| miab wrote:|
|Yes the Bidat does lock 48khz very well and so does the Idat-m. Something even more suprising and coming from someone that knows these dacs very well is that on a few samples of Bidat they even lock at 96khz! Alas I am not so lucky. Mine is 44.1 and 48 only. I downsamle 88.2 to 44.1 and 96 to 48 for simplicity of computer processing and the elimination of any potential issue's. |
About bits. The datasheet for TDA1547 clearly states 108db of dynamic range for this chip which would be in line with a 18 bit dac. A 20 bit dac should in theory be capable of 120db. I'm not sure what to make of this. I have played the same tracks at both 16 bit and 20 bit and at this time I believe the 20 bit to have the slightest of advantages. I must admit that I might not be able to tell in blind testing at this point. 48khz vs 44.1khz is easy to tell though.
Miab, Bidat specification said that it is 16 to 20 bit input.
…but the last 4 bit of 20Bit signal will not be processed. I did research that subject in past myself and asked a few different people. I do not remember already who explained it to me, it might be John Write. You are in Canada, get in tosh with him and he can shade more light for you - ff Bidat has true 18Bit chip then it very much might toss out not 4 upper bits out 20 bit stream as I said above but 2 bits. BTW, I do not recognize 18bit – it does not make sense to me. If you are in CD-compatible world then you at 16 bit and this is your threshold. If you jump out of the CD would and right-read uncompressed PCM files then why would you limit yourself with 18 or 20 bit – you for sure would go for full 24 bit. Well, there is no such a thing as true 24 bit or cause but why not to use the max bit depth is available?
Also, as I said – I am very surprised that Bidat reads 48K. I was trying to feed Bidat with 88K and it does not like it. Bidat shall recognize the sampling rate in the incoming stream and PLL own clock to source. Usually the phase-locked loops in DACss are very narrow and this is why most of the DACs that do 44X and 48X has in fact two different clocks. Does Bidat has such a wide PLL window that is tune itself to 48K? That would be funny but since you report it I guess it is funny.
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche