This is not entirely true.
Ideal pot does it, but an actual pot shows a not constant input and output impedance.
A ladder one shows a good approximation of a constant input impedance, but a not constant output impedance - not a real problem.
Of course you can design your own ladder that shows a constant output impedance, but then the input impedance is not constant.
There are circumstances in wich you want a constant output impedance, but this is not that one.
Here we want a fixed input impedance and the only (cheap?) passive way is to use a stepped ladder pot.
Simple question here:
Am i able to make dsp changes via software onto a genuine pcm audio file and then via software to upscaling to dsd on the fly?
Or i will loose the dsp ability?
Am i able to make dsp changes via software onto a genuine pcm audio file and then via software to upscaling to dsd on the fly?
Or i will loose the dsp ability?
PCB Group Buy Update
PCB Group Buy Update: Since ordering the PCBs I've had some PMs asking to buy boards and I have so far managed to squeeze people in, however, as of this moment the PCBs are 'Sold Out'.
I am keeping a small number of boards back just in case anyone's boards get lost in the post; I will only offer them once those who have paid for boards have received them.
Ray
PCB Group Buy Update: Since ordering the PCBs I've had some PMs asking to buy boards and I have so far managed to squeeze people in, however, as of this moment the PCBs are 'Sold Out'.
I am keeping a small number of boards back just in case anyone's boards get lost in the post; I will only offer them once those who have paid for boards have received them.
Ray
PCB Group Buy Update
PCB Group Buy Update: The boards have been fabricated and are now on their way to me.
Ray
PCB Group Buy Update: The boards have been fabricated and are now on their way to me.
Ray
Hi.
I use lf =470 R, Cf = 0.015 uf.
Or 3.3k and 1000pf
I still see white noise.
Thanks
470R/0.015uF will give you a -3dB point at around 22.5KHz whereas with 3K3/1000pF -3dB will be approx. 48KHz?
When you say you can "see white noise" do you mean see on an oscilloscope or do you mean you can hear the white noise?
I've been using a 1K0/3.9nF filter (approx. 40KHz -3dB point) and have heard no white noise on the outputs.
My amps have a bandwidth out to 100KHz and I hear no noise with a simple first order RC filter?
Then it is oke for you.
Here with RC filter also noise, not much but on the headphone it is not nice.
Here with RC filter also noise, not much but on the headphone it is not nice.
Ok.
But if you hear white noise with an high frequency LPF, better you change DSD upscaling - 1X---->2X----->4X.
With 1X DSD - and maybe 2X - you can hear the noise because is very close to the audio frequency.
If you increase the upscaling, alias (noise) goes far away and then a simple RC filter is ok.
But a wide frequency amplifier always wants a steep filter, not against the noise, but because it can destroy your tweeters - if your tweeters are wide frequency too.
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iperv has a good point about the DSD rate, what are you using?
I only use DSD256 and would go higher if I could.
Also, I've just seen a post from Gentlevoice over on Acko's Direct DSD thread that suggests JRiver and Foobar are noisier than HQPlayer - I think you said you use JRiver? Perhaps it would be worth trialling HQPlayer if your hardware is up to it.
Ray
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See reply below,
Reply 263.
http://www.diyaudio.com/forums/digital-line-level/273474-best-dac-no-dac-27.html
Attachments
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Please try donlaod this file and test it:
this track: Ave Maria. Andante.flac
https://www.fshare.vn/file/3D8UAKOI9HE8
I will do, but not at the moment as last evening I dismantled some of my project as I need the USB board for an experiment.