Earlier this month Dave Nauber, Exec. VP, Brand Development of Classe, invited HTGuide to participate in a Q&A with him on the SSP-800 and other aspects of Classe. I wanted to post the result over here to spread it to a wider audience.
I realize there is some controversial opinion in this article. Please, lets not start a flame war. Everyone has their own opinion, and is entitled to it. If your opinion does not line up with Dave's, you are certainly allowed that, but the purpose of this thread is not to start a flame war. Just to share information. I tried contacting a mod in preperation to posting this to insure civility, but he was apparently not interested, as he didn't reply.
I thought about posting this in the "Amps thread", but I feel that it is more fitting to be here, because of its price range.
So here is the Q&A:
SSP-800 / Classe Pre-Pro's:
How Does it...
Q. With respect to the SSP 800 what exactly is it doing to a PCM signal which sets it apart from other SSPs? I assume that the DACs alone is not what separates the 800 from other SSPs.
A. PCM (Pulse Code Modulation) is the most common form of digital audio. It appears fairly simple, consisting of the data and the clocks. The data can be either a one or a zero, while the bit clock defines the moment when transitions between ones and zeros may occur. The basic idea is that you want the data to be accurate and the timing to be precise so that the signal gets put back together (turned into analog) exactly as it was taken apart (sampled into the digital domain).
Since cheap digital audio products can actually work, we know it isn't particularly expensive to get sound from a digital circuit. What is exponentially more difficult and expensive, however, is getting that last few percent of performance. This where the magic in high-end audio has always been.
It's hard to be both specific and complete when there are so many factors that contribute to the overall performance of the SSP-800. I can site specific examples like the processing power of the Texas Instruments DSP.
HD Audio involves more data than ever, so data integrity is a feature of processing power. Try to express the fraction 1/3 in the digital domain. You have 0.33333, which is an example of the fact that digitization involves approximation. With HD Audio, we are handling more data than ever and performing more calculations than ever. Having a DSP which can do many different tasks while also maintaining the highest precision was one of the objectives of the SSP-800 design. We use a Texas Instruments platform which can process at up to 1800 Million Instructions per Second (MIPS). Compare that with the most common DSP used in other processors (including one costing over $20,000) and you'll find them using a 300 MIPS part. Decoding Dolby TrueHD can use up about 270 MIPS, not leaving enough for EQ or other processor intensive post-processing functions. The TI processor works in 64-bit double-precision mode with floating point arithmetic (the decimal point can float anywhere in the number, giving small numbers higher accuracy). All this is to say that today, the SSP-800 has a monster of a processing engine. When the new dual DSP board is released, we will use a newer DSP chip, capable of up to 2800 MIPSand there will be two of them.
Other topics for discussion could be the masterful way power and ground are distributed within the 6-layer mother board, or how circuit trace lengths are calculated and optimized, or the use of LVDS (Low Voltage Differential Signaling) to minimize jitter (timing errors in the clock) and eliminate common ground between digital and analog signal paths. There's also our sample rate conversion and re-clocking of the signals entering the DACs, etc. But the key to it all is attention to detail throughout the design. I'm sure there are also some details I can't point out because our engineers have tended to them without even consciously thinking about it. Like a chef in a familiar kitchen, certain methods come naturally to an experienced professional.
We also consider the reliability and stability of the design and whether digital circuits create radiated or conducted noise that detracts from the performance of other nearby circuits. However, everything we do has a single clearly defined purpose: to supply the DACs with exactly what they need (accurate, precisely timed data and an incredibly low noise floor to allow the highest possible resolution and dynamic range).
The SSP-800 is special, but it does not owe that quality to any one part. I guess the cooking analogy works pretty well. Different chefs may have access to the same ingredients but come up with different results. Some are clearly better than others and sometimes two dishes might both be judged to be good, but the results appeal to different tastes. Using a more expensive wine in a reduction won't necessarily improve its flavor or texture, so it's both the ingredients and how they are used that matters. In the end we use our own senses to decide what works and what doesn't. The DACs themselves are only one (although not unimportant) factor in the overall results.
Q. Why not use the 1792 for all channels in such a high-end product, when some competitors appear to do so? Were certain tests performed to confirm no loss of quality using 1796? Especially since the difference in cost is negligable ($10 or so).
A. We believe that the total cost of parts in the SSP-800 is higher than any other processor priced below $10,000. In addition to spending a lot on parts, we are careful to allocate our Bill of Materials (BOM) budget by putting money where we find the most benefit. Although it is a high quality processor, the SSP-800 is not a cost-no-object product. We do not spend an extra $50 or even $5 on parts unless they return a comparable value in performance and/or reliability. Ultimately, each part is selected for its contribution to reaching our design goals.
The Burr Brown PCM1792 is used for the L, R, C, Sub, AUX1 and AUX2 channels. The PCM1796 is a pin-compatible package with the same silicon/structure as the 1792, so it was a simple matter for us to legitimately compare the two DACs in all locations. Our professional judgment was that the 1796s delivered maximum value in the Surround and Rear locations.
Q. Why did Classe not setup the 1792 DACs in dual-differential like the CDP-202 and the SSP-900?
A. The SSP-900 was a cost-no-object project, so it is worth noting that the SSP-800 uses the 1792 DACs in the same configuration as was intended for the SSP-900.
The CDP-202 is a superlative CD player. It uses 1792s in mono-mode and has separate DACs for the single-ended outputs, which we did not do in the SSP-800. The CDP and SSP have fundamentally different roles to play. They are fundamentally different designs and pointing out that the DACs are used differently is a good way of showing how we allocate the BOM budget in different ways depending on the design goals.
Q. With the SSP 800 being Classe Flagship Processor why ony 4 HDMI inputs?
Would you consider making a video board in the future that could be swapped out with the current board that offered more HDMI and fewer Component inputs?
A. I should begin by saying that the SSP-800 is indeed our flagship, but with the eventual discontinuation of the SSP-300, it will become our entry-level SSP as well as our flagship!
We obviously thought quite a bit about this before deciding on the I/O configuration of the SSP-800. Certainly the SSP-800 has fewer analog inputs and outputs than other SSPs, and this was done in recognition of the fact that sources and displays today are all migrating toward digital connections. Analog connections remain for compatibility with legacy devices. There is also a cost savings associated with fewer inputs and outputs, and the chassis can be 6 tall instead of 8.
We fully accept that the SSP-800 will not have every feature or provide every connection that any customer could want. We make this conscious decision to both limit the expense of the product and improve its performance and reliability. As we debated how many HDMI inputs, we concluded that the only sources that we absolutely needed HDMI for were HD-DVD and Blu-ray players. We want the audio from these sources arriving at the SSP-800 on HDMI. For all other sources, SPDIF is the standard connection and this can be handled by coax or optical.
For convenience, we expect a set top box (cable or satellite) will also be connected on HDMI and perhaps a dedicated high-performance DVD player like a CDP-300 or maybe a game console. Once you've connected those sources, well over 90% of the users have exhausted their supply of HDMI source components. For those few who have more than four, it's probable that the fifth or sixth most important video source is older (maybe DVI?) and could just as well be handled on component video.
Alternatively, sources that do not require HDMI for audio may be connected directly to additional inputs on the display or handled through an outboard switcher. These latter cases represent a very small minority of users and for them, there is really no performance compromise, just a little added expense or complication. We chose this approach rather than adding the cost burden for everyone to bear.
It might be worth adding here that all high-end companies, no matter how large or successful, are very small compared with the big CE giants. We pay more for basic parts than the big guys do, so adding more HDMI connectors and the associated switching capability (at our quality level) is simply more expensive. If we choose to pay for the extra features, we must either charge more or take money out of other areas. We don't expect everyone everywhere will agree with the choices we've made, but so far, we seem to have done pretty well with the SSP-800.
As for the question of a possible upgrade for additional HDMI inputs, sorry, but the answer is no. The only hardware upgrade paths that really make sense are those which are completely understood and planned for in advance, such as our dual DSP board replacement. You need to know how much space, how much power, how much heat, etc. that the future board will require, consume and generate, etc. before you can know if what you're selling today can be upgraded. You also need to know how the signals and power will be connected. Unless everything is clearly understood in advance, you will almost surely compromise performance and reliability when it comes to the upgrade. You will also add costs to units being sold today on the chance that additional power or connections or space may be required in the future, so the value proposition goes sideways very quickly in modular designs. They seem like a way to save money over time but they really don't.
Our approach is to design the SSP for as long a shelf life as we can practically imagine but to limit the future hardware ambition. In this way the product offers the best value, performance and reliability for everyone who buys it.
Q. Could you describe the topology? In particular, is it correct that for the balanced outputs, each DAC of the channel's pair feeds one of the two output polarities? And for single-ended outputs, is the signal driven from just the + DAC, or is the analog output configured as a differential stage fed by both the + and - DACs to take advantage of the improved noise floor with such a design?
A. Each PCM 1792 DAC provides differential outputs for two channels, so from the moment of D-to-A conversion onward, the signals are handled as differential signals. For the single-ended outputs, the non-inverting half of the differential signal is used. By using the recommended balanced outputs, you retain those benefits through to the amplifier.
Q. Our members are interested to know any thoughts or plans for additional surround processing modes that upmix from 2-ch and 5.1-ch sources. Interest has been expressed in Logic7, Trifield, THX, and Circle Surround. Do your designers/planners audition these various technologies to evaluate their merits? Are they not included because of licensing issues or because they are not sonically desirable?
A. This is potentially a wide ranging discussion, but I'll try to be concise. Whenever you create new channels where none had existed before, you have compromise. Matrix modes simply can never deliver the same experience as discrete channels can. Having said that, we know that some people really do like to listen to stereo CDs in multichannel and most of us can't resist choosing a mode that generates rear channel signals from a 5.1 channel source. In other words, these post processing modes have their place, which is why several are included among the modes offered by the SSP-800.
To include (or not) any particular mode depends on several conditions. Does it do what it is supposed to do, does it do it well and do or will enough people really want it? If the answer to any of these is no, we don't include it.
There are also practical concerns. Logic 7 is a Harman-owned feature and when I worked for Madrigal in the pre- and early Harman Specialty Group days, Lexicon wouldn't let us (Mark Levinson and Proceed) have it because we were seen as competitors. Although Harman is now under new management, I doubt their position will have changed. Another factor is that Logic 7 runs on an Analog Devices SHARC platform, so porting it over to our TI platform is not without its own development cost.
Trifield is available for license (not a Meridian-owned technology) but we haven't had much interest in it. Even THX, which in the days of analog surround made important contributions to standardizing system parameters and helping people understand the difference between a commercial movie theater and home theater, has now become unimportant to most users at the SSP-800 level.
By providing enormous amounts of processing power in the SSP-800, we keep our options open for additional modes like (potentially) Dolby PLIIz and Dolby Volume, both of which we have evaluated and are pleased with, and both of which are beginning to pick up traction among our customers. We still need to determine if there are any hardware limitations (I don't think there are) or if they will be too costly (we hope Dolby will be gentle with us), but they would be on my short list of future feature enhancements for the SSP-800.
Q. While no one has yet requested Neural 7.1, now that they are owned by DTS, and DTS (Neo:X) and Dolby (PLIIz) are both talking about additional channels, height and width, your thoughts on that would also be appreciated.
A. As I alluded to above, we believe the hardware will support the routing of other new channels to the AUX1 and AUX2 outputs. It is a little early to make any commitments, other than to say we are interested in some additional modes and are looking into the details. None are planned until after the dual DSP board is released.
Q. Could the AUX channels be used to support the Front High channels in Dolby PLIIz (or DTS's new format) or is there a hardware limitation that would prevent this?
A. As above. I don't expect a hardware limitation, but it's too early to say with confidence.
Q. Would it be possible to add Dolby Headphone processing? The lack of a headphone jack isn't necessarily a roadblock. Some processors use the "zone 2" outputs for the headphone signalsand Classe could use the Aux outs. If not DH, then some other suitable binauralizer process. Listening to "in the head" sound isn't that natural, and 5.1 downmixed to 2 often entails additional compromises, like reduced dynamics and loss of LFE. DH avoids that.
A. I don't know what DH requires of the processor, but it's not a feature very often requested. Many people are already using the AUX channels for bi-amping, subwoofers or down-mixing, so the DH users would be a subset of those who aren't yet using the AUX channels. I'm not ruling it out, just saying it hasn't risen to the level of consumer demand that would justify the project.
Q. There is interest in THX, and Dolby Volume. Will you add these in the future. If no, why not?
A. We launch a product like an SSP-800 with the features we feel it must or should have, then listen to what the market tells us. Our older SSPs were THX units and as the sources have moved toward digital and discrete, fewer and fewer people were using it.
We polled our dealers when the SSP-800 was in development and they suggested that it was no longer necessary. Like paying extra for parts that you don't need or features that few people use, every additional mode has costs associated with it. Sometimes there are royalties and almost always there are incremental development and support costs.
THX is not an a-la-carte proposition so it's not a matter of adding a mode and being done with it. In the case of Dolby Volume, there seems to be more interest, but it's on the back burner until we get the dual DSP board done.
Q. Could you confirm the basic operation of Classe's Music Plus and Movie Plus modes? Do we have it right that for 2-ch sources, Classe's Music Plus and Movie Plus is similar to Party mode, but instead of equal levels from all speakers, the center and surrounds are attenuated in proportions as on P32 of the manual. There's no other processing or filtering going on?
A. Not exactly. Party mode simply creates a monaural signal for distribution at equal levels to all speakers. Music Plus and Movie Plus modes are simple methods for taking a stereo source and creating a more enveloping sound field. They are not matrix modes like PLII or Neo: 6, but rather stereo modes with different mixes of front/surround and center channel balance. In the Movie Plus mode, relatively more signal is fed to center and surrounds than is the case with Music Plus. For Movie Plus, the center channel is at 60% (vs. 25% in Music plus) of the front L&R while the surrounds are at the same relative level as the front L&R (vs. a 70%/30% split of L&R/Surr in Music Plus mode). If you have them, rear channels are at 15% of the front L&R levels in both modes. Keep in mind that your relative attenuation of each channel in the system also plays into the level you actually hear from each speaker group. We offer the modes because they are a different flavor, preferred by some people on some recordings and simple, easy to execute (as in essentially free).
Q. When Dolby True HD and DTS MA become available with the upgrade, we assume all the same post-processing modes and options available for other 5.1 sources remain in full effect. Is that correct?
A. Yes. (Finally, a short answer!).
Q. What does it do with sources like 3-channel or 4 channel SACD or DVD-Audio? In the case of 3-channel SACD, does it keep the center channel? In both cases what does it do with the other output channels? Are they processed or are they silent?
A. The only way an SACD player could deliver more than two channels in the digital domain would be over HDMI. Although the hardware could technically support DSD over HDMI, we don't do it because you'd have to convert the DSD signal to PCM for processing and D-to-A conversion. For DSD, this is literally throwing the baby out with the bath water. We provide multichannel analog inputs for this scenario, because you want the SACD player to do all the processing, keeping everything DSD until the moment of D-to-A conversion. We do not process these analog inputs because your SACD player should provide whatever multichannel processing you need for your system. Playing SACDs and converting them to PCM (as some players do) or worse yet, converting them to analog and then back to digital PCM for processing and then back to analog seems a terrible waste.
For four-channel DVDs, the post-processing algorithms from Dolby and DTS can be used to create the extra channels in your system configuration. I don't know how their algorithms work, but you can use them with these sources.
Q. Would Classe consider expanding the ability of their upmixers to process 3-ch L-C-R sources (i.e., RCA Living Stereo recordings)? This could be done either by means of new surround processors (Like DL7 or Trifield) or possibly by means of PLII/PLIIx which we understand from Dolby would be a relatively minor engineering task.
A. If I had a Living Stereo three channel LCR recording, I think that's the way I would listen to it. That's my initial reaction anyway.
Q. Our members are keen to hear more thoughts and background on the current PEQ and any future potential for automated room EQ. Members do understand the issues with of existing solutions from Audyssey (inconsistency, inability to tweak except the Pro versionwhich requires a Pro license), or ARC (some flexibility in bandwidth and room gain). Others appreciate the ability of PEQ to be totally controlled, yet to do so effectively requires a pro (or lots of learning and good tools) as well. Would you be willing to offer Auto-EQ (Audyssey, or Trinnov, for example) as an a-la-carte option for customers as an alternative to, or maybe on top of PEQ, so you don't lose potential customers that feel it is the got-to-have feature?
A. Probably not. I don't see the benefit of combining automatic and manual EQ. If you need manual adjustments to get it right (which you do), why bother with doing anything automatically?
Classé is and always has been an audio company. We have a love of sound that transcends technology, product and market life cycles, and are home to some of the best designers in the world. As specialists, we sometimes have to take a stand and tell people the truth, even if it's not what they want to hear and even when it costs us sales.
I think this is just such a case. Rather than expand the feature set so we can sell a few more units to misinformed customers, we are prepared to take a stand against the misinformation and hype. It won't be the first time!
To explain our position, we have to start first with what equalization cannot do. Equalization can't correct a room. Period. Whether automatic or manual, a PEQ can make improvements, but don't confuse better or different with optimum. Sorry, but there really isn't a shortcut here. In the hands of a professional, a manual parametric EQ can be a useful tool, but you still need to treat the room, have good speakers with good off-axis response, put them in the right locations, have equally good low-noise, low-distortion electronics, etc. These are the building blocks of great sound.
Sound waves traveling through the air are fragile, volatile and infinitely complex. The software that performs automatic room correction is sophisticated indeed, but even if it could exercise judgment, like a human, it wouldn't be able to overcome the limitations inherent in equalization. So how much do you want to pay for a tool that doesn't actually do what you want it to do?
We will undoubtedly lose some sales due to misrepresentations of the power of automatic systems. If you take the time to listen to competing models or think logically about the futility of Auto EQ, I think the SSP-800 becomes a pretty obvious choice.
Q. I think that most of us would like to know what the new DSP could be used for besides bitstreaming of codecs. would you share with us what else it WILL be used for that would be great. Also, what are POTENTIAL uses? If we have that information, then we could have an interesting discussion.
A. when the dual DSP board is released the only new feature will be HD bitstream decoding. All other uses would fall into the potential category, such as tone controls, Dolby PLIIz and Dolby Volume. I am also assuming that we'll have some other modes or enhancements in the future that will utilize the available horsepower, so we aren't in a hurry to use it up. We expect the SSP-800 to be a current model for years, so it will evolve with the times.
Why was this feature left out?
Q. DSD Support? Is this something that could be added later?
A. This is not likely. I talked about this earlier in the context of three-channel matrix mode options, but will reiterate a few points. The benefits of DSD (SACD) recordings get thrown out once you convert them to PCM. You want to convert DSD signals to analog without ever converting them to PCM. This requires a different digital signal pathall the way up to and including the DACs. This is why adding SACD to a CD player is an expensive proposition if you want to do it right. The only way for a surround processor to optimize DSD performance is to build a parallel digital signal path inside to be used only by those recordings. Seems like sheer madness to me. Just convert it to analog in the player and let us take it from there.
Q. Video Scaler? Since the video board appears to be removeable without removing anything else, could you a-la-carte a video scaler into the SSP-800 like Bryston is offering with the SP3?
A. No, we don't believe this is the correct/best place to perform the scaling function. In 2009, if an audio company can do scaling better than your video display manufacturer, you probably need a better video display, not another scaler.
Q. What would cause classe to do a whole re-design on the Delta series? Is it safe to say Classe wont change the look for some time?
A. Yes, it's safe to say we will keep the Delta series Industrial Design for some time. We are preparing to launch a Custom Theater series (shown last September at CEDIA) which is developed for custom installations such as rack mount and enclosed cabinets where ease of installation and management of heat are particular problems to solve. These are black/dark grey units in more conventional rectangular chassis. The SSP-800 will be produced in one of these chassis and called a CT-SSP (same price, same everything).
Q. There have been a few software issues that Classe has been addressing that have prompted new code every couple of months. Where are we in terms of bugs in the software at this point, and how long does Classe see it taking before they are mostly non-existent?
A. There have only been two updates since the September launch and the v1.0.2 code meets your mostly non-existent standard for know issues. This means that anyone can buy an SSP-800 and be confident that it will perform beautifully. Our current priority is to focus on the dual DSP update and I think most SSP-800 owners would agree with us on this.
Q. Instead of configuring the processor via OSD are there any plans to provide possibility to do configuration on the pc with the client application? Also do versioning different configurations on the PC and load them into the processor after finished with the setup on the PC?
A. This is something we have discussed but it isn't a high priority (compared with finishing the dual DSP and the CT series). I can set up an SSP-800 faster from the front panel than I could from a PC, if you include the time to turn the PC on. In other words, I don't disagree that some dealers would find it useful, but don't think it's as important as many of the product features we have been discussing.
Q. Are there any plans to provide other controlling mechanism than Irda or RS-232 like controlling from PC client via USB or Canbus. If canbus, it's usage would require LAN TCP/IP connectivity?
A. No. The RS-232 and USB currently allow bidirectional control which works well for system automation. CAN Bus was never intended for such a broad application, so it is not suitable (nor would it be a real benefit).
Q. What does the Test e-mail option at the Can bus menu mean?
A. There is an outboard box called the Messenger which is currently under development. It connects CAN Bus to your LAN to provide a means for alerting the installer to an amplifier protection circuit event. It does so by sending an email to the installer and Classé over a LAN connection. The test email button is provided for that future application as a way to test that the setup is working properly.
Q. I would like to see more enhanced product documentation at this price range. Some of the discussion and debate could be avoided by extending the depth of documentation e.g. sound processing, etc. It would propably speed up people to get most out of their Classe components as well.
A. I'm not sure why it has anything to do with the price level, but we can try to improve this if given enough feedback. The manual is already over sixty pages (in English only) so we'd rather not to kill any more trees than necessary. I would like to focus on clarifying things that are unclear and adding only those things which truly help someone get more from their SSP-800. Feel free to comment.
Q. Why is no trade-up offered for existing SSP-300 / SSP-600 customers?
A. If we used the normal cost multipliers for our industry, the SSP-800 would be priced at $11,000. There simply isn't the margin to do it at $8,000. I am familiar with other SSP upgrade programs and I can assure you that the retail price of the component always has this built into the margin. If we sold the SSP-800 for $14,000 (where it would still be competitive), then we could offer a generous trade and still make good margin. We went for the lower retail with its lower margin instead, since there will not be a lower priced SSP coming from Classé any time soon (if ever). The SSP-800 is both our new entry-level and flagship SSP.
Q. Are there any plans for a successor to the SSP 300?
A. No. See above. The cost of building truly high-performance SSPs is high and going higher. I doubt the trend will be reversed.
What was Classe's methodology to determining what features would and would not be included in the design and build of the SSP-800?
A. Our design requirements are based on experience, market analysis and feedback from the front lines. We build what we would like for whatever the intended application. We do not try to be all things to all people, but build ultra high-performance components that anyone would be proud to own.
I need more than 4 programmable function banks. Could classe devise a way to allow this, such as by using key combinations?
A. The remote control is an example of not being all things to all people. I don't think there is any one remote that can satisfy the diverse needs of more than about 10% of the users, so we decided to make one of high quality but the most basic functionality. There are after-market remote control solutions all up and down the price spectrum and with the discrete IR codes, you can tailor one to do exactly what you want to do.
Is it possible to add the display timeout to the Canbus features and turn the Classe amplifier channel light off (not just dimmed) and on in sync with the display time out?
A. No, we need to indicate that the amplifier is on (safety requirement) and distinguish its operate mode from its standby mode.
Q. How many SSP-800's have sold so far, and is there still a back-order situation?
A. We've sold over 500 so far and have been shipping from stock for several months now.
Q. Has the SSP-800 reached or exceeded sales expectations?
A. It's exceeded our expectations, even without considering the tough economic times we face. The performance and reliability have proven to be exceptional and it has become the high-end processor to buy. We obviously have very limited distribution, so there are other processors getting sold by dealers who don't have access to Classé, but overall it looks like the SSP-800 has taken a huge share of this very high-end market.
ask not what you can do for your country, but what your country can do for you.