CurtPalme.com Home Theater Forum

[dturco]

Register to remove this ad. It's free!

I would like to know what is it, that is the final stage in a Bluray player. The OPPO 95 or 93 Nuforce to be exact. I do not know what to search for. Is it the Dac or Op-amp that makes the sound I end up hearing?

What creates the Sonic signature? The warm sound or or harsh characteristics?

Please no theory papers. Just what is which one doing.

Here is what I think is going on. The DAC [Digital to analog converters] Convert the 1's and 0's to a pulse wave that the Op Amp [Operational Amplifier] receives and increases that wave to be output. Which in the case of the oppo could be the last stage before amplification.. a whole different item right?

That's all?


Of course not that is why I am asking.

[Curt Palme]

A DAC is just as you say, it's a format converter, much like the Fury. It converts digital 1s and 0s to an analog output.

An op amp is just an amplifier. Analog in, analog out.

[Curt Palme]

A DAC is just as you say, it's a format converter, much like the Fury. It converts digital 1s and 0s to an analog output.

An op amp is just an amplifier. Analog in, analog out.

[dturco]

[beun]

If you want to believe the audiofools everything colors the sound, from power supply cords to wooden pyramids on top of your player.

But lets keep this technical, both the DAC and the opamp can actually color the sound and it depends on the choice of component and the way how it is used. For example sigma-delta DAC's exhibit a very large amount of out of band high frequency noise. A perfectly good opamp that doesn't have enough bandwidth and slew-rate to handle that will muddy and distort the sound. In an application where that large amount of high frequency energy is not present that opamp operates perfectly and maybe even better than the high speed/high slewrate opamp.

I can go on forever, the topic is wide ranging and the interactions usually very subtle.

[Curt Palme]

All or none of the above.

I'm not a big believer in one unit sounding radically different than another, although I did notice some difference between a $250 CD player, and the same transport being played through a $1200 external DAC box. I A/Bed the two outputs, and yes, the $1200 DAC sounded different.

Now, was it the DAC chip specifically, the op amp(s), the power supply or the circuit design, I have no idea. there's raging debates about this all over the 'net, to me within the same specs and approx price range, you're not going to find a lot of sonic differences between hardware. <flame suit on!> The exception though is speakers, as they are changing electrical to mechanical energy, and because of that, there are even measurable differences between identical speakers.

That's why I don't put too much emphasis on the electronics and what kind of chips are used, the speakers and listening environment vary too much over what the electronics change.

I'm totally open to debate on this though.

[Curt Palme]

All or none of the above.

I'm not a big believer in one unit sounding radically different than another, although I did notice some difference between a $250 CD player, and the same transport being played through a $1200 external DAC box. I A/Bed the two outputs, and yes, the $1200 DAC sounded different.

Now, was it the DAC chip specifically, the op amp(s), the power supply or the circuit design, I have no idea. there's raging debates about this all over the 'net, to me within the same specs and approx price range, you're not going to find a lot of sonic differences between hardware. <flame suit on!> The exception though is speakers, as they are changing electrical to mechanical energy, and because of that, there are even measurable differences between identical speakers.

That's why I don't put too much emphasis on the electronics and what kind of chips are used, the speakers and listening environment vary too much over what the electronics change.

I'm totally open to debate on this though.

[garyfritz]

Digital sound is ""perfect."" (Or at least as perfect as the digitized approximation can be.) 1's are always 1's, and 0's are always 0's, unless you have a defective unit.

Unfortunately we can't listen to digital. We need analog signals for our ears. As soon as you get into the analog domain, the quality of your design can affect the resulting sound. That includes the A part of the DAC, and everything else between the DAC and your ears, including the op-amp, all surrounding output circuitry in the player, the signal path through your amp to your speakers, even your room. Even your ears if your hearing is less than perfect.

Now if you compare a BluRay player through that signal chain with *another* source through the same signal chain, you can be reasonably sure that any differences you hear are due to the player. If the BluRay player sounds muddy or whatever and the other source doesn't, it's probably the BR player. But there's no way to know what PART of the BR player is doing it, without opening it up and doing some pretty serious signal analysis.

[dturco]

I was afraid of this. So the real answer is yes some of the Dacs and some of the Op-amps and some of the circuit design "colors" the sound.

For what it's worth I can hear a difference between each player that I have put into my system. No the differences are not huge, but some do sound more pleasing than others.

Back to square one. Buy it, listen to it, like it, or, not like it.

[ecrabb]

So, I take it you were using the analog outputs on the Oppo, Dave...

SC

[dturco]

[MikeEby]

The BDP-93 uses a Cirrus CS4382A DAC, and the BPD-95 uses SABRE32 ES9018 32 Bit DAC's so the two units will most likely sound different.

http://www.cirrus.com/en/pubs/proBulletin/cs4362pb-1.pdf


http://www.esstech.com/PDF/Sabre32%20DAC%20PF%20100622.pdf

Mike

[dturco]

[Tom.W]

[Curt Palme]

Yes you can argue that the chips sound different, but also keep in mind that each manufacturer uses different parts and circuits around the DAC or the op amp, so you can't pinpoint the difference in sound just on each chip itself.

I commented to an engineer a while back about how every pro audio manufacturer has a DSP unit, and I asked how does each manufacturer have the R&D time to come up with their own chip? He laughed and said that the DSP chips are only made by select few manufacturers, the pro audio companies just take those and build their own peripheral stuff and software around it.

[Curt Palme]

Yes you can argue that the chips sound different, but also keep in mind that each manufacturer uses different parts and circuits around the DAC or the op amp, so you can't pinpoint the difference in sound just on each chip itself.

I commented to an engineer a while back about how every pro audio manufacturer has a DSP unit, and I asked how does each manufacturer have the R&D time to come up with their own chip? He laughed and said that the DSP chips are only made by select few manufacturers, the pro audio companies just take those and build their own peripheral stuff and software around it.

[MikeEby]

[dvh99]

on diyaudio there was a big topic on i think the sabre dac, it must be a killer dac from what i heard of it but in the end its of course the choice of components and the circuit of course.
too many variables

dunno if the sabre dac you mentioned is discussed on diyaudio though.
there are a few different versions.