Does a DAC need a pre-amp

[mansr]

13 minutes ago, esldude said:

For people with multiple sources some of which are analog one of the best things they could do is have a DAC/preamp, and combine it with a quality ADC for analog inputs.  This can do a much better job of transparently buffering and isolating source components from the power amp input.

And you can apply DSP room correction to all sources.

[mansr]

6 minutes ago, pkane2001 said:

Wow, what are you doing on a Computer Audiophile forum then?

Telling people their gear sucks, mostly.

[mansr]

9 minutes ago, beerandmusic said:

both gutb and speedracer both always talk like if we don't have what they have, then everything else is garbage...i may ask "simplistic questions", but i never pass off their garbage posts...they are so full of themselves, and i wouldn't want either of their systems if i had their same budget....

Speed Racer is ok. GUTB is a joke.

[mansr]

1 minute ago, zackthedog said:

Okay, I have to take issue there.  The GE 6SN7GTA/B from c. 1950-65 is an extremely well-made tube,

The Mayflower was a well-made ship. I still prefer a Boeing 787.

[mansr]

1 minute ago, Speed Racer said:

Not true. I don't care if you have what I have. Heck, there is a lot better stuff out there than what I have. I just can't afford it.

There's a lot of stuff out there I can't afford. Not sure it's always better than what I've got.

[mansr]

5 minutes ago, Speed Racer said:

tubes from 40's made by Sylvania,

The best tubes are from Transylvania.

[mansr]

2 minutes ago, GUTB said:

Were you the one who wouldn’t list his equipment because you were afraid of it being ridiculed?

I don't consider my equipment relevant to the discussions here.

[mansr]

5 minutes ago, SuperRu said:

Are we proving Michael Lavorgna's point here?

Did he have one?

[mansr]

4 hours ago, gmgraves said:

I dunno, but keep in mind that a digital potentiometer, while eliminating problems with impedance mismatch, must convert analog to digital and then back again. And we argue for hundreds of posts about the merits of various commercial DACs and now some are advocating digital volume control chips which do a do a double conversion? 

That's not what a digital potentiometer is. A digital potentiometer is simply a digitally controlled variable resistor. Here's an example of one: http://www.analog.com/en/products/digital-to-analog-converters/digital-potentiometers/ad5142a.html

[mansr]

9 hours ago, Ralf11 said:

I'm not understanding how mechanical speed variation in reading bits off a CD would affect SQ.  Shouldn't the buffers handle this?

Of course they should, and they do. Every CD player has to have at least a small buffer for the CIRC decoding. The decoded bits are clocked out using a crystal oscillator. Feedback from the buffering system regulates the CLV servo that spins the disc. The portable CD players that used to be popular would buffer several seconds of audio, allowing them to recover even if shaken badly enough that tracking was lost.

[mansr]

Just now, gmgraves said:

Indeed? Never thought of that! Never mind my criticism. The only digital volume control of which I've ever heard uses an ADC and then a multi step volume control which works in the digital domain, and then requires the digital signal to be returned to the analog mode via a DAC. Not a great high-end audio solution in my estimation. However the one you describe should be fine.

There are also devices like this one: http://www.ti.com/product/pga2311

That's basically a variable resistor combined with an opamp to produce a variable-gain device with fixed input and output impedance.

[mansr]

8 hours ago, 4est said:

It has been said that one of the issues is that analog engineers are not always the best digital engineers and vice versa.

So get an expert in each and let them build a DAC together.

[mansr]

21 minutes ago, gmgraves said:

At Schiit it's Mike Moffat for the digital stuff and Jason Stoddard for the analog designs. Both are legendary in their fields. Maybe that's the reason their stuff consistently seems to outperform it's price points. 

I've only had limited interactions with them, but they seem to know their schiit.