AFAIK...D is equivalent to AB in terms of sound.
I've only heard one hi-fi class D amp. It was massive.
Your 'badass' AB amps ?It was massive because the builder knew it had to be to impress you. That's the only real reason.
All that needs to be big on D amps is the power supply. The primary chip needs a relatively small heat sink. Nothing much else.
I'll compare a class D amp to my (badass) AB amps when I find a company that builds something quality minus the bullshit. In other words, better than the lie-laden Chinese built trash, minus the 80 lbd of CNC aluminum the "high end" companies strap to them to justify all the extra zeros at their price point. Quality chip, clean power, well designed but 'frugally' built chassis.
If I don't see something in the next few months I may look up provide it to the market myself. This isn't hard... Or rather, it doesn't have to be.
Your 'badass' AB amps ?
What do you have besides the Nak PA-7AII ? The Nak is a badass amp for sure, but you have others ?
The class D amp I'm referring to held it's own against a Parasound HCA-3500.
Looks like you could replace the caps...what else could possibly wear out ?At least your AB amp is likely to have through-hole components and has already stood the test of time and can be repaired relatively easily. Try that with a Class D. They are disposable unless you have serious SMD reworking capability and bespoke parts.
You're really comparing vintage to modern construction techniques, not amplifier circuit topologies. A modern mass-produced class AB amp is just as likely to be SMD construction as a modern mass-produced class D amp, and both will be equally disposable and/or annoying to fix.At least your AB amp is likely to have through-hole components and has already stood the test of time and can be repaired relatively easily. Try that with a Class D. They are disposable unless you have serious SMD reworking capability and bespoke parts.
You're really comparing vintage to modern construction techniques, not amplifier circuit topologies.
I would love to see another supplier out there that did what Emotiva did, but not change as Emo did. Emotiva, once they got up and running good changed their focus to AV stuff. If you have the ability to build and produce a quality Amp at a great price, you will make money. What I found was as Emotiva moved out of audio and into AV, a quality, well built, and most of all, long lasting amp became very expensive. Hence my signature of Pass Labs. I bought it used for 25% of new price, so I feel I did well. And yes, you can have my clas A/AB amp from my cold dead fingers.It was massive because the builder knew it had to be to impress you. That's the only real reason.
All that needs to be big on D amps is the power supply. The primary chip needs a relatively small heat sink. Nothing much else.
I'll compare a class D amp to my (badass) AB amps when I find a company that builds something quality minus the bullshit. In other words, better than the lie-laden Chinese built trash, minus the 80 lbd of CNC aluminum the "high end" companies strap to them to justify all the extra zeros at their price point. Quality chip, clean power, well designed but 'frugally' built chassis.
If I don't see something in the next few months I may look to provide it to the market myself. This isn't hard... Or rather, it doesn't have to be.
Even the power supply doesn't need to be physically large. With proper shielding, switch-mode power supplies can be noise and interference free and supply kilowatts of energy in a lightweight package.All that needs to be big on D amps is the power supply.
True, because a class D topology is highly efficient. 90% of the energy that comes in through the power cord goes out through the speakers as sound, so only 10% of the input energy needs to be dissipated as heat. Compare that to AB designs, where at best approximately 25% of the input energy must be dissipated as heat.The primary chip needs a relatively small heat sink. Nothing much else.
Sure. See my post above yours. I linked to this: http://www.studio-rts-ing-rampin.it/ampdiva/ampdivapdfdepot/ampdivawhitepaper1en.pdfDoes anyone know if class D is even possible for a tube amp design?
Well, no, not really. Ca. 90% of the power drawn by the Class D amp from the "grid" is indeed presented to the loudspeakers - but virtually all loudspeakers still have efficiencies of a couple percent. Most of the power delivered to the loudspeaker is wasted - as heat. The acoustic power output of a loudspeaker is fairly meager --although one watt of acoustic power corresponds to pretty impressive SPL.True, because a class D topology is highly efficient. 90% of the energy that comes in through the power cord goes out through the speakers as sound, so only 10% of the input energy needs to be dissipated as heat. Compare that to AB designs, where at best approximately 25% of the input energy must be dissipated as heat.
Most speakers are actually very inefficient; only about 1% of the electrical energy sent by an amplifier to a typical home loudspeaker is converted to acoustic energy. The remainder is converted to heat, mostly in the voice coil and magnet assembly. The main reason for this is the difficulty of achieving proper impedance matching between the acoustic impedance of the drive unit and that of the air into which it is radiating. The efficiency of loudspeaker drivers varies with frequency as well. For instance, the output of a woofer driver decreases as the input frequency decreases.
source: http://www.diyaudio.com/forums/multi-way/3973-klipsch-efficiency.html#post2808973Be aware that there is a distinction between efficiency and sensitivity. The first is acoustic watts out for acoustic watts in and the other is SPL on axis for a given voltage. They can be converted but only if you know directivity or polar pattern.
1 acoustic watt is 109dB in full space at 1m. If your radiation is hemispheric then this becomes 112dB at 1 m for half space radiation. Most units are even more directional so you need a number for d.i. (directivity index in dB).
With a typical high frequency d.i. of 10dB then a 50% efficient horn (the maximum possible) would be 109 + 10 - 3 = 116.
Scale from there.
David S.
This is true regardless of amplifier topology.Well, no, not really. Ca. 90% of the power drawn by the Class D amp from the "grid" is indeed presented to the loudspeakers - but virtually all loudspeakers still have efficiencies of a couple percent. Most of the power delivered to the loudspeaker is wasted - as heat. The acoustic power output of a loudspeaker is fairly meager --although one watt of acoustic power corresponds to pretty impressive SPL.