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Product Development Story: Steinberg UR Series

Exploring the development concept of the audio interfaces and the secret behind their worldwide popularity

The Steinberg UR series is considered by many to be the benchmark USB audio interface range. The UR interfaces are among the world’s top sellers in their respective product group, each a highly cost effective audio interface supporting 24-bit/192 kHz with the high-quality D-PRE mic preamp and built-in DSP mixer/effects in the form of the “dspMixFx” application. The UR series lineup now consists of six models including the recently released UR242 featuring 4 analog inputs and 2 outputs. ICON has decided to interview the developers to explore the design concepts of the UR series and the secrets behind its popularity. Three members from Yamaha’s PA Development Department responded to our interview request: Takahiro Akabane (product planning), Ryohei Koga (hardware design), and Masato Esashi (software design). We asked what key areas they focused on while designing the UR series.

Development concept of the Steinberg UR series

What was the concept behind the development of the Steinberg UR series?

Akabane: The UR series of audio interfaces was developed on the basis of three main concepts. The first concept was reliability. The audio interface is not a supporting part when it comes to the production environment centered on the DAW, but rather an important tool that makes up the core of the system along with the computer. While work is in progress, the unit remains turned on continuously. If this vital tool is unreliable, the creator cannot concentrate on their music composition. Therefore, we were determined to develop a reliable audio interface.

The second concept was superb sound quality. It is now possible to process sound as much as one likes on a computer, so we made sure that sound could be recorded and played back transparently without any added coloring. Our goal was to create an audio interface that is faithful to the original sound and that could record the true essence of vocals and instruments.

The third concept was affordable price. High performance at a high price is nothing extraordinary. We wanted to make a high performance product at an affordable price. If you are not particular about performance or features, cutting prices is not so difficult. But such products will not win customers and will quickly die away. Therefore, we made sure we retained crucial specifications and features of the audio interface that customers would expect, such as 192 kHz sampling and built-in DSP and went on to achieve this at an affordable price.

In a nutshell, it’s all about reliable and affordable audio interfaces with high-quality sound. This was the UR series development concept, not eccentric but simple and robust. 

The UR series is a range of USB audio interfaces. There was another previous product called the MR series with a FireWire connection. Is the concept behind the UR series different from the MR series?

Akabane: No, the concept itself has not changed since the MR series. The key difference between the MR series and the UR series is that the FireWire connection has been changed to a USB connection. But in the MR series, we focused on selling the DSP feature too much that only that part received attention. We failed to convey the reliability and sound quality aspects of the product to the customers. Moreover, even though the MR series was a general-purpose audio interface, we did not emphasize this fact, and therefore many thought that it was a dedicated interface for Cubase. Learning from these mistakes, we decided to advertise the UR series as a reliable, high-quality sound audio interface that would be compatible with any DAW, not just with Steinberg products.

The UR series is being sold as a Steinberg brand. Is the development all done by Yamaha?

Akabane: We work with Steinberg in the product planning, software development, and final product testing. We are totally in charge of the hardware design, development, and manufacturing.

Could you tell us about the UR series product lineup?

Akabane: The UR824 and UR28M released in 2011 were the first two products of the series. The UR824 is a 1U rack type product. It has 8 analog I/O channels and 16 ADAT optical I/O channels. So in total, it is an audio interface with 24 I/O channels. The AD/DA converter supports 24-bit/192 kHz. There are eight high-quality D-PRE mic preamps, a pivotal feature of the UR series. And the DSP functions we call dspMixFx allows monitoring and application of effects with near zero latency.

On the other hand, the UR28M is a desktop type audio interface. It has 4 analog input channels, 6 analog output channels, and 2 S/PDIF digital I/O channels. It has 2 D-PRE mic preamps. The major feature of the UR28M is the versatile monitor control function that associates with controls such as volume, mute, mono mix, and dimmer. The UR28M can be hooked up to three sets of speakers and used like a standalone monitor controller.

It appears that the UR22’s release got everyone to notice the UR series.

Akabane: That is true. The UR22 released in February 2013 is a compact, USB-powered audio interface with 2 analog I/O channels and 2 D-PRE mic preamps. The first two products, UR824 and UR28M, were also well-received, but the UR22 took off immediately after its release and is still selling all over the world.

And last year, we released the UR44, a slightly larger version of the UR22, with 4 analog inputs, 6 analog outputs, and 4 D-PRE mic preamps. It is a product that was developed for those who want a compact audio interface but feel that the UR22 is a bit too small. It also has the dspMixFx DSP function, which is unavailable on the UR22.

And the UR12, which was also released last year, is a stripped down version of the UR22 with 2 analog I/O channels and a single D-PRE mic preamp. Recently there has been a growing number of people who just record vocals and guitars. The UR12 was developed to meet the needs of such users. It also has a loopback function that can be used as an Internet distribution interface.

And now the sixth member to the UR series, the UR242 was released. Could you tell us about this product?

Akabane: Listening to the customers, we found that many of them only need 2 outputs but want 4 inputs. The UR242 was developed to meet this need. It has 4 analog inputs, two of which have the D-PRE mic preamps and 2 analog outputs. It’s a product that sits right between the UR22 and UR44. The UR242 is not USB-powered like the UR22, but it has the dspMixFx DSP function and can be used with an iPad. Another feature that I would like to mention is the -26 dB PAD function. This allows high-sensitivity mics to be connected. The PAD function is not available on the UR44, so some users may choose the UR242 for this feature. Users who need to record four mics or need multiple outputs for live performance or other applications can use the UR44 while those who only need two mics but want to use high sensitivity mics can use the UR242.

So you are saying that the specifications of each product are slightly different, not just the number of inputs and outputs.

Akabane: That’s right. The mic preamps are D-PRE on all models. In terms of the I/O specifications, only the UR28M is 24-bit/96 kHz. All the others are 24-bit/192 kHz. The dspMixFx DSP function is available on models other than the bus-powered UR12 and UR22. And, iPad connection and loopback function are available on all models except the UR22. What makes the UR22 attractive is the two D-PRE mic preamps, MIDI I/O, and bus-powered operation. I think it is also extremely cost effective.

Extraordinary reliability assured by Yamaha’s proprietary USB controller and high-performance driver perfected by a dedicated team

I understand that the concepts behind the UR series are reliable operation, high-quality sound, and excellent cost performance. First, please tell us about the reliability concept. What kind of ingenuity went into the UR series to achieve reliable operation?

Akabane: To reliably run the audio interface, it’s essential to have perfect hardware (namely the USB controller) and software (namely the driver) is essential.

First, for the USB controller, the UR series uses a proprietary Yamaha chip. Most audio interface manufacturers use general purpose USB controllers, but using a chip made by another manufacturer limits the complete understanding of the internal structure, and therefore there is only so much one can do to tune it for reliable operation. In addition, being able to procure the chips cheaply is good, but because we manufacture mass amounts of products, using a chip by another manufacturer concerns us from a supply chain perspective. Taking these points into account, we concluded that we would need to develop the USB controller ourselves even if it would be somewhat challenging. Out of this came Yamaha’s own chip called SSP2, which contains a USB controller, DSP, and a CPU for controlling the entire chip.

And, for driver development, dedicated teams were set up for Mac and Windows. Finally, both Yamaha and Steinberg perform thorough operation tests. As such, the driver performance is continuously improving, and now we are confident that we are second to none when it comes to reliability.

A hardware that we can fully understand the inner workings of, excellent software made by dedicated development teams, and strong cooperation with Steinberg, the originator of the ASIO driver standard. These three elements are what make the UR series so reliable.

Was the SSP2 chip developed specifically for the UR series?

Akabane: Yes. The previous MR series also used an original chip, but it was specialized for DSP. A general purpose chip was used for the FireWire controller. What sets the SSP2 apart is that it not only has a DSP for running the dspMixFx, but also a USB controller and a CPU. The SSP2 was developed for the UR series, but being such a remarkable chip, it is now used in Yamaha’s audio visual products and the THR guitar amp series.

It’s amazing that dedicated teams were set up for Mac and Windows to develop the drivers.

Akabane: The driver is an extremely important factor that governs the reliability of the audio interface. Even if the hardware performance is good, without a high-quality driver the audio interface can never be a great product.

 For example, I think everybody wants to set a small ASIO driver buffer size. However, when this is done, even when the CPU still has leeway, click noises may be heard. This is because the various arrangements in the OS layer get in the way. But, we went ahead and tuned this area to optimize not just the ASIO buffer but also the other related parts. This has made it possible to maintain reliability up to the maximum CPU load even when a small buffer size is selected. This scheme is also effective when a large buffer size is specified. It works to further lighten the CPU load.

Koga: I’ve seen reviews at retail stores that state that the UR series works fine even when the buffer size is set small. This is because there is a good reason. Actually, the UR series works diligently to hold through even when a small buffer size is set on a not-so-fast computer (laugh).

When we interviewed SUI (a Japanese composer/arranger/sound creator) who uses the UR28M, he also said that the UR series holds through even when a lot of load is placed on it.

Akabane: In addition, because Steinberg is the originator of the ASIO standard, it is a big advantage that we can share information with them. For example, a new driver level technology called ASIO Guard was incorporated in Cubase 7. When this occurred, we were able to quickly adjust the driver so that it would run reliably under this new format. I believe this is the great advantage of joint development. “The ability for the UR series to hold through” that we mentioned earlier has also been reinforced further with this adjustment.

High-quality mic preamp “D-PRE”: In pursuit of “sound expression” not just limited to the faithful reproduction of original sound

Next, we would like to hear about the second concept: sound quality. What led up to the development of the D-PRE mic preamp in the first place?

Koga: Yamaha develops its products based on a policy that focuses on the faithful reproduction of original sound. We thought that a music production tool such as the audio interface should have a mic preamp that reproduces the true essence of songs and musical instruments and the detailed expression of performers. This was the starting point. We developed a product based on this policy, which ultimately became the “D-PRE”.

D-PRE was first employed in a music production digital mixer called n12/n8 that had a FireWire interface. Then, it was adopted in the UR series. Because this preamp was designed to be used in music production applications, we were already thinking about employing it in the next-generation audio interface even in its development stage.

Yamaha also develops professional audio equipment. Is the sound quality of D-PRE different from the mic preamps used in those products?

Koga: The policy “faithful reproduction of original sound” is the same. With “D-PRE”, it could be said that we tried to reach as far as we could in faithfully capturing the detailed expressions of voices and instruments. When we say that we developed a new mic preamp for music production tools, people may misinterpret this as having some particular sound characteristic. But the truth is it is exactly the opposite. Going forward into the “faithful reproduction of original sound” ethos is what D-PRE is all about.

Akabane: We hear of reviews stating that the D-PRE sound is rich or thick, but it does not increase or decrease the gain of any particular bandwidth. Because the recorded sound is raw and has presence, the localization and polarity are accurate, and the response is flat from top to bottom; the expression inherent in the original sound is preserved. As a result, we believe people who listen to it describe the sound as rich or thick.

Is the circuit completely different from the mic preamps used in professional audio products?

Akabane: The development teams are different, but they are both in the same development department, so information about circuit design is being shared between them. Therefore, D-PRE and the other circuitry used in the UR series are packed with long years of Yamaha’s know-how.

Could you give us a little more detail on the D-PRE?

Koga: D-PRE uses a circuit called inverted Darlington. The name inverted Darlington comes from Dr. Sidney Darlington who designed a circuit technique called Darlington connection. In a typical mic preamp circuit, each channel is designed with two transistors, but in an inverted Darlington circuit, four transistors are used to suppress distortion at the input stage to the utmost limit. We based D-PRE on the inverted Darlington circuit, carefully selecting the transistors to use, and thoroughly tuning the peripheral circuitry to achieve sound that is faithful to the original sound.

Akabane: The “D” in D-PRE comes from inverted Darlington.

What other sound quality aspects besides D-PRE did you give a lot of thought to?

Koga: Another element that is as important as the mic preamp in the audio interface is the monitor circuit that includes the headphone amp. For the monitor circuit, like the mic preamp, we aimed for sound that is faithful to the original sound. So we didn’t do any tuning that would just make it sound good. The monitor circuit was designed so that you could monitor the pure sound coming through the DA converter.

For the headphone amp, the output is different between bus-powered models and models that require an external power supply, but we made sure that the volume level would be higher than those of products made by other companies. We often hear that the output from the headphone amp is not enough when the audio interface is used in a live performance.

The D-PRE does seem to be extremely popular. When we interviewed agraph (a Japanese musical artist), he said, “I don’t need the audio interface part; could they sell me just the ‘D-PRE’?”

Akabane: Hahaha. That’s funny. We don’t have any plans currently to sell D-PRE by itself, but it is pleasing to know that professionals like it. People who enjoy it and use it all the time have commented that the granularity of sound is clear and that tone can be captured as-is.

What other sound quality aspects besides D-PRE did you give a lot of thought to?

Koga: Another element that is as important as the mic preamp in the audio interface is the monitor circuit that includes the headphone amp. For the monitor circuit, like the mic preamp, we aimed for sound that is faithful to the original sound. So we didn’t do any tuning that would just make it sound good. The monitor circuit was designed so that you could monitor the pure sound coming through the DA converter.

For the headphone amp, the output is different between bus-powered models and models that require an external power supply, but we made sure that the volume level would be higher than those of products made by other companies. We often hear that the output from the headphone amp is not enough when the audio interface is used in a live performance.

How about the AD/DA converter?

Koga: The AD/DA converter is an important component that affects the sound quality, so we obviously put a lot of thought into it. Since the audio interface chassis is small, we also need to make the circuitry and power supply mounted in it small. This constraint forbids us from simply transferring the AD/DA converter circuit used in professional audio products, so we designed an entirely new converter for the audio interface. Here again, we followed the policy of faithfully reproducing the original sound.

Also, bus-powered products are indeed convenient, but because the power is supplied from the computer, we need to pay attention to the noise problem. Therefore, on the UR22 and UR12, a lot of thought went into suppressing the noise so that the power supplied from the computer would not adversely affect the internal circuitry.

The “dspMixFx” DSP mixer/effects supporting the latest music production workflow

Could you tell us about these features?

Esashi: We investigated the features that users would expect in an audio interface, and all of them have been covered. Such features include direct monitoring, mixing and effects using DSP, and a loopback function for Internet distribution. We made sure to include features that users would expect and excluded those that would rarely be used.

We hear from users that the dspMixFx DSP function is extremely well designed.

Esashi: That is true. We are confident that as a DSP for an audio interface, it is close to perfect. For example, it is possible to apply effects only to the monitored sound and record the source sound dry. An actual example would be, when recording a guitar, applying an amp simulator to the monitored sound but recording the raw sound. Even for guitarists that are greatly bothered by latency, this method allows latency-free recording and limitless post modification using plug-ins.

When we hear stories from customers, we find that it is becoming common for bits and pieces of music to be recorded constantly while music is being created. Composition and recording are being performed simultaneously. However, if bits and pieces are recorded with a fixed tone at the outset and the user wants to change the tone later due to rearrangement, the bits and pieces would need to be rerecorded. By applying effects only to the monitored sound, the recorded sound can be changed later as much as the user wants, and this fits nicely with the current trends in workflow.

Akabane: Another characteristic of the UR series is the seamless integrity with Cubase/Nuendo.

Esashi: The DSP functions of the UR series can be controlled seamlessly from the Cubase/Nuendo MixConsole. Also, the Cubase/Nuendo monitor bus and the UR series monitor bus have the exact same internal construction. As a result, even if you think you are controlling the Cubase software mixer, you may actually be controlling the UR series’ DSP. Therefore, Cubase/Nuendo users can use the UR series’ DSP functions without being conscious of them.

Akabane: And of course, other DAW users can use dspMixFx to utilize the exact same DSP functions.

dspMixFx is also available as an iPad app.

Akabane: When the UR series is used with an audio system app like Steinberg Cubasis, it is not possible to control the internal DSP functions without dspMixFx. Therefore, we developed the app. The iPad app version of dspMixFx is available as a free download from App Store.

Esashi: Another good point about dspMixFx is that the user interface is the same across all UR series models. So even if you buy a newer model from the UR series, you will be able to use it in the same manner as the previous model.

Luxurious two tone design by a global design team

Was there a concept behind the chassis design?

Akabane: We worked towards an appearance that resembled pieces of studio equipment but would also match computers at home. The design is done by an in-house team, but the team is global. We have full-time European and American staff on board. The first products, the UR824 and UR28M, were primarily designed by a German designer and were well received. The design concept was passed on to the UR22 and following products.

The UR series design is characterized by its two tone coloring, silver and black, and metallic plate enclosure. It may be hard to see from the photo, but we worked really hard on the texture of the silver areas. We were very particular about the texture of a computer made by a famous manufacturer.

What is the chassis made of?

Akabane: Steel. We thought a compact audio interface such as the UR series would not only be used in the home but also carried to live performances and other studios, so we made the chassis as strong as possible. Robust products are particularly popular in North America.

Does the steel chassis affect the sound quality in any way?

Koga: Yes, in a good way. Steel is resistive to the effects of external electromagnetic noise, and the grounding becomes more secure.



We hear that the UR series is a worldwide hit with the UR22 leading the way. What do you think is the reason for its popularity?

Akabane: I believe providing the customers with an audio interface that they wanted was what finally won the customers. No curves, just a straight ball. The driver performance is continuously improving, and comments on product stability and reliability are often spread by the word of mouth. Maybe our persistence finally paid off.

Koga: We are sure there are no other audio interface with mic preamps of this high performance, 192 kHz support, and built-in DSP at such an affordable price. Not to mention low latency and the amp simulator. I think the in-house development of the SSP2 chip was the key.

Akabane: Another thing to keep in mind is that the UR series comes with Cubase AI. So if you buy a product from the UR series, you end up with a music production environment. If you buy a UR12, you can start composing for about 10,000 yen. We have seen comments on the Internet stating that it has become a great era to be able to get all of this for merely 10,000 yen. Such comments make us really happy.

Are many of the users using Cubase?

Akabane: No, users use all sorts of DAWs. Pro Tools, Logic, Sonar, etc. I don’t see it being used more with a particular DAW. Recent market research shows that quite a few of them use several DAWs. For example, Cubase and Pro Tools or Cubase and Ableton Live.

Koga: One of the reasons why UR series became a hit is that Pro Tools decided to support Core Audio/ASIO. And another is the availability of the reliable MIDI interface.

The UR242 has just been released, but what products can we expect in the future?

Akabane: We can’t say anything about that right now, but we are obviously thinking about the next product. Please look forward to it.

Thank you for taking this interview.