A good digital volume implementation is not simple and then it needs to have the post ADC gain optimized to ensure you are not running at too much attenuation on the digital side. Dithering the attenuated output is important.
In a system environment it can be a good solution but with individual components will run a high risk of getting the gain structure non optimal. The Berkeley Alpha dac is a good volume implementation but really needs a separate preamp on the output to get the gains aligned in many cases.
In a system environment it can be a good solution but with individual components will run a high risk of getting the gain structure non optimal. The Berkeley Alpha dac is a good volume implementation but really needs a separate preamp on the output to get the gains aligned in many cases.
Leaky Coupling Caps...
I have replaced many leaky pot and switch electrolytic coupling caps.
The symptoms are a scratching noise when the pot is moved, and a thump or scratching when switches are operated or rocked.
Dan.
Yes.
I have replaced many leaky pot and switch electrolytic coupling caps.
The symptoms are a scratching noise when the pot is moved, and a thump or scratching when switches are operated or rocked.
Dan.
Good move ... you won't be sorry, Christophe. My first CD player was the top Yamaha of the time, used an analogue volume out. Gave me hints of what was possible, but then started playing up, tracking problems. Dealer exchanged for the new model top unit, which used digital volume. This is when I started making real progress, and the breakthrough occurred ...As i use mainly Digital sources, my next solution for volume control will be exclusively in the digital domain. And i will add a ADC to deal with my analog sources.
JC will kill-me
Frank
Why? If totally in digital it works like charm, my still working 27 year old Yamaha beats the pants off nearly all digital plus analogue I've heard over the years. You just have to chuck the preamp ... sorry, John!
Frank
JC, thank you for these pearls of wisdom from the Jurassic days when you diidn't shy from getting your hands dirty with stinkin' measurements.
IIRC, you mentioned a wire wound pot which was your reference standard before Blowtorch.
Could you reprise your thoughts on these and explain how Blowtorch achieves its exemplary performance c/f supa dup wirewound?
You also hint at having done trials with some evil digitally volume controls eg PGAxxxx. Could you summarize your findings including any measurements you made? As these do not appear in any of your product, it won't matter if us Unwashed Masses misinterpret your measurements.
I font really have an idea. It could be phase shifts in the vocal range (but if you add a tweeter above 15k it shouldn't have any), or its not the speakers but the dac. Did u try with analog?
Btw I'm 35 and I can hear up to 19k.
I'm lucky enough, or kept well enough away from sound nasties so that I can still pick up 18kHz. It's borderline, have to focus a bit for it to register, but it's there. I make sure that when I sense the telltale signs that the ears have had enough, to back off ...
Perhaps one reason why I'm still so fussy ...
Frank
then dont say anything at all if you arent prepared to share a more 'optimal' solution
Esperado, qusp
Citation from oldier Wolfson white paper , claryfying my word "suboptimal"
Whole pdf is in attachment, I can not find it currently on webspace.
Citation from oldier Wolfson white paper , claryfying my word "suboptimal"
Always will be regulation in digital domain acompanied with relative increasing of quantizations errors and partially loosing of informations. You can manipulate 16 bit data with 32 bit resolution, but if you need e.g. 20dB attenution, lower valid data from original information get lost. That is why I prefer regulation in analogue domain, with fixed resistors ,at lowest acceptable impedance, and relay network. This solution offers best linearity and lowest own noise.
Whole pdf is in attachment, I can not find it currently on webspace.
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