Search found 230 matches

by abraxalito
Mon Jun 22, 2020 9:06 am
Forum: Computer Audio
Topic: Computer Audio Blasphemy, nige tries Another SD Card Player
Replies: 464
Views: 61573

Re: Computer Audio Blasphemy, nige tries Another SD Card Player

My screen has given up the ghost (except for the backlight) - but still it plays out audio, mostly.
by abraxalito
Tue Apr 28, 2020 4:20 am
Forum: Computer Audio
Topic: Computer Audio Blasphemy, nige tries Another SD Card Player
Replies: 464
Views: 61573

Re: Computer Audio Blasphemy, nige tries Another SD Card Player

tims wrote: Mon Apr 27, 2020 12:15 pm I can't find much in the way of say an I2S to S/PDIF converter
Something like this, which is used to create an S/PDIF output for a RPi would work I reckon : https://item.taobao.com/item.htm?spm=a2 ... t=4#detail
by abraxalito
Wed Jan 09, 2019 4:33 pm
Forum: Computer Audio
Topic: Computer Audio Blasphemy, nige tries Another SD Card Player
Replies: 464
Views: 61573

Re: Computer Audio Blasphemy, nige tries Another SD Card Player

This one's using an ATS2825 - it doesn't mangle the ends of tracks like the more expensive one so I'm preferring it. So far its been the height of stability, nothing fazes it, not even pulling out the card while playing, it mutes gracefully.
by abraxalito
Tue Jan 08, 2019 6:56 am
Forum: Computer Audio
Topic: Computer Audio Blasphemy, nige tries Another SD Card Player
Replies: 464
Views: 61573

Re: Computer Audio Blasphemy, nige tries Another SD Card Player

Here's another Taobao offering which is considerably cheaper : https://item.taobao.com/item.htm?spm=a230r.1.14.73.5c44219c1n029o&id=542592077587&ns=1&abbucket=6#detail . This has no screen but does have a downloadable APP (Android/iPhone) which gives access to the music on the SDcard and...
by abraxalito
Mon Dec 10, 2018 3:07 pm
Forum: Computer Audio
Topic: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD
Replies: 126
Views: 25173

Re: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

I can't see how having two Rs (one on each output) to GND changes anything. Though his output voltage might be measured differentially between the two, that wouldn't change the offset, which would be zero measured between the two output pins.
by abraxalito
Mon Dec 10, 2018 2:02 pm
Forum: Computer Audio
Topic: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD
Replies: 126
Views: 25173

Re: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

He's saying that the BPZ current is 10mA, presumably by virtue of over-volting the chip and decreasing the Iref resistor (10k->6k1).

But if your I/V resistors are 135R rather than 270R you'll get half his offset voltage i.e. 1.35V not 2.72V.
by abraxalito
Mon Dec 10, 2018 12:09 pm
Forum: Computer Audio
Topic: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD
Replies: 126
Views: 25173

Re: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

Dc offsets are circa +/- 2.75v on the differential outputs at 133ohm iv Think it's either 800 to 1000mv output ac I went over to the DS to confirm - its putting out 6.2mA at BPZ, the total swing is 7.8mA. So I'd expect 800mV DC on those 135Rs and the swing is between 300mV and 1.3V so 370mV RMS. It...
by abraxalito
Sat Dec 08, 2018 1:24 am
Forum: Computer Audio
Topic: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD
Replies: 126
Views: 25173

Re: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

Yes, that's the one. You can use J327Rs they're only slightly poorer (higher capacitance) than the J56 but you can run them hotter. I'd run the bias nice and toasty, say about 40mA to get an output impedance down below 1ohm, then use a series R (say 4.7R) to keep it stable with the parasitic capacit...
by abraxalito
Fri Dec 07, 2018 2:48 pm
Forum: Computer Audio
Topic: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD
Replies: 126
Views: 25173

Re: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

https://www.diyaudio.com/forums/diyaudio-com-wiki/250673-opcs-ntd1-project.html just thinking out aloud abrax what you think of this? I had a look at it a while back when I was designing I/V for my own DAC. While I like MOSFETs in I/V stages this one seems to waste a whole lot of power by running f...
by abraxalito
Fri Dec 07, 2018 1:47 pm
Forum: Computer Audio
Topic: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD
Replies: 126
Views: 25173

Re: NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

I've got 2 270s in atm If I remember right anything between 100 and 150r seemed to work just fine Here's a LP filter which gets rid of a whole load of ultrasonic stuff. It doesn't do NOS correction - do you need that? It can be tweaked to add some HF boost to counteract the first-order hold functio...