They split this thread off from the ESS Sabre thread and put it in the Vendor's Bazaar area. It has become more of a generic Twisted Pear thread, so the name should probably be changed at some point.
I should add that this is with DAC in voltage o/p mode with a high speed discrete component op amp acting as balanced to unbalanced & filter
The -3dB point of the op amp is around 200khz so the filtering and ringing that is visible is essentially from the buffalo.
🙂
The -3dB point of the op amp is around 200khz so the filtering and ringing that is visible is essentially from the buffalo.
🙂
This is the best I could get for a 10khz square wave
As far as I can see this is 3 peaks followed by a peak with a trough
perhaps 11.025khz would have been more regular - not sure - on my cd I only have decades
I'm amazed that such a crazy handling of a square waves of certain frequencies could come from a DAC that sounds so great. perhaps that's just how red book digital is.
If I rely on my eyes I would get worried but if I rely on my ears it's fine
I do wish though that I could turn off the oversampling on this great DAC to see how it sounds in that mode.
cheers
mike
As far as I can see this is 3 peaks followed by a peak with a trough
perhaps 11.025khz would have been more regular - not sure - on my cd I only have decades
I'm amazed that such a crazy handling of a square waves of certain frequencies could come from a DAC that sounds so great. perhaps that's just how red book digital is.
If I rely on my eyes I would get worried but if I rely on my ears it's fine
I do wish though that I could turn off the oversampling on this great DAC to see how it sounds in that mode.
cheers
mike
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Hi Mike,
Your shots almost look like the DAC is in Slow Roll off mode.
Those are very interesting scope shots, but I think the question was actually about the Buffalo32S which was measured and not the older Buffalo.
Cheers!
Russ
Your shots almost look like the DAC is in Slow Roll off mode.
Those are very interesting scope shots, but I think the question was actually about the Buffalo32S which was measured and not the older Buffalo.
Cheers!
Russ
Yeah - I was wondering about the roll off. I will switch it to fast roll off and have a look later on.
Bear just said the DAC so if he meant the new one then it's over to you Russ 🙂
Bear just said the DAC so if he meant the new one then it's over to you Russ 🙂
I thought "surely Mike's shots can't be right" so did some measuring myself ..... and blimey, mine look just the same in both fast and slow roll-off modes. Strange ..... 😕
Actually, putting aside the scope triggering problem, that's a very typical 10K square wave response. As you know, a square wave is devolved into the fundamental frequency, and a diminishing infinite number of successive odd order harmonics of the fundamental, with zero phase shift.
The first problem is that the first odd order harmonic is 30KHz, already way down the the sharp cutoff filter starting at 22KHz. The next is 50KHz, almost non existent in amplitude, probably 30 to 40dB down. Square wave analysis in an frequency bounded system, like RBCD (20KHz) is pretty meaningless above 1KHz or so. And that's a pretty nice looking 1KHz response!
Tom
The first problem is that the first odd order harmonic is 30KHz, already way down the the sharp cutoff filter starting at 22KHz. The next is 50KHz, almost non existent in amplitude, probably 30 to 40dB down. Square wave analysis in an frequency bounded system, like RBCD (20KHz) is pretty meaningless above 1KHz or so. And that's a pretty nice looking 1KHz response!
Tom
What is the general consensus on the "sound" of the DAC with fast & slow roll off.
I'm wondering about subjective conclusions
thx
mike
I'm wondering about subjective conclusions
thx
mike
mikelm said:
I stick to fast roll-off. Slow roll-off just does not sound right to me. It also looks much worse on the FFT.
Cheers!
Russ
Russ White said:
I guess the difference between what you would expect to see and my scope shots would be the different filters we have in our output stages.
I reigned mine in just enough to avoid upsetting my amp
do you see the differences in the 1Khz plot, the 10khz plot or in both ?
cheers
mike
Well, I was under the misguided apprehension that a slow roll off digital filter was desirable because it would give rise to less ringing . . .
Having just switched to fast roll off ( for the first time ) and checked the waveforms I cannot see any difference in the ringing at all.
Mmm - me no understand.
If slow roll off does not give less ringing why would anyone want to use it ?
I think subjectively it does sound a bit cleaner with fast roll off but not sure yet.
mike
Having just switched to fast roll off ( for the first time ) and checked the waveforms I cannot see any difference in the ringing at all.
Mmm - me no understand.
If slow roll off does not give less ringing why would anyone want to use it ?
I think subjectively it does sound a bit cleaner with fast roll off but not sure yet.
mike
mikelm said:
That's not ringing you're seeing, that's the Gibbs phenomenon. There's no way to get rid of it. It's expected.
Try looking at the impulse response in the time domain to see pre-ringing. The slow roll-off filter will reduce this. But it will also reduce the extreme high-frequency response. Some people want this intentionally because they believe anything in the 20kHz-22kHz "transition band" is likely to not contain useful information anyway.
I can't help thinking that digital audio would sound a lot better if the Gibbs effect and pre-ringing were eliminated.
In the world of analogue I've spent the last 10 years learning how to remove spurious stuff like that.
Seems odd to me that someone planned to have that stuff included in digital signals.
In the world of analogue I've spent the last 10 years learning how to remove spurious stuff like that.
Seems odd to me that someone planned to have that stuff included in digital signals.
mikelm said:
The Gibbs effect can't be eliminated because digital audio is a sampled system. The only way to get rid of it is by making the system continuous. That would be analog. 😀
rossl said:
That would be analog with infinite bandwidth.
There's no way of getting rid of it in any practical audio system, but there's no reason to either. There are no discontinuous sound waves in real life, because air pressure is never discontinuous, and anyway, our ears are bandlimited.
You are correct and it cetrtainly isn't worth worrying about. There are no square waves in music.
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