Announcement

Collapse
No announcement yet.

Class D (Switching) Amps

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    I am very proud to be announcing shortly the Project Oganesson line of amps. This is nothing like Class D or any other class. You can listen to them at a place near you and Myles will be doing a review shortly - I am late shipping these amps to him.
    Some of you know that I have had the best implementation of the Hypex NC1200 which Myles had reviewed a short while ago. While good, it was still lacking some finesses and air. The Hypex modules rely very heavily on feedback to quell the switching issues and thereby miss the details. The Hypex power supplies while good are still generating noise under load, even though this is below the distortion levels.

    The new Project Oganesson Amps have a few characteristics in their design unlike any other. First Gallium Nitride Transistors are used. These are the most advanced transistors which were only introduced commercially a few years ago. They operate in the Gigahertz very cleanly. Most equipment and components are measured with a sine wave. However music is closer to a square wave causing a lot of issues. The Gallium Nitride Transistors are unique because they have very, very little capacitance which allows them to switch fast on a square wave without overshoot and ring by an order of magnitude.
    Secondly Project Oganesson uses a proprietary ZXOL, which is an open loop design - no feedback. You can hear all the details without the exaggerated highs. And it is fast without any edge for the overshoot and ring, which is even common on other class amps.
    A new custom power supply was design using the LLC concept. LLC uses the transformer as an inductor. The power supply changes to accommodate the load, hence will be the same delivery of power from no load to full load. It is also significantly quieter.
    Finally the circuit board and layout was thoroughly investigated used advanced software to reduce the parasitic inductance and capacitance to near zero. This allows design that are close to the Theoretical design and really pushes the limits on what can be done.
    As usual every other aspect was also considered from the Silver plated, OFC telfon sleeved wire through out to the pure copper WBT speaker posts. Furutech 20A IEC AC inlet is used for a tighter connection even though there is no 20A requirements. Isoacoustics GAIA foots are used to provide isolation as well as damping pads for mounting the circuit boards. 16 pounds of pure copper was used as the heatsink for fast heat dissipation keeping the units near constant operating temperature for more linear performance. Component tolerance was kept to 0.1%.

    The result is a very quiet system that is very music, and plays huge amounts of details, a sound stage that is wider and deeper. Remember the source is as important and you are ultimately limited by the worst link in your system. So the most revealing systems are the best to hear the most out of these amps.

    Early test customers were very, very impressed listening to the prototypes. We will be showing the new amps at Munich High End Show Atrium 4.2 E226 with CEC. I owe Myles a pair for review also for Positive Feedback.

    Take a listen when you can. Starting in NJ at Distinctive Stereo, The Art of Sound. The list will be expanded as we get more units out there. You will be surprised at how much you can hear and how quiet and so musical they sound. Of course all manufacturers say they have they best amp. Take a listen and decide for your self. Regardless this is an implementation that will challenge any class of amp at any price.
    Merrill Audio.

    Comment


    • #47
      No link? Ballanced only? Price?
      PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI preamp,
      Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
      Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects.

      Comment


      • #48
        All of Merrill's amps and preamps are balanced only. There's no link as there are only placeholder pages on the Merrill website as of this AM. The price for the larger amp is $32000: https://www.audiogon.com/listings/li...on-solid-state

        Comment


        • #49
          On another thread I can not find, Al was talking about how amps soft clip via compression of sound stage and loss of information. The amps I believe he was referring too were tube of course and maybe A and AB. I have been running a set of class D amps in my system for a week or so now. I kind of turned them up today without any issue. They are 60 watt per channel. I was wondering if Class D also does this, or if it just a hard clip. You know, the big band and snap people talk about.

          I am asking as I am wondering how do I know when I'm getting close to clipping the amp. I don't want to damage anything. I don't hear any compression or loss of bass when I turn it up. I'm thinking of using these amps in a biamp scenario and they will be driving the woofers. I have had some parties when things get out of hand and the stereo get turned up to 11. I need to know if I am setting myself up for an issue. At least one thing I have going for me is a resistor stepped ladder attenuation that I can bottom out with my current tube amps and not hurt anything. This little class D amp was getting pretty darn loud and I had a few notches to go. I was a little worried if I pushed it harder bad things might happen. I mean seriously. How can a amp with 4 caps, no larger than my ring finger, weighing less than a pound play so loud and with such forceful bass. I don't get it, and I don't want to find out the hard way where it all needs to stop.

          Thanks
          PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI preamp,
          Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
          Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects.

          Comment


          • #50
            Maybe someone can chime in and help me with something.

            I don't understand the use of class D in an audiophile class amp. Everything about an amp is about modulating the power supply to produce a carbon copy of the input signal. Introducing switching into the power supply and the output devices sounds like an invitation to introduce non-linear content into the output.

            The very best traditional amps are all about their power supplies and the ability to supply instantaneous current into a difficult load (the speaker) during a very demanding program source. Adopting a switching approach into this arena certainly introduces efficiency but what are we doing to the output signal?

            Each time I read about a class D amp, I hear reports about different sounds that these devices introduce. This sounds like an approach that would be welcomed for other amplification purposes but for absolute fidelity it sounds like a wrong turn.

            I am sure some of these are much better than others but for absolute fidelity I find the approach absurd. When we want efficient amplification class D makes all the sense in the world. When we want absolute fidelity class A is the best approach and I have never heard anyone argue otherwise.

            The KISS principal still holds true no matter how much someone may argue for some other hi-tech approach. We wandered away from tubes in the 1960s when everybody saw the amazing efficient solid state devices.. Then someone compared a solid state amp to a tubed amp and listened.

            To be sure the tube amp sounded better than any early transistor amp and that still holds true today. The high end is not about efficiency or compactness, its about fidelity. The old vacuum tube makes music better than sand. The transistor can sound pretty dammed good, now that we have has decades to learn what was right and wrong, but for absolute sound quality the tube is still king.

            It isn't efficient and wastes lots of power and space but who cares? That isn't what this hobby is all about. And that really irritates a lot of people who do not understand why we all spend so much on such antiquated equipment. We could make music with a smart phone and some bluetooth earbuds. Why do we all insist on such old fashioned stuff?

            All of the above comes to mind when the subject of class D amps come up. It seems to be another modern device that has great potential. What does it sound like compared to an old-fashioned all class A amp?

            And that is why we do what we do.

            Ed
            Life is analog...digital is just samples thereof.
            https://www.edsstuff.org

            Analog: VPI Prime, 3 Belt Drive, Dual Pivot, ADS, Ortofon Windfeld Ti, Liberty B2B-1, Sky 30 Trans, Stereo Squares Dust Cover
            Amp: Rogue RP-9 + Schiit Loki + Parasound A21
            Speakers: Magnepan MMC2 + DW-M + REL T5/i
            Digital: TASCAM UH-7000, Pioneer DV-47Ai, NAD C446, Schiit Modi Multibit
            Headphones: Stax Lambda Pro, Focal Clear, Schiit Lyr 2
            Wires: Kimber Hero + 8TC + AQ Leopard

            Comment


            • Rob
              Rob commented
              Editing a comment
              Ed, have you used an ncore-based class d amp or the like in your system?

            • EdAInWestOC
              EdAInWestOC commented
              Editing a comment
              From what I wrote I guess its pretty obvious I don't, but to make it official, no I've never used one of those. That's the reason I sort of asked whats up with these amps. I don't trust something that relies on switching to provide its power. Unless it has 100% resources available all of the time, how can it absolutely reproduce what it must? Relying on switching means there are times when it is off. How ever brief that interval may be, it cannot provide what it must until it switches on again.

              When it comes to music, how can that provide what must be provided all of the time? And yes, these are questions.

          • #51
            I'm kind of asking part of what your aluding to Ed. Does class D have instantaneous power and hard clip when it cant provide, or does it indeed start to soft clip and loose dimension , compress the signal and poof on the bass. But more important for me, without a meter on the front, is there any way to know if your near it's end.

            As per it providing "audiophile" sound. Well, has anyone found the perfect amp. I have had 3 tube amps and 2 class A /AB amps and they have all been good but also had faults. They all have a color and sound.

            The biggest unrelenting sound issue I have run into with Tube and SS is buzzing. Buzzing mechanically and or through the speakers. Buzzing had been an unrelenting thorn in my side as well as friends of mine. I have tried multiple types of powering condition to some benefit or no benefit. It really depends on what I tried and what I connected it to. But in the end none of it made the amp perfect.

            I also have friends with systems that may be $300,000 or $500,000 in value and still they fiddle modify and adjust and at times talk about tossing the whole system and starting over. Is there really anything that is so pure and perfect in its design that no other topology would be acceptable?

            One thing this class D amp has done for me is absolutely completely and totally remove every bit of buzzing from my system. I'm talking this little amp is dead dead dead quiet. I don't think I realized how irritating and distracting and generally messing with the sound I was getting from all the buzzing that came from every other amplification system in my setup, until I heard this class D amp. It may not be perfect, but it is so much more calming and relaxing to sit in front of and listen to music. And I believe a big part of that is the clean background the music rises out of. Even outside of the quirt, it's just pleasent to play. I can't really put my finger on anything it does poorly. I don't know that it does anything absolutely right, but I am still shocked at how totally balanced and accurate it is. Instruments really sound much like they should sound. Are they fully fully fleshed-out and harmonically true and accurate, probably not. But their darn good. And the base is shockingly full and rich and quick. It's also well blended with the rest of the frequency range and extends quite well up into the top registers. This is just a $179 delivered to your door amp. I could only imagine how much better a more well-thought-out piece might be. Then again this was designed and voiced by a European company so it may be that it actually competes pretty well with other much more costly units It's just not as powerful and robust and capable of driving larger less efficient loads.
            PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI preamp,
            Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
            Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects.

            Comment


            • #52
              Here is the spec on the chip the amp I am playing utilizes. I have no idea if this is a custom amp module or a copy of a standard design. Anyone know?

              http://www.ti.com/lit/ds/symlink/tpa3118d2.pdf
              PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI preamp,
              Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
              Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects.

              Comment


              • #53

                A few points on this conversation all responded to briefly here.

                1. Distortion is the measure of how much the reproduced signal is compared to the original signal. It does not measure how badly the signal is distorted or what kind of distortion or if other signals are introduced else where in the circuit. Another issue is that the distortion numbers are measured with a simple sine wave while actual use of Audio equipment is very complex waves, closer to a square wave. So while distortion figures may look good, actual performance may not be as good. Try a simple square wave and look at the result on an oscilloscope. You can easily notice the difference. It is very apparent.

                I mention this as the distortion is sometimes pleasant, that is even harmonic, and sometimes not pleasant, that is odd harmonics. The louder harmonic is typically the one that is noticed, however listening fatigue can be another gauge of the distortions present.
                Class D distortion simply extends the signal creating a lot of distortion. So you can see distortion numbers in Class D at the end of the power spectrum typically go up like the corner of a hockey stick. This oversimplifying it but you get the point.

                The typical cause for distortion is the limits of the power supply. This is true of all amplifiers.
                For Class A amplifiers and Tubes (not push pull), operating in the non linear portion is another cause and if not biased in the middle of the curve and operated outside the linear portion, you again get distortion. Class A and tubes tends to cause even harmonic distortion and hence liked much more then even the slightest solid state distortion in Class B or hard clip on the Class A which tends to be odd harmonic distortion.

                Class D distortion is much like a compressed recording. Just full out noise.

                2. Much like any design, designs evolves and improves over the years especially when technology improves and more attention is paid to the design class. Class D with the Gallium Nitride Transistors, now for the first time truly allows Class D to shine above the rest. The biggest issue with prior Class D designs was the technology available. MOSFETS were commonly used and MOSFETS have too much capacitance in its gate/channel and simply could not switch fast enough ( this is not the frequency of the switching but the time it takes to go from off to on or on to off, even at a lot frequency of switching). Since it took time for the MOSFET to go from on to off or from off to on, all Class D designers used to delay the next switch to allow the MOSFET to settle. This was called dead time as no signal(music) was played during this time. Hence it was compared to digital as digital music also has gaps that have to be filled. Hence Class D was incorrectly called digital but it did sound like digital. Designers tried to compensate for this distortion with feedback and bridged circuits. Heavy use of Feedback seem to smooth this over quite well with the recent amps, even with the Merrill Audio VERITAS Monoblocks using the NC1200. What this did was to also remove some detail and speed. Another issue that MOSFET's had due to the parasitic inductance and capacitance was ring and overshoot. Both were terrible and had to be dealt with by slowing down the switching frequency and other tricks. Remember the Mark Levinson at 1MHz switching?

                With the advent and availability of Gallium Nitride(GaN) Transistors, the switching time is no longer a limitation. The Capacitance of the GaN transistor is near zero and hence it can instantaneously( for the required frequency spectrum in the megahetz) switch from on to off or off to on. Hence the dead time with Class D using GaN transistors is zero - which means no distortion. There are many other extrinsic aspects that have to be take care of to keep the parasitics close to zero. So just using the GaN transistor is not enough.

                For the Merrill Audio ELEMENT series of Class D Amplifiers, we have gone a step further because we can. There is no feedback at all, it is an open loop.

                With that, it is safe to say Class D has arrived as the ultimate in high fidelity reproduction. I am sure this will be debated as hotly Blockbuster and Netflix.

                Alan Sircom of HiFi+ stated in the March 2019 issue, "A crucial aspect of the sound is that speed Merrill strives for. This is no small deal, as the (Merrill Audio) Element 118 really shifts up a gear. There are a handful of amplifiers that create a sound as fast and as precise as this, but one of the few that is still in production is DarTZeel. The two (DarTZeel and Merrill Audio) have a lot in common sonically, although the (Merrill Audio) Element 118 is perhaps even more neutral-sounding than the Swiss triumph. This comes across in every piece of music you play, and it comes over quickly too; that two-second piano scale at the start of ‘Misty’ on Donny Hatherway’s Everything is Everything [ATCO] says it all. It’s vibrant, in the room... and what follows is one hell of a voice. The speed of the Merrill means there is no overhang or limits imposed upon his soaring voice. Just those first few bars led to a complete Donny Hatherway tip for a while, and at each point you got a sense of temporal ‘rightness’ that was backed up by an extended and fundamentally accurate presentation. In particular here, although the voice is front and centre, that whirlwind speed means the amplifier is a master at playing horn sections. They are played without any sense of overhang or slowing of what can be a very fast-paced instrument."
                (Words in Bold and in parentesis is added for clarification)

                I am sure in the future there will be more GaN amps however it is still very complex to have zero feedback and zero dead time, and that will be the challenge for those followers.

                3. Tubes have been around for ever. Tube rolling or looking for brands of NOS tubes and hunting for the right tube certainly seems to point to Tubes having a "Sound" which means the fidelity is compromised. That does not mean it is not liked. It is very well liked. As some have even said, is it the search for nostalgia that gets them, to have the sound like they heard when they were young. It is common knowledge that Tubes produces the likable even harmonics which Art Dudley form Stereophile famously wrote is not distortion and that is why he likes it

                Regardless, when measured with a square wave, the difference can clearly be seen. The ultimate goal is neutrality. That is the Audio component should not have a sound in any system that it is in.

                My conclusion and suggestion:
                A simple (still with complexities) way to measure equipment is to plot the output of a square wave from the component. Nyquist claims sampling at 2x frequency to reproduce a clean wave. Well we can see that is only true for a very specific sine wave on a system that is made to reproduce only sine waves.

                Stereophile used to put out measurements of square waves and sine waves from CD players. That was a nice demonstration of how badly the CD's reproduce sine waves and and it did even worse on square waves.


                “In times of change, learners inherit the earth,
                while the learned find themselves beautifully equipped to deal with a world that no longer exists. ”
                Eric Hoffer

                Merrill Audio.

                Comment


                • #54
                  I keep hearing people in other places talking about their class D amplifiers failing and taking out speakers with them at times. They seem to say a Class A or AB amps are much more robust and dont damage associated equipment. I was thinking of using a Class D amp to run the woofers and I'm now thinking that might not be a good idea? Is there anything to what I'm reading?
                  PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI preamp,
                  Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
                  Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects.

                  Comment


                  • #55
                    Originally posted by EdAInWestOC View Post
                    Maybe someone can chime in and help me with something.

                    I don't understand the use of class D in an audiophile class amp. Everything about an amp is about modulating the power supply to produce a carbon copy of the input signal. Introducing switching into the power supply and the output devices sounds like an invitation to introduce non-linear content into the output.

                    The very best traditional amps are all about their power supplies and the ability to supply instantaneous current into a difficult load (the speaker) during a very demanding program source. Adopting a switching approach into this arena certainly introduces efficiency but what are we doing to the output signal?

                    Each time I read about a class D amp, I hear reports about different sounds that these devices introduce. This sounds like an approach that would be welcomed for other amplification purposes but for absolute fidelity it sounds like a wrong turn.

                    I am sure some of these are much better than others but for absolute fidelity I find the approach absurd. When we want efficient amplification class D makes all the sense in the world. When we want absolute fidelity class A is the best approach and I have never heard anyone argue otherwise.

                    The KISS principal still holds true no matter how much someone may argue for some other hi-tech approach. We wandered away from tubes in the 1960s when everybody saw the amazing efficient solid state devices.. Then someone compared a solid state amp to a tubed amp and listened.

                    To be sure the tube amp sounded better than any early transistor amp and that still holds true today. The high end is not about efficiency or compactness, its about fidelity. The old vacuum tube makes music better than sand. The transistor can sound pretty dammed good, now that we have has decades to learn what was right and wrong, but for absolute sound quality the tube is still king.

                    It isn't efficient and wastes lots of power and space but who cares? That isn't what this hobby is all about. And that really irritates a lot of people who do not understand why we all spend so much on such antiquated equipment. We could make music with a smart phone and some bluetooth earbuds. Why do we all insist on such old fashioned stuff?

                    All of the above comes to mind when the subject of class D amps come up. It seems to be another modern device that has great potential. What does it sound like compared to an old-fashioned all class A amp?

                    And that is why we do what we do.

                    Ed
                    If it is helpful (and I am NOT a technically savvy guy) the amp I am thinking of uses a 700KHz switching frequency.

                    If I am not mistaken that means it switches at 700,000 times a second. I tend to think you have no ability to hear that switching.

                    Quite possibly lesser amps at lower frequencies might be affected, but this isn't 700,000 time a minute, but a second.

                    Comment


                    • EdAInWestOC
                      EdAInWestOC commented
                      Editing a comment
                      My question still remains...why do this? Why introduce yet one more variable in the job of reproducing a waveform? It reminds me of the argument about digital audio.

                      As a vocation I do nothing but deal with digital. I have been in the computer industry since 1974, so I do understand what digital can do. All of it doesn't make sense when you are trying to reproduce an analog waveform. Why introduce yet one more thing that can go wrong?

                      Modulating a DC voltage to create a voltage/current source to drive a speaker is difficult enough to do properly. Introducing switching into the picture may be accomplished but I doubt if it is 100% transparent, 100% of the time.

                      The best way to do this is via a class A amplifier. This is the least efficient way to do the job but the most simple and, as it turns out, one of the best sounding ways to do the job.

                      The more variations you add to the job, the more things that can go wrong and the more ways something can sound not 100% natural. I just am at a loss why we would do this if what we are trying to accomplish is the highest fidelity. If we are trying to accomplish greater efficiency then it would be worth looking into. If we are trying to accomplish the best possible fidelity then I would argue why, what are you trying to do?

                      It just sounds misguided.
                      Last edited by EdAInWestOC; 05-09-2019, 07:48 AM.

                  • #56
                    I think class d gets a bad rap at the start. I have heard the mola and the newer hypex version. I also heard the devalues excuse my spelling hope it's close enough for u guys to know lol.
                    Some sound bad some are not so bad in some setups.
                    The bass is there weakness I feel yet some use it just there.
                    They do pop but don't seem to have the info like Myles says.
                    In a well done setup some genre is good , some genre not so good.
                    I think a setup that has less resolution they sound better.
                    At shows it's hard to judge sound as many rooms are just not good enough too.
                    At the ny show there was a room a big name brand.
                    They said there amp was digital. Me being naïve
                    said does the d stand for class d ? He got mad and said
                    no. I thanked him and left shortly after. It was bad lol.
                    I think if someone wants to shop for one do so but make it a trial.


                    speakers cust infinity IRS V , new caps and LPS , magnets etc.
                    mark levivson pre no 26 amps no 33
                    digital three cust servers , win ser 2016 , AO
                    Dacs lampi various

                    Comment


                    • #57
                      As James Bond said, "Never say never". ok you have not said that yet.

                      As Alrainbow says Class D gets a bad rap. Little is understoood about it, the technology was not available - Until now!

                      In terms on Linearity, Class D will be the most linear you can get. Class A depends on the curve of the transistor and only a small portion is linear.

                      This is from an college class and is basic but you get the idea of non-linearity.
                      http://www.physics.csbsju.edu/trace/NPN.CC.html

                      Of course the calculator is complicated but going back to the abacus seems foolish, especially when you can move from the calculator to the computer.

                      EdAInWestOC The reason to do this is there is a better way.
                      Class A was simply the very first class of amplifier designed. It was very simple, now looking back,hence it was the first invention in amplification. It had and still has a lot of flaws. Class B was more efficient and it took a while to lean a few tricks about tun on time to remove this piece of distortion.
                      Class C is used for RF and has a specific frequency
                      Class D was invented next, hence the Class D term and nothing to do with Digital.

                      Benefits of Class D - fast, very efficient, thoereticallly instant power on (better immediacy) and load invariant. This is just the amplification stage.

                      how far has Class D come? Very far in the last few years.

                      So note my new Class D amp - have zero feedback! There is no need to take care of distortion on the output. That how good and clean it is.

                      Having Zero Feedbak also provides more details.

                      Also take a listen to the ELEMENT Series of Amplifiers from my company ( I cannot speak for other companies and/or should not), and 2 separate reviewers on 2 difference continents put my amps in the Class of DartZeel and one said it is even better (HiFi Plus).

                      The difference between this and the previous Class D? Several items
                      1. The availability of Gallium Nitride (GaN) transistors now allows Class D to switch instantly on and off without overshoot, ring and zero dead time. This was the biggest issues the old MOSFETS had. There was just too much parasitic capacitance in the channel/gate to turn of/on in the time needed. Along with the settling time produced ring and overshoot. Many tired to cure this with Feedback, and some heavy feedback.

                      2. PCBs can now easily be built with technology that removes reflections and any other artifiacts. this was brought about by the digital age or the age of high speed computing, and RF technologies from the Gigahertz.

                      3. New packaging for GaN Transistors that was developed for the computers and RF.

                      Other items that have been around and continue to improve are non inductive capacitors, machine loading PCB's assembly ( need to install chips as small as 1mm or 0.04 inch in length) and many other sophisticated techniques that are common for computing and RF boards.

                      Collectively Class D will start to pop up everywhere.

                      Just in contrast - the new ELEMENT series of amps from Merrill Audio are at least an order of magnitude better in sound quality then the old VERITAS Monoblocks.

                      That is how far Class D has come - has has more to go.


                      One of the beauties of today's technology is that measurements are easier to make, which means easier to understand what is needed and then get the right tools applied.

                      Hence out with the Horse and buggy (unless you want a ride around Central Park with your significant other) and in with the Tesla.

                      For the reviews look up Positive-Feedback.com, HiFi Plus (print and soon to be online), Soundstage is coming up, PartTimeAudiophile is coming up and of course the great Myles Astor has a pair in his apartment for review also. You can google Merrill Audio GaN to see what else is out there. A few early folks did do comparisons and posted the result on forums.

                      Better yet - bring your best and favorite amp to compare them to the Merrill Audio ELEMENT series at any location to hear for yourself how much better Class D now is then any other technology. A bold statement that you should definitely take me up on. Class D is still being burnt at the stake but soon to be mainstream.

                      Cheers
                      Merrill Audio.

                      Comment


                      • EdAInWestOC
                        EdAInWestOC commented
                        Editing a comment
                        I understand your argument and I support better things but in the effort to make things better with class D, there are lots of pitfalls. My point is that there is a better approach to something by keeping the job simple.

                        Yes, Class-A is inefficient and simple. But is sounds really good and that is why we are in this hobby. We are not audiophiles because we want more efficient amplification. Personally I could not care less about the efficiency. I want better sound and damm the efficiency. That is not the point.

                        And that is what I have been saying. Make a better sounding amp and many audiophiles will buy it. Maybe I don't represent the majority but I do not care about whether the amp is based on class-xyz, whether its based on SS or tubes, or whether it makes our clothes whiter. It is the sound and producing the sound with more convoluted means is a step in the wrong direction as far as I am concerned.

                        I have been in the hobby for 5 decades now and the best sound has always followed the simplest circuitry. The more parts you add to a circuit, the more chances the sound will suffer. There may be exceptions but that prior statement has stood the test of time.

                        I hope that someone does produce a better amp. I will buy it if that is the case. Until then I'll wait for a better and simpler device.

                    • #58
                      Ua100k. How does your amps fair On a load like my speakers ?
                      Nominal 4 ohms but dips to 1.7 for the Mids
                      it's barely at 4 and majority below it.
                      Power needs is hard to calculate if we count the needed
                      dynamic headroom
                      amps of the past all clipped and were rated at 400 watts into 4 ohms
                      i had an old 4004mkii I modded and increased the caps to 4/36k from 18k.
                      It was much improved but clipped as it played at even a normal volume.
                      What I have now is absurd to compare to.
                      What are they rated at and how do they sound when clipping
                      the bass towers have they own 2k watt each below 120 hertz or so maybe higher
                      interested .
                      speakers cust infinity IRS V , new caps and LPS , magnets etc.
                      mark levivson pre no 26 amps no 33
                      digital three cust servers , win ser 2016 , AO
                      Dacs lampi various

                      Comment


                      • #59
                        I brought home a pair of these IRS Beta Subwoofers, and their subwoofer controller. Note the full-size hand cart strapped on to one, to bring it into my audio room.

                        IRS Beta SW by c f, on Flickr

                        These are large subwoofer towers with a sophisticated controller comparing an accelerometer output from each tower back to its input signal. I quickly needed a decent bass amplifier! I first tried a Rotel amp that was well reviewed and the bass sounded soft and the overload lights were always flickering. They are 4 ohm bass towers with 12 inch graphite woofers and really pretty efficient.

                        Well, I grabbed a $150 IcePower Stereo Module rated 125 wpc into 4 ohms (Class D), and mounted it in an aluminum case with proper connectors, and it has sounded GREAT ever since! These subwoofers blend nicely with my main speakers/amp, usually a pair of highly modified stand mounted Sonus Fabers driven Bi-Wired by an Ayre V3 (traditional) amp.

                        In addition to the great bass I am impressed at how linear the IcePower amp module is, and how cool it runs. Certainly a great bass amp! Class D simply means PWM (Pulse Width Modulation) at a rate well higher than the audio band with filtering, and its linearity is superb. Check out the tiny size, cool running, and energy efficiency! Fear not...

                        IcePower handfull by c f, on Flickr
                        Last edited by chrisfromri; 05-17-2019, 02:08 PM.

                        Comment


                        • #60
                          Originally posted by ua100k View Post


                          With the advent and availability of Gallium Nitride(GaN) Transistors, the switching time is no longer a limitation. The Capacitance of the GaN transistor is near zero and hence it can instantaneously( for the required frequency spectrum in the megahetz) switch from on to off or off to on. Hence the dead time with Class D using GaN transistors is zero - which means no distortion.
                          On its face, this statement is false. GaNs have significant capacitance (although in some important ways, far less than MOSFETs), and shoot-through currents will exist despite the much higher switching capacity of GaNs. So unless dead time is employed, shoot through currents will cause heating of the output section. Deadtime is present in almost any design unless very special steps are taken to avoid it.

                          With regards to distortion, it is a simple fact that with class D, distortion is not a function of the output section in a direct manner as in traditional amps. But its incorrect to say that if there is no dead time that there is no distortion! The encoding scheme has to be perfect otherwise it also contributes to noise and distortion. And since nothing is perfect, this happens.

                          Comment

                          Working...
                          X