Yup, it is a bit surprising not least since I was very careful with the layout to make sure it was symmetrical (although I'm not sure small differences matter at these frequencies). Do you think component tolerances could cause this? I also use the RR1220 0.5% Susumu's for trials ...
Thanks also once more for your outlining of what happens with a FIRDAC relative to the number of taps. If I calculate it correctly then for DSD64, 8 taps, and a tap T distance of one sample period then the - 3.92 dB frequency would be 352.8 kHz (1/(2*8*354 ns) ... That does not sound very troublesome (?), but for more taps could be, I suppose ... And for higher sample rates this frequency will go up. Hmmm ... interesting - thanks, Marcel!
Cheers,
Jesper
I finally know where the concept of the bandgap came from, and all it took was a look at Wikipedia. It's not Electronics Letters, but D. F. Hilbiber, "A new semiconductor voltage standard", ISSCC Digest of Technical Papers, 1964.
According to Wikipedia, it was the very first paper about bandgap references. In the early 1970's, variants that require much less voltage and produce much more noise were invented, which are used all over the place now.
According to Wikipedia, it was the very first paper about bandgap references. In the early 1970's, variants that require much less voltage and produce much more noise were invented, which are used all over the place now.
PRR has posted the article here: https://www.diyaudio.com/community/...ith-ic-voltage-regulators.359652/post-7021353
Just in case anyone wonders why there is so little progress in this thread lately: I first had to recover from COVID-19 before I could send the DAC PCBs to Ray, and then I caused a major delay by filling in customs forms incorrectly. The PCBs are now stuck in an English depot somewhere.
Hi Marcel, Hope you are fully recovered from COVID. It can linger in some folks for a long time.
Marcel, I made enquiries and the boards will be sent back to you shortly, then maybe we can try again?
Of course, but according to the track and trace code, at the moment they are still in the same old depot.
The one I built is in England, waiting until Ray has time to further validate it. There are a couple of personal and geopolitical reasons why Ray can't spend much time on the hobby.
This is extremely interesting! I'm still learning about the workings of ValveDAC (amazing work). Love this project.
Yes, it is with me to try but regretably my personal situation has prevented me from doing much in DIY audio land. I am starting to re-engage but my immediate priority is to complete a build of a Valve DAC for a friend, then I'll get to the RTZ DAC. Apologies to Marcel, et al, for my tardiness.
Now I've got the second Valve DAC working and have minimal work to button it up I'll have time to give Marcel's RTZ DAC a listen - I'll aim to fire it up this coming weekend.
I've started to hook up Marcel's RTZ prototype.
