[eyeteeth]

http://www.psaudio.com/products/digi...i_overview.asp

Sorry I'm not a technical type but I know many here are very well versed on the technical front. And I know who ever is making something will say their approach is best at that price.

Is PS Audio correct or just totally BS-ing? I know they always present their latest as the greatest, which is OK I guess...

Here is one example of their opinion concerning their DAC.

"99% of every DAC on the planet uses an op-amp to convert the output of the DAC to a voltage. We learned years ago that this is the worst thing you can do for the sound, because op-amps all have two major problems when used for this function: feedback and speed issues.

Without getting too technical, the greatest opportunity for a bright and edgy “digital” sound is caused by op-amp based current to voltage converters (IV converters) because the high speed of the DAC’s output causes transient or slewing induced distortion in the op-amps (SID)."

 

[Garbz]

Nope. It is just their way of justifying their design approach. That is not to say that there is anything wrong with it. I am about to try an experiment by replaceing the opamp I/V stage on my DAC with the discrete Passlabs D1. But in reality feedback is usually a good thing, and opamps are insanely fast these days, and very high end players use opamps in the I/V stage, like the NAIM CDplayers which some would agree are more analogue sounding then... well analogue

So what you are reading is marketing. This is not really an indication of whether it is a good product or not, which it well may be.

 

[eyeteeth]

Thanks Garbz, I had to ask.
99% being wrong is hard to swallow. Yeah it might be a very nice sounding unit. It's probably like all other PS Audio items in being very good within it's price range, and with more features than their competition but not a threat to those at the next level. They sure do have a $995 theme going on lately.

 

[Jon L]

The PS DAC probably sounds very good, and I like the idea of their discrete fet output stage, but that page is just focusing on a few points and making a Huge deal out of them.

For example, they keep emphasizing how the PCM1798 DAC chip they are using are state of the art 24/192 DAC chips, but basically any recent DAC chips are 24/192 capable these days, from Crystal, Analogue Devices, AKM, etc.

I would also point out that PCM1798 is a much cheaper, poor man's PCM1794, which has better current output and digital filtering.

PS audio is also boasting 192kHz asynchronous upsampling via TI SRC4192 chip, but really, who doesn't these days, and... so what? I'd much rather they drop upsampling and lower the price or at least make it defeatable, which it isn't.

They also "decided to add a high end USB computer interface," but what makes their USB interface "high end"? From their description, the USB is simply converted to common spdif and fed into the spdif receiver chip just like any other "USB Dac," high end or not.

I don't know... That page really seems to have been written by an advertising firm to me, but the proof will be in first-hand listening as far as I'm concerned.

 

[Jahn]

so the PSAudio DAC has a passive output stage? well whaddya know, my modded DAC-ah also has the chips taken out of there - we're even!

 

[granodemostasa]

Quote:

Originally Posted by Jahn so the PSAudio DAC has a passive output stage? well whaddya know, my modded DAC-ah also has the chips taken out of there - we're even!

so does my 368 dollar (total) Ori modded zhaolu dac...

 

[RogerWilco]

Quote:

Originally Posted by granodemostasa so does my 368 dollar (total) Ori modded zhaolu dac...

 

[Samgotit]

Quote:

Originally Posted by Jahn so the PSAudio DAC has a passive output stage? well whaddya know, my modded DAC-ah also has the chips taken out of there - we're even!

But it uses the CS8414 receiver.

 

[Jahn]

Quote:

Originally Posted by Samgotit But it uses the CS8414 receiver.

shh that's a Trade Secret! (tm)

 

[eyeteeth]

Quote:

Originally Posted by eyeteeth Sorry I'm not a technical type but I know many here are very well versed on the technical front.

Voila!

Quote:

Originally Posted by Jon L For example, they keep emphasizing how the PCM1798 DAC chip they are using are state of the art 24/192 DAC chips, but basically any recent DAC chips are 24/192 capable these days, from Crystal, Analogue Devices, AKM, etc. I would also point out that PCM1798 is a much cheaper, poor man's PCM1794, which has better current output and digital filtering. PS audio is also boasting 192kHz asynchronous upsampling via TI SRC4192 chip, but really, who doesn't these days, and... so what? I'd much rather they drop upsampling and lower the price or at least make it defeatable, which it isn't. They also "decided to add a high end USB computer interface," but what makes their USB interface "high end"? From their description, the USB is simply converted to common spdif and fed into the spdif receiver chip just like any other "USB Dac," high end or not.

See, now that's what I was expecting. The technocrats to step in and put it all into perspective.

 

[Edwood]

Meh. No AES/EBU digital input.

At least it has balanced outputs.

-Ed

 

[Pars]

Quote:

Originally Posted by Jahn so the PSAudio DAC has a passive output stage? well whaddya know, my modded DAC-ah also has the chips taken out of there - we're even!

A "discrete fet output stage" isn't exactly passive...

I liked this one:
"Many CD players and DVD players have built in DAC’s, but these are rarely as good as the best outboard DAC’s."

DUH! Built-in DACs? Whooda thunk it?

PS may make some good products (don't know, I don't own any), but they are very long on hype in their marketing literature. And I do recall hearing about big problems with their amps a decade ago.

 

[Sean H]

Quote:

Originally Posted by Jahn so the PSAudio DAC has a passive output stage? well whaddya know, my modded DAC-ah also has the chips taken out of there - we're even!

I'm confused on what you are saying here too, Jahn. It's got a discrete, but active, output stage.

While the DAC-AH is filterless I believe it has an opamp output stage if I am not mistaken.

 

[Jahn]

I love mods.

"On bypassing the opamp Supra says:
" It's quite easy- I just cut the link to pin 3 of the opamp. There's some spare holes to connect a pair of 220uF Bi Polar Blackgates in Super E style from the output of the DAC (after the 270 ohm I/V resistor) direct to the output socket. Disconnect the wires from the opamp to the output socket, put a 100K resistor across output socket."

Read from Post #5 on! Go go Passive Output! Pics of the mods too!

Lan and I talked at length about the right caps for me, and the ones we put in there (uh, I forget which ones) have a nice deep bass without getting muddy at all. Folks at the NYC meet had a chance to listen to it feeding both a dynamic and electrostatic rig and seemed to like it!

 

[00940]

Quote:

Originally Posted by Edwood Meh. No AES/EBU digital input.

Why would you want AES inputs ? BNC is the way to go.