[music_man]

I noticed Transports always have switching PSU. That should be better for the task. Due to the Audio Many CD players have linear, a few switching depending on the Engineers.

Am I correct that this is why They do not put linear psu's in Transports? I would doubt it is to save money on 5-6 figure transports. Even a CD player used as a Transport I would gather you are not using the linear section. As those as well are driven by switching psu's. On the Motor's,pickup etc. Linear psus are most often employed for sound characteristics. Analog sections. Digital is best served by a switch mode psu.

I just figured this is why you see this in a transport or cd player and they are not saving money. In fact I believe they are doing what performs best.

Obviously I know about this stuff. I was just wondering why you almost "never" see linear psu driving the motor,pickup, digital output. I suppose it is because it just does not offer the best sound.

Then why do many high end DAC's have linear psu's? That is what I do not get. Unless I am missing a tiny E core driving the digital hidden somewhere. I would gather that is the case. Linear often performs best on analog but switching on digital AFAIK. I am an EE but I never designed a CD player. I was just wondering if anyone else versed in this wishes to elaborate.

Thanks

 

[music_man]

I will answer my own question. you knew I knew this which is why no one responded lol.

Switchmode psu is on almost any digital circuit. If you see a torroid in a cd player, there will also be a often small E-core running the digital. The linear side is on the analog section. A few companies AYRE, Linn etc use switchmode on analog and digital. A different approach but if well implemented can have lower noise floor than linear supplies. What remains true is that properly implemented digital topology will almost always be driven by a switchmode psu. For most companies a linear psu proves better on analog sections. A small few companies can pull off a better switchmode psu on analog. As for the DAC's it is the same thing. Almost always there is a switchmode PCB running the digital. this is because the harmonic falls well below the oscillation of the digital implementation. The linear has more noise to begin with but is on the flipside at a higher bandwidth than the analog section. thus the reason for such implementation of switching and linear circuits within the digital/analog domain. Being able to pull off a properly fully switched design has some benefits but is only seen by a very few companies. Unless you are talking about $150 CD players in which case the whole thing is also switched and they sound terrible. That is contrary to the proper implementation of such devices. Albeit, which are few.

Pretty much what I said above. I guess I posted an answer and not a question