I made a list of current Multibit/R2R DACs, maybe someone will find it useful.
Great list! Only thing that comes to mind immediately that I don't see is Lampizator: http://www.lampizator.eu/Fikus/DACs.html
I made a list of current Multibit/R2R DACs, maybe someone will find it useful.
Not sure why I forgot Lampizator. The list was originally inspired by a NOS DAC list on Audiostream. I decided to look for further entries, and the list slowly grew, particularly the last year or two. As I haven't seen a similar current R2R upshot anywhere else, I thought it might find some use on HeadFi also, rather than just keeping it local (Hoved-fi). Anyway, I will of course add Lampizator.
Among the things that made the TDA1543 so revolutionary and so low-cost to implement were the many integrated features.
It has a built in S/PDIF receiver, a built in demultiplexer (L and R signal separation), built in digital filters and output stage, and a single +5V power supply. Comparing this to the TDA1541 which required two additional ICs for S/PDIF receiving and demultiplexing, external digital filters and op amps, as well as a five voltage power supply, companies now had a way of building a CDP in a fraction the size and at a fraction the cost.
I don't want to get into a debate with anyone, but I'm literally looking at two data sheets for the TDA1543 DAC chip distributed by Philips.
And I'm sorry to say, but implying that <5uV PSU noise is a necessity for 20-bit output at RMS level is nonsense.
If this was the case, a basic workaround would be to work with inverted signals which would cancel out the common mode psu noise and lead to an infinite improvement.
Can you please explain why you think its nonsense when using a single ended DAC?
This would account for the dozens of TDA1543 DAC designs that use no receiver chip, no external op amps, and no digital filters...not much more than an S/PDIF input, a +5V power supply, and a pair of coupling capacitors at the output.
Now that some of you are bringing up other factors, how about background noise and listening levels?
A quiet room has about 30dB of background noise. This means we can not hear any sound much below 30dB in volume.
And most of us listen at no more than 100dB.
Subtract the 30dB background noise and we are left with only 70dB of audible dynamic range.
So when Sony and Philips developed the 96dB dynamic range of the Red Book format they knew what they were doing.
And there are other recording engineers and electronics engineers who say frequencies above 22Khz are not audible, and that 44.1khz 16bit is all that is needed.Many renowned recording engineers have written white papers stating that it is not the 16-bits but rather the 44.1KHz that is the major limiting factor in the Red Book format.
Do most of you realize that the maximum dynamic range of a stereo LP record is less than 65dB?
Because it makes the assumption that PSU noise goes unattenuated into the signal. This is a false statement, based on the understanding that DAC signal is a time modulated function of the voltage input. This is not true. Thousands of commercial products have power supplies with multiple milivolts of noise, which should result in 60db SNR. You'll struggle to find measurements as bad.
I take your point regarding signal to noise, but we are talking about bit depth, and I have seen measurments of commercial 16 bit DACs which have shown them to only have a bit depth of 14-15 bits of resolution. The least 1-2 significant bits can get swamped with noise, and I have found this to be audible, particularly with the TDA1543 chip, which though pleasant to listen to, is not renowned for its "detail" levels.
[/QUOTE]This is perfectly correct, but the reason for this is the noisy integrated current source or internal logic of the chip. I think you'll admit that even supplying the TDA1543 with 0.1uV power supply will not get you the lost bits back.
It is perfectly true to say noise at the output will limit the audible bit-depth, but it is very false to say that power supply noise = line level noise.
Glina, my purpose in posting about the TDA1543 chip was not to get into a debate on the various versions of the TDA1543 chip, but rather to confirm the reason there are so many wonderful sounding low-cost DACs using the TDA1543 chip is that it requires fewer power power supplies and fewer external parts. The TDA1543 has built in L and R channel demultiplexing, a built in voltage output stage, a single voltage power supply, and it requires no external parts following its voltage output. Compared to most vintage 16-bit R-2R DAC chips the TDA1543 requires about 25% the overall circuitry to build a DAC.
Any argument there?