GaN-based Class D power amps

ricevs

George,

If voodoo means listening to things and using the best sounding things then certainly I am a super voodoo lover.

EG: An efficient 98db 6-8ohm speaker. But with 3ohm impedance dip, and a -60 phase angle at 100-200hz, everywhere else it’s pretty flat at 6 to 8 ohms, that’s why the manufacturer calls them a 6ohm speaker.
Any tube amp will sound thin and lifeless because it can’t drive those speakers properly between 100-200hz. (a 3ohm load with -60 phase angle will have an EPDR that looks to the amp like it’s driving 1-2 ohms!!!) And if you don’t know what EPDR means then I suggest you look it up, there’s a few pages "technical" explanation in Stereophile.
https://www.stereophile.com/content/heavy-load-how-loudspeakers-torture-amplifiers-page-2

Yes, really bad measurements usually correlate to poor sound.  However, most all Class D amps measure fine (low distortion, high damping factor).  This is my point.  You were asking the person whether they were going to measure the amps (all Class D).  This is what I was responding to.  Almost all Class D amps measure pretty darn good.  The Ncore amps measure better than most but are now taking a sonic back seat to the new IceEdge modules that measure great, but not as great as Ncore.  Another words, the measurements have nothing to do with the sound in this case......in fact, the cheaper Ncore NC400 measures slightly better than the expensive NC1200 but everyone says the 1200 sounds better.

Some tube and solid state amps and some zero feedback amps measure poorly......and usually this has a sonic result.  However, even some not so great measuring amps (Dartzeel and DAgostino, for instance) have a reputation for great sound in many ways. 

The new Relentless amp from Dan does away with the not so great measurements.  He uses over one hundred output devices to get low output impedance and super matches the front end so he can achieve low distortion numbers without feedback.  I am sure it sounds outrageous.....at a quarter of a million dollars, it should.  Dan makes his own output binding posts out of big hunks of brass......brass?!?!?!?!  Brass is very sonically lossy.  Why not Tellurium copper, or pure copper or PCOCC copper or silver or whatever.....but brass?  You pay $250,000 for amps and they have veiled output connectors.....yikes!  However, even the input connectors are $5 brass Neutrik connectors.  How much better would the amp sound with my binding post bypass system and some better sounding xlr input jacks?.......noticeably!.....and it would not measure any different.

All the tweaks and mods I have done to the IceEdge module do not make it measure any different......but the aural distortion has gone down tons.  You must listen.  Measurements can tell you very little of the actual sound.  Two amps that measure the same can sound worlds different.....so the measurements have no correlation to the sound.......they don't tell you how it sounds! 

Just changing the fuse, footers, shelving and power cord on an amp can give incredibly different sound.....none of which shows up on a distortion test.  This is just the beginning....there are tons of things one can do to lower the aural distortion in an amp that have nothing to do with measurements.....this is how it always was and always will be. 

Measurements are fine.  It is good to have good measurements (I certainly prefer better measurements)......but it does not tell you how it sounds.

You cannot read the distortion measurements posted on some Stereophile review and know how an amp will sound.  All amps with decent specs will sound different.  You could have an amp with really high damping factor and it sounds not so great in the bass.  You could have an amp with really wide bandwidth and the highs are not worth writing home about.  Every single thing in an amp will add its sound.  One super bad resistor or whatever and BAM!.....there goes the transparency.  Here is an interesting fact.  Heatsinks ring.....yup.  If you take your fingernail and scape it across your heatsinks and if they ring then you are adding that sound to the amp.  Many people have tried damping their heatsinks on my suggestion and all of them are amazed at the sonic benefit......less "transistor sound".....he he....or should we say less "ringing heatsink sound".  Again.....not measureable.....but certainly audible.

I am not against measurements.  They can show you if you have a serious problem.......and some distortion artifacts (predominance of even or odd order, for instance) can be audible.  But obsessing about measurements?  Not in this house!  I want goosebumps.......I don't listen to a distortion meter!

I am not against measurements.

But obsessing about measurements?

I don't listen to a distortion meter!

And what have you to say? Come on, you just like to be right and argue and have the last word. I try to inform. I think my post is very informative. I think it will help people. There is probably someone right now damping their heatsinks and getting better sound.  Will your post help people?

There is probably someone right now damping their heatsinks and getting better sound.