Yet Another DIY DAC (work in progress)

[Tam Lin]

I've been called many different names, some not so complimentary. I think Tam is appropriate for this venue.

[Filterlab]

Tam it is then.

[shane]

Marco, have you never heard Sandy Denny? You really should sometime. Without doubt the greatest female voice to come out of the UK last century. (You'll have heard her on Led Zep IV, but that doesn't count...).

[Marco]

I'll check her out then Shane - got any good links?

Marco.

[snapper]

Hi Tam Lin,

I meant to ask, are you from the US/Canada region rather than the Carterhaugh in Scotland? Where exactly is the Carterhaugh where you live? I think we got it wrong!



Marco.

Tam Lin

I forbid you maidens all that wear gold in your hair

To travel to Carterhaugh, for young Tam Lin is there

Marco, have you never heard Sandy Denny? You really should sometime. Without doubt the greatest female voice to come out of the UK last century. (You'll have heard her on Led Zep IV, but that doesn't count...).

I'll check her out then Shane - got any good links?

Marco.

I'll bring some down.

[shane]

I'll check her out then Shane - got any good links?

Marco.

There are a couple of websites dedicated to her, but they don't get across the sheer emotional power of her voice. My favourite tracks are "Who Knows Where The Time Goes?" from the Fairport Convention album Unhalfbricking, "One More Time" from Rising For The Moon, and "Banks of the Nile" from the eponymous album Fotheringay. Sounds like Snapper is in a better position to complete your education, though!

Not forgetting The Battle of Evermore on Led Zep IV, the only time a guest vocalist ever appeared on a Zep album.

[Marco]

Great stuff, guys, - cheers!

I like Fairport Convention so I'm sure SD will hit the spot

Yep, I'm sure Snaps will duly educate me on all matters Sandy Denny over the next few days

I do like folk music.

Marco.

[Cotlake]

I do like folk music.Marco.

Hmmm, bring some along to the next Owston to be sure not to ruffle any feathers, PP or SE regardless. You know it's always safe to play safe

[Telstar]

Today some would argue that the minimum requirements set by the CCRMA study are too severe and that today’s DVD-A and DSD are sufficient. I’m not so sure. There is always room for improvement and until we can do 32-bits at 1MHz, we will never know.

DSD is so flawed in its implementation that i wouldnt consider it at all. Audiophiles likes it because it rolls off HFs, and sounds smooth, thats it.
DVD-As, which are 24/96 pcm come much closer to the ideal. Unfortunately the lack of good transports (the only one that i could define such is the esoteric ux-01) and quality DACs compromised its diffusion and now its a dead standard.

Computers come to the rescue. Digital, master-quality, uncompressed tracks are (finally) a reality now, and from direct and undirect experience i can say that already 24/88.2 comes out close to the ideal.

In one study made by Chord they conclude that around 700khz sampling rate is required for lifelike reproduction. Above that the human ear perceive only tiny feelings, but those go up to 1,5Mhz. I tend to believe them. The point is how to reach that sampling rate without digital filters that do more bad than good.

Another important point, often ignored, is that the upsampling, if we want to do it, has to be done by an integer, i.e. the redbook standard should be upsampled at 88.2, 176.4, 352.8, 705.6. and i would stop there. 16x direct interpolation is too costly to obtain. But if already 176.4 khz sound so damn good (listen to reference recording hrx files), 8x would be my ultimate goal.

I dunno about bitrate. I think that real 24 bit can be enough, but thats not reality yet (dont confuse with wordlenght, real 24bit means 144dB sn/r).
I'm not sure what 32 bit gives us more with the dacs currently available. There is no R2R 32 bit dac that we could use, altough in military applications those exist.

OK, i think i have said enough for my first post, and i have yet to finish reading this thread.

[Tam Lin]

The point is how to reach that sampling rate without digital filters that do more bad than good.

Easy. Just record at the same sample rate you want to use for playback. What do digital filters have to do with it?