CLASS D MONO AMPS buy ATMASPHERE MUSIC SYSTEMS

I love my tube OTL to death (not an Atmasphere but from a highly respected design engineer) so if Atmasphere can engineer a Class D that sounds as good or better than a quality tube OTL, that would be AMAZING!

@ltmandella maybe we can get @atmasphere to opine on whether (or how) one could bi-amp the class-D on the bottom (woofer) with your tube gear on MR/Tweeter?
(It is a fantasy of mine at least,)

I have heard many great things about Ralph’s gear.

There also seems to others doing some great work based upon those Class-D systems..,. So hopefully the high end market can allow for a few people doing bespoke gear to exist in respective geographic areas.

Are they all basing it off of the standard “Bruno parts”?
(with their respective additions and experience.)

@ricevs thans for the link - I did not find class-D yesterday.

@kuribo I don’t think he is competing with Purifi.
I was thinking that his amps are all current amps, but the specs suggest a voltage amp.
All of his other amps are low feedback design, but this one is 35dB of feedback gain.

I am not sure what Hypex and purifi are in terms of feedback gain.

The frequency response is load invariant within 1/10db from 20-20KHz, with 0 degrees phase shift at 20Hz and less than 1 degree at 20KHz. The invariance due to the output impedance being a few milliOhms, the low phase shift due to the feedback value, which allows the amp to correct for phase shift at the bandwidth extremes.

THD from 20Hz- 20KHz  is < 0.1% at full power (200 W into 4 Ohms) and about 0.005% at 1 watt. We think it might be lower but finding a decent filter to knock out the residual has been tricky during the pandemic. We  found one about a week ago and are interested to see how things differ once its integrated into our test setup. The distortion is lower into 16 Ohms.

The switching frequency is just shy of 500KHz, depending on load. The input is entirely direct-coupled.

The filter I mentioned is an Audio Precision device and is used to knock out the residual to prevent it messing with the distortion analysis. If I got this right its 8th order(!) and puts the residual down about 60dB... This is why we've not posted any more distortion data since the residual throws the readings off.

I understand amp pretty at the freshman college level. And I appreciate the new designs and designers bringing new stuff to market.

But I really appreciate venerable designers, like yourself, bringing their expertise to bear on these things.

[/scratching the chin(s) and watching]

Would the dead time be more like, or analogous to, crossover distortion, slew rate distortion, or neither?

Class D is about the needs for addressing increasing demand on our collective electrical supply. 

I may not be the most woke person one the planet, but if one thinks that the 2 channel hifi arena is where much energy is going, then they need to provide some proof and facts to convince me.

Home theatre maybe a small dent.

The cellphone and portable electronics is where the brunt of class-D efforts are headed for reducing power draw.

We can, but we're holding it to a rather high standard: At present, the amp can sit at full power with a sine wave input all day long- something you simply can't do with a conventional solid state amp. We're looking into how far we can push that.

Cosine wave? 😎

after my dealer in NH gets a pair in and gets them broken-in.

@atmasphere do they need break-in?
And if so, then how much?

Do they benefit from power conditioners and power cords?
Or are they as good as they can be out of the box?

Its able to reject a fair amount of AC power line problems. A nice power cord if helpful if you push the amp hard. Its only going to draw serious power when its making power (true of all class D amps)- that's where a nice power cord will help. We've got no feedback on the use of power cords with the amp at this point, AFAIK everyone is using the stock cord.

I am not surprised… @atmasphere 
I have heard only great things about your amps.

I suspect that I would be better off upgrading to them, than I would be to start considering a power cord on an amp that may not have be well designed.