Class D is just Dandy!

I was taking a look at the NAD C390DD integrated. I like the concept of being able to change out the boards as upgrades become available. Anyone have experience with the sound quality of that model?

Hi @autre

I got to hear the NAD Master series DAC two years ago. Cold, it was a painful screech.

I never heard it well warmed up, so I would strongly caution  you to get a good listen yourself.

I also heard Arcam, MUCH MUCH nicer. Like an inexpensive Ayre.

Best,

E

I don’t "blame" preamps for changes in frequency response. I say high output impedance causes frequency response changes which vary based on the load. This is an irrefutable fact based on simple serial circuit analysis. Anyone with a basic understanding of AC circuit analysis would conclude the same.

And I showed the math for why that is not so: the first half of your quote here is false, the second half being based on the first is thus also false.

                                             **Do the math**.

Its the coupling cap at the output, not the output impedance that governs the frequency response.

Example: I've seen ARC preamps with 20uf output coupling caps. If you put them on a 10K load, they will be as flat as they are on a 100K load in the audio passband. Yet the very same preamp according to ARC should not be asked to drive anything less than 30K.

Your claim to which I was objecting was that the higher output impedance of tube preamps leads to frequency response errors and the simple fact is this is not so- it depends more on the timing constant that may or may not be present at the output of the preamp in question.  I showed the math. If you wish to refute this, then show the math.

Yes I agree,Class D not Digital is Dandy.

I have reached 100 hrs on my dragon s500 and not really much change.It's a little lean and bright,nothing horrible,compared to my 600m's.I won't fully evaluate it till past 1000hrs,I have it playing in my 2nd system for now.Time will tell.

Kenny.