Dear Mr. Pass,
I trust this letter finds you well and deeply immersed in your timeless pursuit of audio perfection. Your contributions to the high-fidelity world are legendary, marked by a philosophy that prioritizes purity, simplicity, and the profound, subjective experience of music. It is precisely against this backdrop of established excellence that I feel compelled to outline a future that, while perhaps divergent from your preferred path, is rapidly becoming the dominant force in the audio industry: the symbiotic rise of Digital Signal Processing (DSP) and Class D amplification.
My aim is not to diminish the artistry and sonic character of your designs, but rather to present a pragmatic view of market trajectory and the relentless pursuit of "hyper-optimization" that now drives competitiveness in nearly every technological sector.
For many years, Class D was viewed with skepticism in high-end audio, often associated with harshness or a lack of musicality. Similarly, DSP was often seen as a necessary evil for managing digital formats, rather than a fundamental tool for sonic refinement. However, the landscape has fundamentally changed.
Class D Amplification: Efficiency as the New Frontier
The advancements in Class D technology are no longer incremental; they are transformative. We are witnessing:
DSP is no longer just for basic equalization. It has become the central nervous system of modern audio systems, offering unparalleled control and optimization:
In today's globalized and fiercely competitive markets, companies can no longer afford to rely solely on incremental improvements or niche appeal. The era of hyper-optimization is upon us, and it is what drives market dominance.
Hyper-optimization is the relentless pursuit of maximizing performance, efficiency, cost-effectiveness, and user experience across every facet of a product's lifecycle. It is characterized by:
Mr. Pass, your legacy is built on the pursuit of "less is more" in analog design, emphasizing directness and minimal interference. It's a profound and valid philosophy for a specific ideal of audio reproduction. However, the "more" that DSP and Class D bring today is not arbitrary complexity; it is highly intelligent, highly efficient, and ultimately, provides a level of control and objective performance that is increasingly difficult for traditional analog approaches to match on a broad scale.
The industry is moving towards systems where the amplifier and the loudspeaker are intimately integrated, where the room itself is treated as part of the acoustic equation, and where software defines much of the listening experience. In this future, DSP is not merely an add-on; it is foundational. Class D is not merely efficient; it is the economically and environmentally sensible path to high power in compact forms.
The question for the high-end audio industry, then, is not if DSP and Class D will dominate, but how established purveyors of quality will adapt. Will it be through integration, finding ways to apply these powerful tools to enhance the subjective experience without sacrificing artistic integrity? Or will it be a steadfast adherence to traditional methods, appealing to an ever-smaller, albeit dedicated, segment of the market?
I believe there is a path forward where the elegance of analog design principles can inform, but not restrict, the adoption of these powerful digital and switching technologies. The art of the listening experience remains paramount, but the tools with which we achieve it are evolving at an unprecedented rate, driven by the imperative of hyper-optimization.
Thank you for considering these thoughts.
I trust this letter finds you well and deeply immersed in your timeless pursuit of audio perfection. Your contributions to the high-fidelity world are legendary, marked by a philosophy that prioritizes purity, simplicity, and the profound, subjective experience of music. It is precisely against this backdrop of established excellence that I feel compelled to outline a future that, while perhaps divergent from your preferred path, is rapidly becoming the dominant force in the audio industry: the symbiotic rise of Digital Signal Processing (DSP) and Class D amplification.
My aim is not to diminish the artistry and sonic character of your designs, but rather to present a pragmatic view of market trajectory and the relentless pursuit of "hyper-optimization" that now drives competitiveness in nearly every technological sector.
The Inevitable Rise of DSP and Class D
For many years, Class D was viewed with skepticism in high-end audio, often associated with harshness or a lack of musicality. Similarly, DSP was often seen as a necessary evil for managing digital formats, rather than a fundamental tool for sonic refinement. However, the landscape has fundamentally changed.
Class D Amplification: Efficiency as the New Frontier
The advancements in Class D technology are no longer incremental; they are transformative. We are witnessing:
- Near-Perfect Efficiency: Modern Class D amplifiers routinely achieve efficiencies upwards of 90%, far surpassing the inherent limitations of Class A (often below 20%) and Class AB (typically 40-60%). This is not merely an academic advantage; it translates directly to:
- Reduced Heat Generation: Smaller, lighter heatsinks, or even no heatsinks at all, leading to significantly smaller form factors.
- Lower Power Consumption: Crucial for environmental concerns, portable devices, and increasingly, for home power grids struggling with demand.
- Cost Reduction: Fewer and smaller components, simpler thermal management, and streamlined manufacturing processes directly reduce production costs. This allows manufacturers to deliver high power output at price points previously unimaginable.
- Sonic Maturation: Through sophisticated modulation techniques, advanced feedback loops, and vastly improved output filter designs, the "sound" of Class D has evolved dramatically. Today, top-tier Class D modules from companies like Hypex, Purifi, and ICEpower are achieving distortion figures (THD+N) that rival, and often surpass, even the most meticulously crafted linear amplifiers, across a wide bandwidth. The perceived "harshness" is largely a relic of earlier generations, overcome by intelligent engineering that leverages the speed and precision of digital switching.
- Miniaturization and Integration: The small footprint and low heat of Class D enable highly integrated solutions – amplifiers that can be built directly into active loudspeakers, streaming devices, or even compact, all-in-one systems. This streamlines the user experience and reduces system complexity for the end-user, a powerful market driver.
DSP is no longer just for basic equalization. It has become the central nervous system of modern audio systems, offering unparalleled control and optimization:
- Precision Room Correction: Every listening room introduces acoustic anomalies. DSP, through sophisticated algorithms, can precisely measure and correct for these imperfections, transforming a challenging acoustic space into an optimized listening environment. This "corrects" the speaker-room interaction in a way that no amplifier, regardless of its linearity, can achieve on its own.
- Active Crossovers and Bi-Amplification: DSP enables active crossovers with incredibly precise slopes and phase alignment, allowing for multi-way speaker designs that are perfectly integrated. This is a level of control and accuracy simply not possible with passive crossovers. Furthermore, it facilitates true bi-amplification and multi-amplification with independent control over each driver, leading to vastly improved dynamics and clarity.
- Time Alignment and Phase Coherency: Achieving perfect time alignment between drivers, and correcting for phase shifts introduced by speaker design or room reflections, is a critical factor in creating a cohesive soundstage and accurate imaging. DSP can perform these corrections with microsecond precision.
- Adaptive and Personalized Audio: Imagine systems that dynamically adapt to listening volume, content type, or even learn individual listener preferences. DSP allows for personalized sound profiles that go beyond simple tone controls, offering tailored experiences that appeal to a broader market segment.
- Future-Proofing and Feature Agility: A DSP-centric design allows for software updates to introduce new features, improve performance, or adapt to new audio formats, without requiring hardware changes. This level of flexibility is a massive competitive advantage.
The Imperative of Hyper-Optimization
In today's globalized and fiercely competitive markets, companies can no longer afford to rely solely on incremental improvements or niche appeal. The era of hyper-optimization is upon us, and it is what drives market dominance.
Hyper-optimization is the relentless pursuit of maximizing performance, efficiency, cost-effectiveness, and user experience across every facet of a product's lifecycle. It is characterized by:
- Data-Driven Design: Leveraging vast datasets and computational power (often AI-assisted, as I mentioned previously) to explore and validate design parameters that would be impossible for human designers to evaluate manually. This leads to designs that are objectively superior across measurable parameters.
- Iterative Refinement at Speed: The ability to rapidly prototype, test, analyze, and refine designs with unprecedented speed. This accelerates product development cycles and allows companies to quickly respond to market demands and competitive pressures.
- Component-Level Efficiency: Squeezing every last bit of performance and efficiency out of each component, optimizing its interaction within the larger system. This is where the inherent advantages of Class D's efficiency and DSP's control become paramount.
- Holistic System Optimization: Moving beyond optimizing individual components to optimizing the entire audio chain – from source to speaker – as a single, cohesive system. DSP is the key enabler here, allowing for seamless integration and optimization of every link in the chain, adapting to the specific speaker, room, and listener.
- More Affordable: Due to reduced manufacturing costs.
- More Feature-Rich: Thanks to DSP's versatility.
- More Convenient: Due to smaller size and lower heat.
- Objectively Better Performing: Through data-driven design and precise system-level correction.
A Shifting Paradigm
Mr. Pass, your legacy is built on the pursuit of "less is more" in analog design, emphasizing directness and minimal interference. It's a profound and valid philosophy for a specific ideal of audio reproduction. However, the "more" that DSP and Class D bring today is not arbitrary complexity; it is highly intelligent, highly efficient, and ultimately, provides a level of control and objective performance that is increasingly difficult for traditional analog approaches to match on a broad scale.
The industry is moving towards systems where the amplifier and the loudspeaker are intimately integrated, where the room itself is treated as part of the acoustic equation, and where software defines much of the listening experience. In this future, DSP is not merely an add-on; it is foundational. Class D is not merely efficient; it is the economically and environmentally sensible path to high power in compact forms.
The question for the high-end audio industry, then, is not if DSP and Class D will dominate, but how established purveyors of quality will adapt. Will it be through integration, finding ways to apply these powerful tools to enhance the subjective experience without sacrificing artistic integrity? Or will it be a steadfast adherence to traditional methods, appealing to an ever-smaller, albeit dedicated, segment of the market?
I believe there is a path forward where the elegance of analog design principles can inform, but not restrict, the adoption of these powerful digital and switching technologies. The art of the listening experience remains paramount, but the tools with which we achieve it are evolving at an unprecedented rate, driven by the imperative of hyper-optimization.
Thank you for considering these thoughts.
Keep in mind I already debated ASR and it's nothing but censored information with carefully designed narratives to deceive the public.
The future of class D in my opinion is a distortionless modulator (ESSish) into a gate driver....just do it on an FPGA dude...
The future of class D in my opinion is a distortionless modulator (ESSish) into a gate driver....just do it on an FPGA dude...
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Observing the market and number of users that has "olden" gear running, its is so vanishingly small compared that as I see it, the ones that want to run a class-A amp may very well do so without having to feel guilty about it. If one like the reproduction quality, the better.
Me, is all for DSP and class-D.
The rest, the vast majority - don't have a clue.
//
Me, is all for DSP and class-D.
The rest, the vast majority - don't have a clue.
//
Yeah? Did you get banned?
Other than that, your presentation reads more like sales literature than a sober review of where class-D stands today, any remaining issues, what it can and can't do, etc.
Also, I gather from a professional speaker designer that over reliance on frequency domain analysis and standard measurements is a common problem around here and in the audio world in general. Didn't see much in what you wrote to dispel that concern. THD+N, really? What about more complex phenomena? (e.g. signal-correlated noise? settling time on large signal transients? etc.?)
In addition, haven't tried class-D myself in a while, but maybe you can at least provide an update on how is it doing in terms of reproducing stable ITD lateral localization cues, as well as depth cues to create virtual soundstage images between and behind speakers? Is it better than the best we can do today with our old analog space heater amplifiers? If so, how did you measure those things in order to come to your conclusion?
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still there is no dsp available below 100 bucks the wondom stuff not taken into account as it is not ready to use.
the cheapest decent eq is behringer fbq1502 for 85 euro
the cheapest decent eq is behringer fbq1502 for 85 euro
"Hyper-optimization", "imperative", "dominance", "industry movement" are words for mass market, big industry, main stream, big money etc.
You are right, but nothing new and kind of pointless when targeted to a niche DIY community.
Class-A, good class AB, tube amps, horn speakers, passive speakers, analog eq etc, are for niche market not big industry, which needs to lead the herd to the same very controlled direction.
It's similar to post EV new trend article saying that "EV is the future", "nothing will stop it", "gas engine is dead" in a vintage gasoline muscle car forum, where people love to discuss about carburetor options, customizing gear boxes etc.
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Why is this adressed to Mr. Pass?
Do you want him to aknowledge he is waisting his talents on dinosaur technology.
Convert him, before its too late. Perhaps when this bright future of DSP and class-D has gotten rid of all that old stuff, which really has no right to exist anymore, they will say he was on the wrong side of technology progression…
Do you want him to aknowledge he is waisting his talents on dinosaur technology.
Convert him, before its too late. Perhaps when this bright future of DSP and class-D has gotten rid of all that old stuff, which really has no right to exist anymore, they will say he was on the wrong side of technology progression…
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AFAIK Mr Pass did develop a class D amplifier in the past. It seems the company is not so much into modern/complex/high tech stuff as this is not what the customers desire.
diy electronics is difficult with smd components.
To learn and practice electronics you need the basics of former times.
Usually the big industry would like all smaller companies to die so that profit could be maximized.
Just think of the pharma industry prohibting by its influence the promotion of herbal drugs although this is not a big market.
To learn and practice electronics you need the basics of former times.
Usually the big industry would like all smaller companies to die so that profit could be maximized.
Just think of the pharma industry prohibting by its influence the promotion of herbal drugs although this is not a big market.
Feature-rich software-driven electronics is difficult to DIY, unless coding is your thing. Then do you build the host computer, or use somebody else’s design?
People, at least a few of us, will continue to build analog with transistors for the same reasons that some are still using tubes.
If I wanted to stay current on technology, I would have just kept my job and kept working till the day I die. Things were evolving there, similarly to the evolution in audio. In directions I didn’t feel the need to go.
People, at least a few of us, will continue to build analog with transistors for the same reasons that some are still using tubes.
If I wanted to stay current on technology, I would have just kept my job and kept working till the day I die. Things were evolving there, similarly to the evolution in audio. In directions I didn’t feel the need to go.
Class D is not well-suited for true DIY; it's too complicated. The closest you can get to DIY with Class D is assembling pre-made modules into some sort of setup. Some people might even go as far as buying an expensive cabinet and installing a car radio that costs only 30% of the cabinet’s price.
Who cares? When it performs right all is good. Also depends if either DIY or playing back music a nice way is the goal.
If you are long enough in this hobby you will notice a considerable number of audio aficionados with strong preferences for topology A or B, obsolete parts etc. only rarely really use the equipment let alone to play back an entire album.
If you are long enough in this hobby you will notice a considerable number of audio aficionados with strong preferences for topology A or B, obsolete parts etc. only rarely really use the equipment let alone to play back an entire album.
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Not necessarily. Many SMD components can easily be hand soldered with a little practice and a few of the right tools.
One of the things missed in the OP presentation is how DSP is being used - to apparent success - in sound modeling. It's also possible that this paradigm will bleed over from instrument amplification to HiFi sound reproduction, though what the model churns out may be far more subtle in the case of HiFi.
Want to listen to LS3/5As instead of the speakers you have. That should be possible. Want to listen to a Dynaco MKIII instead of your Oh so pure class D amps? That should be possible. Want your room to disappear and be replaced with the acoustic environment of a famous club or theater? That should be possible too.
This is an entirely different direction than trying to reproduce the sound of your father's old all-tube Dynaco setup with the AR3a speakers you remember the sound of from when you were a kid. This is more like a "Cello Palette", but in addition to frequency band levels, you get screws for all aspects of how something sounds.
As compelling, that might be like having 50 wives. You can even remember all the names of what the super-optimized DSP can do. Methinks even with the offer of infinity, it will be all too much for many who simply want to flick a switch, startup a table spinning and cue up a selection.
I suppose an anology would be a modern car. Giant LCD screen, self driving... Give me something I can simply put a physical key into, turn it on and go. Take the computer assist dollars and invest it into the engine, chassis and drivetrain structure instead.
Want to listen to LS3/5As instead of the speakers you have. That should be possible. Want to listen to a Dynaco MKIII instead of your Oh so pure class D amps? That should be possible. Want your room to disappear and be replaced with the acoustic environment of a famous club or theater? That should be possible too.
This is an entirely different direction than trying to reproduce the sound of your father's old all-tube Dynaco setup with the AR3a speakers you remember the sound of from when you were a kid. This is more like a "Cello Palette", but in addition to frequency band levels, you get screws for all aspects of how something sounds.
As compelling, that might be like having 50 wives. You can even remember all the names of what the super-optimized DSP can do. Methinks even with the offer of infinity, it will be all too much for many who simply want to flick a switch, startup a table spinning and cue up a selection.
I suppose an anology would be a modern car. Giant LCD screen, self driving... Give me something I can simply put a physical key into, turn it on and go. Take the computer assist dollars and invest it into the engine, chassis and drivetrain structure instead.
