After the transformer and line amp? What if the modulators have tricks to hide noise in the absence of a signal?
Note: forgot to mention earlier all dsd conversions were to DSD256.
Note: forgot to mention earlier all dsd conversions were to DSD256.
What problem did you have with the poly sinc gauss xx filters..
(poly sinc gauss long for safety, poly sinc gauss xla for the brave)
and ADSM7EC-v3
(poly sinc gauss long for safety, poly sinc gauss xla for the brave)
and ADSM7EC-v3
Preferably straight after the transformer.
Good point. When you play a soft low-frequency sine wave, you should see the noise ride on top of the sine wave when you look with an oscilloscope. If you manage to get it to trigger, or maybe with a one shot measurement, you can estimate the quasi peak-peak noise.
I'm curious if there is any relation with your ranking.
in that sense, I do agree with poly sinc lp - also I used that a long time. I've been asking because in my experience it's a calm and 'natural' filter, so I would chose that with less well tuned systems..
I found that gauss filters can excite the the treble.. they can sound very analytic. For me a well tuned system is where even with those the response stays natural and smooth but with that enhanced spatial reconstruction and resolution that the gauss variants are capable of
Playing a low level sine wav what I find is that with 3' long cable from dac output to transformer input, at the transformer input it looks just about like the unfiltered output of the dac (which is to say pulses at RF). Coming out of the transformer, scope vertical amplifier noise floor and ambient EMI/RFI dominate what can be seen. Only thing I have seen so far coming out of the transformer is some line level audio when I play music.
Mark,
Can you make FFT spectra with your scope up to Fs, IMO the above answer does not give any insight into the question.
Hans
Can you make FFT spectra with your scope up to Fs, IMO the above answer does not give any insight into the question.
Hans
Tried that after the transformer. No spurs, just a flat noise. Some of it just scope amp noise above 1GHz. Tried shorting the probe, removing the probe from the scope, etc. Environmental and scope amplifer noise dominate.
Spectra should be taken at the transformers input, not at its output, or alternatively at the 8n2 Firdac cap.
Hans
Hans
Marcel asked for after the transformer.
EDIT: I think the reason for wanting to take a look is to see whether differences reported subjective/discrimination of modulator and or upsampling filter sound could be attributed to, and or correlated with differences in noise visible on a scope. In retrospect, maybe not very likely. The differences found in reproduction of space/sound-stage were pretty subtle in comparison to the 8-bit resolution of a digital scope.
EDIT: I think the reason for wanting to take a look is to see whether differences reported subjective/discrimination of modulator and or upsampling filter sound could be attributed to, and or correlated with differences in noise visible on a scope. In retrospect, maybe not very likely. The differences found in reproduction of space/sound-stage were pretty subtle in comparison to the 8-bit resolution of a digital scope.
Last edited:
Just tried them myself. The 'long' version sounded a little thin on male vocals in the midrange, and a little off putting in some way (maybe slightly mechanical/unnatural) . OTOH 'xla' is kind of interesting. More musical and unusual clarity of reverberations, would be my initial impression. Would like to have some other people listen to it as well before saying more.
Last edited:
Any half-decent soundcard is able to measure the out-of-band noise up to fs or even up to 96kHz.
I would expect quantization noise to dominate from a hundred kilohertz or so to a few megahertz, but if I understand you correctly, you see no difference between DAC connected or probe shorted even there. Thanks for trying!
What I see coming out of the dac is a blur of RF pulses. Its a time domain view. Maybe I could go back and try an FFT with the scope before the transformer?