Atma-Sphere Class D… Amazing

@twoleftears

Indeed, those marketing Hypex, Purifi, and several other class d amps using the modules of others can "tune" the sound through the input buffer op amp choices

@kuribo If they can ’tune’ the sound just by changing opamps they are either using really terrible opamps or don’t know what they are doing!

We’ve had the idea of a SMPS meant for the amp for a couple of years. That’s not a trivial design project although its certainly an one than the module itself was! Of course we looked at available SMPSs including those meant for audio, but again we ran into not only performance (which impinges the sound and performance of the module) and protection issues but also cost issues! If we make it ourselves then we solve three problems at the same time. In the meantime the toroidal supply is less expensive, works right and we have the right protection although we need a more expensive chassis to support it. IME though, that chassis helps with the mancave/WAF issue. In my case this means that I don’t have to have a mancave to run my stereo (although I do have to be careful about cargo shorts); it can be in the living room without inciting ire. Ya picks ya poison I suppose.

I should also mention we're concerned about noise. For example Bruno uses a current pump to create lower voltages for opamps and the like. We found that is noisier than using a more expensive supply for the same task. As a result the amp puts less noise on the AC line than most tube amps.

@atmasphere , I agree with that whenever SQ can be affected, but making thick chasis just to  protect the amp during the shipping seems to me unreasonable - just pack it well! 

I think what @kuribo says is very reasonable, and this is not something in  what he can have some personal interest. If you manage to lower the price of your product (without sacrificing SQ) , given its good or even outstanding sonic characteristics, your product will become much more competitive and you will be able to sell much more of them having higher overall gain, talking in pragmatic terms, unless you wish to have a product for a very selected amount of people. 

If they can ’tune’ the sound just by changing opamps they are either using really terrible opamps or don’t know what they are doing!

These are the claims of customers- they prefer the "sound" of certain op amps over others, not mine!

I would think that a module with a high PSRR would reduce any deleterious effects of the smps, at least that is what Bruno claims with his modules. Based on their measurements, it seems to be true.