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  1. Black Sliver

    Stop the sirring noise!

    That's why I wrote "Assuming the IC runs stable and is correctly compensated [...]". You normally select components from a table of "reference designs" to rule out instable operation. "Skipped" output swings would potentially be another source of audible wave forms though...
  2. Black Sliver

    Stop the sirring noise!

    You are right. "On top" is the wrong wording (which is why I used quotes). Nevertheless. If you switch an AC signal, you get f1*f2. f1 being the ripple on the input (capacitor), f2 being the switching frequency. Or am I wrong there? But yeah.. it's possible that it is totally unrelated to that...
  3. Black Sliver

    Stop the sirring noise!

    Mixing f1 with f2 produces f1+f2 as well as f1-f2 afaik? You could wolfram alpha plot sin(2*t), sin(3*t), sin(2*t)*sin(3*t), t=0..3*pi to see the effect. I meant Interference in sense of multiple frequencies put "on top" of each other resulting an audible waveform. Not in the sense of EMI. (See...
  4. Black Sliver

    Stop the sirring noise!

    I would avoid drastically changing the layout/routing at this stage in a project... esp since you can't be certain that the noise will be gone in the final device (since it's probably an interference between two signals/frequencies). Just to be sure... have you tried hot glue or epoxy (UHU plus)?
  5. Black Sliver

    Stop the sirring noise!

    Not sure how accurate this still is, but one of our suppliers once told me there is no conflict-free tantalum... Like.. mines exist and you can buy it but there is no way to guarantee it. Anyway: http://www.kemet.com/conflictfree if that helps you sleep. :)
  6. Black Sliver

    Open... and close... and open...

    Is "connecting to usb" a USB device or a USB charger? Is it the same noise? Does it change if you do both? You are aware that the layer build-up changes the impedance? If you only keep half of the layers, the board would be half the thickness (and the result is still not 100% accurate), if you...
  7. Black Sliver

    It's all white!

    Ah... you're right. (But besides it's not really part of USB, most "regular" chargers I've seen are "short or 100Ohms between D+ and D-").
  8. Black Sliver

    Keep cool!

    That's not true at all. They manager their own security patches. See https://usn.ubuntu.com/usn/usn-3341-1/ for your example. Debian is often faster, but compare https://wiki.debian.org/LTS to https://www.ubuntu.com/info/release-end-of-life for security update lifetime (plus debian LTS is not as...
  9. Black Sliver

    Keep cool!

    Speaking from experience: because of the release schedule, supported packages and LTS. At home I prefer arch (rolling). Ubuntu lies somewhere between debian and arch. Having support from canonical would be nice for promotion, but they only promote "Ubuntu Core" for ARM/embedded at the moment...
  10. Black Sliver

    Keep cool!

    Sounds like up-/down-sampling issues to me. PA has to re-sample if mixing streams of different sample rate. It will either open the card with 44.1 or 48kHz and re-sample all non-matching streams. "Cheap" sound cards only support 48/96/192kHz and are crappy at up-sampling (modern formats like...
  11. Black Sliver

    Keep cool!

    I know. That's what we used to do before PA. But you'd need an ALSA driver for that -- two OSS devices are easier to explain.
  12. Black Sliver

    Keep cool!

    If you think about per-application transitions from handset to handset and maybe to blue tooth, PA is the easier choice. You'd need something like PA (= virtual "default" ALSA device) with HW mixing support and configuration interface for that. I believe having two "OSS" sinks that get mixed...
  13. Black Sliver

    Keep cool!

    Afaik that's the goal on "HW-level" (channel mapping + resampling) but has still driver issues. On the other hand, leaving channels as they are up to userspace would have the benefit of being less confusing... not sure what the exact plans are. The userspace mixing will always be done in...
  14. Black Sliver

    Keep cool!

    Besides not using available hardware power (for mixing), the only problem with pulse right now is the magic buffer™, that's not going away. Streaming a pulse stream over network or from one device to another (e.g. capture card in -> onboard out) will/may induce an increasing delay, I guess...
  15. Black Sliver

    It's all white!

    @netcat isn't that just the acquired memory POOL? (Since java does it's own memory management) @Lightkey I still stand on the point that a CPU core that can't be cooled is a bad power design and that (a lot of) recent SoCs do have cores that can be cooled; mine IS fairly recent (as in the age)...
  16. Black Sliver

    It's all white!

    Because its one of the few you can "hack" and touch. The power budget of a single ARM core stayed the same; it's a few companies that squeeze way to many cores into the chip, or overclock it (without a proper cooling solution), that screw their power design. No idea what you have, but my current...
  17. Black Sliver

    It's all white!

    Only distributor charges ~10€ excl. tax for MF10A03A (10mm x 10mm) and MF15B05 (15mm x 15mm) :/ Even when throttled? Is it at least (a lot) cheaper than the other one? :D
  18. Black Sliver

    It's all white!

    SIMD (neon) and GPU is far worse than CPU. The RPi and (most) atom boards, for example, can run at 100% CPU with the stock cooling as long as you don't use neon/sse/avx/... or the GPU. You'd have to move all signals (USB, etc.) over the flex between top and lower case, which is just crazy (and...
  19. Black Sliver

    It's all white!

    Sounds nice. Do you have a name/part number/price/source?
  20. Black Sliver

    It's all white!

    I've seen posts about failed ANKER cables (micro USB, arcing, smouldering), but I personally had no problems so far and still buy/recommend their stuff.
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