DAC designs

[iansr]

I do intend to bring the Cambridge to Owston and perhaps also a (very rare) 3 box DPA DAC I've acquired that has variable dither settings.

[Andrew]

Ah, ok, so without filtering you get a image between Fs/2 and Fs of the difference signal. But given that Fs/2 is > 20k, then assuming this signal has no unwanted effect on the folowing amplifier its benign.

I can see though if slew rate limiting or IM was generated thne it could cause a problem.

Hmm, what stops imagining effects occurring at all harmonics of the various frequencies present in the signal, even below Fs/2?

I'm missing something here?

[Nick]

Hmm, what stops imagining effects occurring at all harmonics of the various frequencies present in the signal, even below Fs/2?

Possibly only my understanding.

I was wirking on the basis, that imagin in Ed's doc was described as creating a signal at Fs-f where Fs is the sampling frequency and f is the signal being reproduced. But assuming the anti-alising filter was in place when the A/D was done, there shouldn't be any frequencies above Fs/2 so the lowest frequency I could see from the above is Fs/2

I guess IM could be a killer here, if the dac outout Fs-f and f, then IM would give us a Fs - 2f.

As I said, I think it might very well depend on the bandwith of the amp you are using after the dac, and given the 211 is -3dB at 37khZ, that might give better results than (for example) Ian's F4s with -3dB at 400kHz odd.

[SimonC]

Was there any outcome from Owston about the different DAC's that were taken?

Simon C

[Dave the bass]

Was there any outcome from Owston about the different DAC's that were taken?

Simon C

Yes.

All of them made me not want to listen to Annie Lennox ever again

DTB

[Tony Moore]

Too right!

[Dave the bass]

I remember Marco's 'old skool' Sony got a few folk excited, Al's valve buffered DAC sounded good to me but maybe that was Phsycological because it had cute valve poking out the top.

Colins CD player direct sounded good even without a DAC.

Iansr's whizz bang beasty was popular think too but for me it was late and I'd had enough of the Lennox by then.

DTB

[al newall]

I think it was the edgy vocals that proved too much for many peoples tired hearing.
Consequently i reckon, the DACs were judged largely on which sounded the least offensive.

Different music/system may have produced more conclusive results, but time was running out.

Marcos DAC was probably the easiest on the ear, and didn't appear to have any obvious weakness.

Interesting to hear such easily audible differences between the DACs.
Something i hadn't really considered, till recently.

[simon]

The Annie Lennox track was specifically chosen to see how well the DACs coped with the nasty treble. I think it would have been interesting to have tried a completely different track to see if the perspective was the same. Unfortunately by that point we were getting a little "jaded" and in need of refreshment. Still, there's always another time, just not with the Lennox track!

[SimonC]

I think that choosing between DAC designs will need to be based on a longer audition period, especially as what sounds good initially can become tiring once you have to live with it for a few days. Nick commented on the difference between the Beresford and Ian's Cambridge became more audible the longer you listened.

If anyone has a multi 1543 and/or a 1541 they could loan out for a couple of weeks I would love to hook them up to my system to have a proper listen.

Simon C