asking from time to time if there was any merit in trying to isolate the Wyrd from the PC more effectively, or if there was any merit in USB3, or if there were any tweaks we could make to Wyrd to make it better. Mike and Dave tolerated my questions like two brilliant uncles given the task of babysitting the slow cousin for the day.
(And yet, from time to time, they'd smirk and look meaningfully at each other, which is Mike and Dave code-speak for "yeah, keep your pants on, we have the red phone already ringing.")
But, all of the above decrapifier-proliferation had an effect. Which is why it's not unusual for someone using USB from their source to say, "and I use a Pflugelmeister Jitter Destroyer, coupled via a Gold-Plated Yak Hair MultiStranda Cable to a USBPolisher3.0X, then into a PrimeAlignSpaceAndTime Filter, followed by two Wyrds, in series, connected with a custom 3.776" long Tuned USB Optimizing Cable, to a DACWart USB Perfector, in order to get optimal sonics."
Let me be perfectly frank. In my opinion, the above is absolute lunacy.
Yes, I know, I've said I don't care if you get your sonic jollies by taping $100 bills to your head. But if you're talking many hundreds, or even thousands of dollars of USB gewgaws—especially when connecting, to, say, a Modi Multibit (don't laugh, people have done just that)—there's something seriously wrong with this situation.
So, yeah. Blame us. We started it all. But forgive us, too. Because we didn't know what a monster we'd create. We figured that by doing the best device possible with the technology of the time, using a linear supply, and selling it for less than any other decrapifier, that there wouldn't be much room for competition.
But we didn't count on the Big Crazy of audio.
A sad situation? Perhaps. But that ends today. Because, yeah, Mike and Dave's meaningful looks meant something. Because, yeah, they already had everything under control, mapping the next revolution in USB connectivity.
And so, as of now, you can throw away your perfecters and hyperstreamliners and cleaners and recombobulators, and, yes, even that gold-plated yak hair USB cable. Because, as of today, USB is, well, solved.
Welcome to Gen 5. And Eitr.
Getting to the Solution
“Gen 5? Eitr? What the heck are those? You’re on Gen 2 or 3 USB, right? And what’s an Eitr? Is it pronounced ‘eater?’ It probably is, we know how you think!”
Okay. Yeah. So shoot us.
Let’s step back a bit. Gen 2 has been the go-to USB implementation for all of our upgradable DACs, with the exception of Yggdrasil, which got Gen 3. Gen 3 used the different CM6632 USB receiver chip (as compared to the CM6631A, which we use everywhere else.)
And that’s the way it’s been for a long, long time. Gen 2 and Gen 3, were, in general, very good implementations. Yes, sometimes some systems had problems recognizing them, or staying connected, or whatever, but show me a USB receiver that doesn’t have those problems and we’ll gladly use it.
Aside: No, not really. Don’t bother, we’ve tested all of them. They all have glitches. Remember this interface was developed to replace the serial port, an ancient standard that sent data at rates of kilobits per second. USB is a general-purpose interface that has been built on and on and on, and it has its oddities. Hell, I have an external USB keyboard that isn’t recognized by my Microsoft Surface Pro until I plug it in and unplug it from the hub I’m using, literally every single time I bring the Surface Pro home to do some work. Read that again and think about it. That’s a friggin keyboard, guys.
Gen 2 and 3 had two problems, though:
The fact that Gen 2 and 3 required power to run caused us quite a few headaches in the days when manufacturers were being stingy with USB power. However, per the first Aside, we don’t see so many problems these days, so it seems like that era is ending. Good!
- They required power from the computer to run. This was a decision we made so that we would share as little power supply noise between the computer and DAC as possible.
- They did not have any kind of isolation from the computer. This kind of negated the benefit of (1), because the “dirty” computer ground was connected directly to the DAC.
The fact that Gen 2 and 3 shared grounds sometimes caused noise, when used with computers that had huge amounts of ground noise, or that had a ground loop (hint: if you’re having problems with noise from a USB connection, look for a ground loop first.)
“So, why didn’t you make the USB board self-powered and isolated from the start?” you ask. “Are you holding back? Incompetent? Or just horrible teases?”
Well, it all comes down to the difficulty of isolation. Or, in buzzword-speak, “galvanic isolation,” which is the term commonly used to describe a USB interface that doesn’t share power or grounds with the computer source. Unfortunately, the term “galvanic isolation” is in itself meaningless.
Let me quote the dictionary definition:
gal·van·ic (ɡalˈvanik/)
adjective
1. relating to or involving electric currents produced by chemical action.
2. sudden and dramatic. "hurry with awkward galvanic strides"
Electrical currents produced by chemical action? Yeah, uh, hopefully not. Because you don’t want to see what reactive chemicals will do to electrical contacts. Sudden and dramatic? Well, again, hopefully not (I think of fire and smoke when I think “sudden and dramatic” when coupled with electronics.)
A more useful, but more verbose, phrase would be: electrostatically and electromagnetically isolated.
As in, the interface is isolated from both electrical charges (the kind that makes your cat’s hair stand on end) and from electrical currents (the kind that charges your phone or powers your Gen 2 USB interface.)
Now, the reason we didn’t pursue this kind of isolation on Gen 2 was simple: there weren’t many good options for it. The common isolators used for USB 1.1 speeds did not work with the Gen 2’s USB 2.0 speeds, so there was no “easy” solution.
With the “easy” (USB-side) isolation not an option, that left us with the “hard way,” which would be to use optocouplers on the I2S bus after the USB interface. Optocouplers are, to put it mildly, pretty crap. Although they isolate the signal electromagnetically and electrostatically, they’re prone to jitter. This is particularly painful when it comes to the high-speed master clock.
However, when we started working on the next-gen USB interface, we tried optocouplers to start. We could simply reclock after the opto, we figured, with a high-quality local clock.
In short, bzzzt. No prize for you.
No matter what we did, the optos didn’t perform at the level we wanted. What we needed was another way to get electrostatic and electromagnetic isolation, but without the use of optocouplers. The problem, of course, was we needed something that performed at extremely high speed, for critical data…and it needed to also be somewhat common and affordable, so our new USB interface wouldn’t balloon in price.
Luckily, there’s a common interface that is actually specified with electromagnetic and electrostatic isolation built in (unlike USB).
Ethernet.
Yep. Gigabit Ethernet uses transformers to couple its extremely high-speed signals, and provide the isolation it needs.
“Transformers?” you might be saying. “Aren’t those big? And slow? And, well, kinda outdated?”
Big? No. They go in your laptop, if it still has a physical Ethernet connection. Slow? Nope, they work at GigE and above speeds (far higher than USB). Outdated? Nope, you’re channeling tube audio output transformers or something. The fact is that magnetic components (transformers and inductors) are very important in modern electronics design, both analog and digital, Class A and Class D.
So, we put together a prototype using transformer isolation. This one was like the opto prototypes in that it had:
Except, of course, the isolation was done by transformer, rather than optoisolator.
- Complete isolation of the USB power supplies (self-powered USB interface, requires no power from the computer.)
- Complete isolation of the USB ground (grounds are not shared)
- A total re-work of the USB interface, based on the CM6631A
- High precision local re-clocking after isolation based on crystal oscillators running at two separate clock multiples for 44.1kHz and 48kHz-based sampling rates.
The result?
It was, by far, the best USB interface we’d heard. (And yeah, before you start dragging out your “have you heard the latest XYZ, yes, we have…that’s our job. We try all the interfaces. And the problem is, we have yet to find something better than what we’re using.)
And, as far as I know, it’s the only USB interface using transformer isolation. When everyone else sees how good the transformers perform, they’ll probably start showing up everywhere else (just like Wyrd).
Even Mike admitted that it sounded good. Yes. Mike Moffat. Ask him yourself, if you see us at a show or at the Schiitr. It’s a very, very good USB interface.
In fact, it’s so good, that’s why we’re skipping Gen 4 entirely. Hence, “Gen 5” USB.
Gen 5 is now the standard USB interface shipping with all of our upgradable DACs—and, of course, it’s available as an upgrade for all of the Bifrosts, Gungnirs, and Yggys that are already out in the world.
Aside: sorry, DACs need to come back to the mother ship (or to an authorized distributor) for Gen V install. At least for now. We’ll see how it goes and then consider opening up the option for electronics professionals to self-install.
Price for all of this?
The same as the old USB interface. Our DAC prices don’t change. Or, if you have one of our DACs already, it’s $150 for us to install the Gen 5 board.
But Wait, There’s More!
“So what the heck is this Eitr thing? You snuck that one in, but you haven’t said anything about it.”
Eitr is, to put it simply, the way to get Gen 5 technology for any DAC. Or, well, any DAC that has a SPDIF coaxial input, anyway. Eitr is a Gen 5-based USB to SPDIF converter.
“Wait a sec, if I have Gen 5, I don’t need Eitr?”
Right. Probably not. But if you have a non-Schiit DAC, or a Schiit DAC that isn’t upgradable, or if you don’t feel like sending your Schiit DAC in for upgrade right now, or if you really, really want to have as little USB as possible in your chain, there’s Eitr. Plug Eitr into your computer via USB, then plug Eitr’s coaxial SPDIF output into your DAC. Done. Eitr’s coaxial output is even isolated itself with its own transformer! It’s got, like, even more isolation on your isolation.
(Seriously, though, Eitr is a great USB-SPDIF converter, with the same kind of attention to detail you’d expect from us, from the linear, low-noise power supply to the latest SPDIF formatting chip with high-precision local crystal oscillators for both clock multiples, to transformer-coupled output.)
Price for Eitr? $179.
USB, Solved.
So now you know why we were so crazy for so long at the start of this year. It’s not like we could introduce Gen 5 without Eitr, because lots of people would be irritated if we offered the Eitr option after they’d gone through the process of sending their DAC in for Gen 5. We couldn’t do Eitr without Gen 5, because why would be introduce this new technology in a standalone box and ignore our DACs.
And, to make things even more complicated, there are actually two Gen 5 boards (one for Yggdrasil, which does not need a master clock output—there will never be a delta-sigma Yggy—and one for Gungnir and Bifrost, which may be delta-sigma and therefore will need a master clock output.
So, before we announced, we needed:
And that was on top of all the development, testing, and qualification across the line of DACs. This is a huge, seismic change in our USB connectivity, and it touches five different flavors of DAC that we sell, as well as creates a new upgrade and an entirely new product (the Eitr.) It took a lot of coordination for things to come together, and it will take more coordination to make sure both the shipments of new DACs, and the upgrades, continue to happen smoothly.
- Both Gen 5 boards in stock
- DACs with Gen 5 boards ready to ship
- Eitrs in stock (which meant metal, boards, assembly, manual, packaging, etc.
- Description for the Gen 5 for the DAC pages
- Description for the Gen 5 upgrade
- Description for Eitr
- Press release
- Photos
But, in the end, we believe it’s worth it. It’s a much, much better interface. It provides the isolation that many customers are looking for, with performance that we don’t believe anyone else can match. And it does it for the same price as the old USB interface.
Skeptical? Try Gen 5 for yourself.
Just plug in any USB cable to our new Gen 5 USB interface. There’s no need for external power supplies, special wacky cables, strings of decrapifiers and isolators. No interface nervosa. Sit back, relax, and see what you think.
I think you’ll agree. Gen 5 is USB, solved.
Excellent job, Jason! No more decrapifiing nightmares!!
Congrats Jason and team!
