Q&A With Mike Moffat, Schiit Audio
I read Herb Reichert's review of the Schiit Audio Mani phono stage in Stereophile where he mentioned that the famous Loesch phono preamp was inspired by one of your designs, something I didn't know about you and I'd imagine other people equate you with digital design. Can you tell us about your background in hi-fi?
I had no idea about the Loesch preamp or that it was inspired by an earlier design of mine. My background was building analog designs prior to 1982. My first manufactured product was very different for its time, where all competing designs were utilizing 12AX7 tubes with feedback equalization. My design was 6DJ8 based with passive equalization. This was in the mid 1970s. I had a lot of fun building offbeat for the time tube designs until I wavered into digital in the early 1980s. At the time, early digital sounded so vile that I was interested to see what I could do.
The Theta Digital DS Pre from 1988 was the first DSP-based outboard digital to analog converter. Can you tell us about the DS Pre?
As far as I know, it was the first outboard digital to analog converter, period. The Wadia unit was available a few months later. The Theta units took years to develop, combining a time and frequency domain proprietary filter, running in the first available DSP processors, the TMS320 series. It had high output, another analog input, and a volume control. The DSP Pro was released months later, without the quasi-preamp function.
How did Schitt Audio come about and can you talk about the name as well the general Schiit attitude?
It was named by my partner's wife, as a joke. There was endless debate over what to name it. When there was no solution to the naming dilemma, we decided to name and spell it Schiit. Jason and myself have 70 years combined experience in the audio market. We have seen fads come and go.
"Our attitude is to build the best for less, period."
There is an ever increasing youthful market and demand for high quality audio in support of computer based systems. That was our start point. Our attitude is to build the best for less, period. With the need for, and our subsequent production of stereo digital to analog converters in that market, it becomes obvious that we are headed into more mainstream, 2-channel, audio products. Since we are direct, our performance/price ratio is doubled. Our products are designed to be simple – this means no dealer intervention or installation is required, saving our users big bucks in the process.
We have no nose in the air qualities. We discourage overly serious, hand-wringing, superior attitudes. We know that no matter what we build, there will be some who will not like it. It is up to us to build products that succeed. It is none of our business what others think of us. We know what we can do and just keep doing it. We just keep doing what we have been doing for years and years. Most of the time we are right in product selection and targeting. In the few occasions we have been wrong, we move on. We are not perfect, but we have a hell of a time. Read our FAQs.
Schitt makes DACs ranging in price from $99 to $2299. What should people know about DACs and why do some cost more than others?
Our DACs below $400 and below are Delta Sigma. Audio is the red-headed stepchild of electrical engineering in general, several prestige notches below say, microwave rf or computer hardware design. Delta Sigma DAC chips are the delight of “audio” chip makers. They come complete with cookbook “how to make” data sheets and reference designs to copy. They are also cheap. We could not design a $100, or even $150 digital to analog converters without them. DS designs are so easy to make that the result is that are many of them (not all) on the market designed by digital engineering unsophisticates. The keyword is cheap and easy.
"I do not believe in making non oversampling (NOS) converters. The required NOS analog “brick wall” filter has multiple poles and is very prone to ringing and horrendous phase shift."
All of our converters at $600 and above are multibit and multirate. By multirate, we mean oversampling. I do not believe in making non oversampling (NOS) converters. The required NOS analog “brick wall” filter has multiple poles and is very prone to ringing and horrendous phase shift. Our multibit converters are also upgradable (as well as our $400 DS Bifrost) as technology becomes available. Although our policy is to make no sonic claims for any of our products, my clear preference, not only for headphone systems, but even more critically so for speaker systems is multibit. Perhaps you may agree.
Unfortunately, they are far more expensive to develop and build, particularly when proper instrumentation and weapons grade DACs are used. This is opposed to the cost constrained “audio DAC chips” marketed to the “audio” sector. (Read DS) Multibit DACs are capable of converting a literal copy of the recorded data. DS ones cannot.
Can you provide some details on the Closed-Form Digital Filter used in the Yggdrasil?
The below are the claims of the Digital Filter/Interpolator in the Yggy/MB Gungnir/MB Bifrost:
- The filter is absolutely proprietary.
- The development tools and coefficient calculator to derive the above filters are also proprietary.
- The math involved in developing the filter and calculating has a closed form solution. It is not an approximation, as all other filters I have studied. Therefore, all of the original samples are output. This could be referred to fairly as bit perfect; what comes in goes out.
- Oversimplified, however essentially correct: The filter is also time domain optimized which means the phase info in the original samples are averaged in the time domain with the filter generated interpolated samples to for corrected minimum phase shift as a function of frequency from DC to the percentage of Nyquist - in our case .985. Time domain is well defined at DC - the playback device behaves as a window fan at DC - it either blows (in phase) or sucks (out). It is our time domain optimization that gives the uncanny sonic hologram that only Thetas and MB Schiit converters do. (It also allows the filter to disappear. Has to be heard to understand.) Since lower frequency wavelengths are measured in tens of feet, placement in image gets increasingly wrong as a function of decreasing frequency in non time domain optimized recordings - these keep the listener's ability to hear the venue - not to mention the sum of all of the phase errors in the microphones, mixing boards, eq, etc on the record side. An absolute phase switch is of little to no value in a non time domain optimized, stochastic time domain replay system. It makes a huge difference with our MB units. This switch is incorporated in the Yggy.
- This is combined with a frequency domain optimization which does not otherwise affect the phase optimization. The 0.985 of Nyquist also gives us an advantage that none of the off-the shelf FIR filters (0.907) provide: frequency response out to 21.71925KHz, 43.4385KHz, 86.877KHz, and 173.754KHz bandwidth for native 1,2,4, and 8x 44.1KHz SR multiple recordings - the 48KHz table is 23.64, 47.28, 94.56, and 189.12KHz respectively for 1,2,4, and 8x. This was the portion of the filter that had the divide by zero workaround which John Lediaev worked out in 1983, to combine with #4 above AND retain the original samples.
DSD is an incompatible with prior art audio record(or mastering)/playback system. In this sense, it has much in common with Quadrophonic records, 4-track and 8-track tape players, Elcaset tape players, open reel tape players, cassette tape players, DATs, mini discs, and some others which I may have missed. These are marketed as either technically superior, (DSD) or more convenient (cassette tapes). I was never a technical fan of DSD (a further extension of DS DAC tech – further away from reproducible numbers).
"My experience of the last few dozen years or so told me that yet another scheme to convert recording studios and resell the music lover his music collection once again was almost certainly doomed to fail."
My experience of the last few dozen years or so told me that yet another scheme to convert recording studios and resell the music lover his music collection once again was almost certainly doomed to fail. Further, with DSD, the huge size of the files made it a virtual certainty it would neither be streamed by any major providers nor its music sold by the likes of Apple or Amazon, necessary to guarantee the success of the format. The problem was that I had a zillion requests to make something for the DSD format. So I caved and built the Loki, a low risk product for a niche I adjudged to be stillborn.
I was wrong in the sense that it was not stillborn, just very low survival potential. It has been helped by the fact that the many of the DS DAC chips mentioned above in question #3 have incorporated DSD as a buzzword “feature”. We actually took a flyer and built 1000 Lokis which had been (sales-wise) slowing until we recently ran out of them. We had a Loki funeral party at Schiit and will make no more DSD products – at least unless the format ever recovers from its condition of being almost on life support as well as being distributed by the majors.
There's been some controversy over the Schiit Wyrd, which is a "Audiophile USB Hub". From a technical perspective, why does the Wyrd make a difference in terms of a system's sound quality?
That is an interesting concept, particularly given Schiit's policy of making no sonic claims for any of our products. We do that not so much out of sonic agnosticism – we well know that products sound different; rather, we prefer to let our customers determine for themselves what pleases them sonically. I also strive to find measurable differences between sonic differences. I have several projects to that end in process now.
Returning to the Wyrd, it was initially designed as a fix for the very widely variable performance of USB sockets on computers in general, and PCs in particular. Since PCs come from many makers, the quality variance over a large sample of PCs varies significantly according to cost. The connector quality varies as well. What this means in the real world is that one USB socket on one computer does not equal another on different machines, nor even on the same one.
"What this means in the real world is that one USB socket on one computer does not equal another on different machines, nor even on the same one."
A significant cost for Schiit, one that becomes critical when we sell tens of thousands of $100, $150, and $400 digital to analog converters is that of customer service.
Hence the Wyrd – it was built as an inexpensive, quality USB Hub for the purpose of streaming reliability. It was the first product of its kind, and is well suited for that purpose. We are well aware of the fact that many have noted sonic differences, even though there is little in the way of consensus. That may make sense in system sample to sample variability, given the differences in source USB, and target converters. This gives rise to an exponential rise in YMMV, and makes it even more important with this product to stress we make no sonic guarantees. It is first and foremost a reliability enhancer.
What are the top five aspects of a DACs design that directly influence how it sounds?
Multibit, multibit, multibit, multibit, and finally – multibit. Multirate with a proper filter is required for best reproduction of Redbook material. To clarify, “proper” means time and frequency domain optimized.
If you could describe your design philosophy in one sentence, what would it be?
To sonically delight as many people as possible as inexpensively as possible with technologically sound products.
What can we look forward to from Schiit Audio?
I am always looking for ways to reduce the cost on Multibit design. At $600, the Bifrost MB is the lowest end of that scale. I hope to make Multibit tech more affordable as time goes on, without resorting to major cop-outs such as NOS. As I attend more and more headphone meet-ups, I see an enthusiastic group of young audiophiles who are much like I was at that age. They are very limited in their funds available, and very unlimited in their enthusiasm to listen to music on better equipment. The more we bring in, the better. This is required for a legacy, not just mine, but that of our hobby. If we collapse into a series of products which are priced above cars, our pastime is doomed. We must remember to play to our customers, not other manufacturers. We must remember not to take ourselves so seriously that we deny ourselves the fun of the hobby. I digress.
"We must remember not to take ourselves so seriously that we deny ourselves the fun of the hobby."
There is one other product that I am working on which is a new and completely different product category. It is not a D/A nor A/D converter, amplifier, DAP, nor anything resembling any product ever built in support of audio. The seeds for it were inadvertently planted when I played in a bluegrass group 50 years ago and wondered why expensive, old instruments sounded far better than newer ones. We call it “The Manhattan Project” and I have a prototype “Gadget” running which is absolutely hair raising. It operates only in the digital domain.