On Sat, Jul 26, 2014 at 10:51:24AM -0700, Sam Mulvey wrote: Ah yes, I forgot to mention a bunch of stuff. - I'm already using the force-USB-1.1 hack in cmdline.txt - I've followed the guidelines at http://wiki.linuxaudio.org/wiki/raspberrypi - I'm using the autostatic repo for jackd and such. - The base distro is the most recent (January 2014, IIRC) Raspbian Wheezy distro Maybe this chip just sucks, but I'm certain that I've gotten good sound out of this exactly USB adapter before on x86 systems. -ken

On Sat, Jul 26, 2014 at 08:44:30PM +0200, Jeremy Jongepier wrote: I'll have to look again, but I'm pretty sure that it was the autostatic packge. No X, all unnecessary services disabled as suggested in your excellent guide, and a power adapter that can do 2A. Haven't tried amsynth, but mplayer has no problem, though only using raw ALSA, not JACK. I suppose I could try mplayer through jack. I ran the corruption test, it passed. I'm not sure what this means. I dunno, I kind of gave up on the project. Maybe I'll try again with a BeagleBone Black if I really wanted it to work. A friend gave me the run-down on why Raspberries are crappy, and couldn't argue. I've done quite a bit of work with BeagleBone's in the past (pre-Black days) and found them much better engineered-- real development boards. The dream 7 years ago was to have a portable, battery-powered, rock-solid, headless Linux synth that could be controlled with a keytar-configured USB controller for street busking and casual gigs. I'm not gigging anymore and can't imagine wanting to, so it's kind of moot now. And yet, having that project still un-completed-- but so close to being possible-- continues to nag at me. -ken

On 30/07/14 19:01, Gerhard Zintel wrote: The Udoo are a lot more powerful, 4 cores plus a SAM chip (Arduino Due) with proper ethernet, USB, audio, wireless, SATA plug etc. Depends what you need, but if you need things like lots of GPIO, including analogue, or reasonable networking and the built in audio is OK for you then their price (3 times a Pi) isn't so bad. Also, I keep running into the lack of documentation on the Pi, it looked good at first but ..., while the GPU interface on the Udoo has a lot more docs. Simon

On Friday 01 August 2014, Chris Bannister wrote: Sorry to disappoint you. This link was mainly to show that power consumption of Banana-Pi is lower than for Raspberry Pi model B (because Ken wrote: "The dream 7 years ago was to have a portable, battery-powered, rock-solid, headless Linux synth "). I thought the figures (I read it as specifications?) are in the other link I gave (http://hardware-libre.fr/2014/06/raspberry-vs-banana-hardware-duel/). For better specs see here: http://www.bananapi.org/p/product.html Gerhard

On Fri, 01 Aug 2014 07:42:06 +0200 Jeremy Jongepier <jeremy(a)autostatic.com> wrote: Exactly! This is something people seem to forget when they complain that it can't do this, or that. They also forget that the founders sank their own personal money into this project at the start, called on favours and twisted arms. -- Will J Godfrey http://www.musically.me.uk Say you have a poem and I have a tune. Exchange them and we can both have a poem, a tune, and a song.

On Sat, Aug 2, 2014 at 9:55 AM, Ken Restivo <ken(a)restivo.org> wrote: Not sure about USB performance, but you get a sub $100 board with a 1.7GHz quad-core processor and 2GB RAM already. See here: http://hardkernel.com/main/products/prdt_info.php?g_code=G138745696275 Their Pi compatible board is also interesting. For about $60 you can get something smaller than the original Pi with a screen, battery regulator/charger, extra USB ports, and additional ADC. http://hardkernel.com/main/products/prdt_info.php?g_code=G140610189490 http://hardkernel.com/main/products/prdt_info.php?g_code=G140609436593

On 30/07/14 17:50, Ken Restivo wrote: the 5V rail in the RPi A and B rev 2 (but it has improved quite a bit in the new B+ models, and was quite different in the original rev 1) seems directly connected to the USB outs, the 5V pins and the 5V holes while the miniUSB power inlet has a 6V 1.1A polyswitch limiting power in (which may be the reason you can get reboots when hotplugging USB devices). So if you connect power to a hub that sends that power back through its USB inlet you can power the Pi that way, plus whatever else is on the hub, without the 1.1A limit going via the Pi. A proper hub shouldn't be connected that way (I'd guess it should have a diode or some way of switching its source) and you should be able to power each separately. Hubs in theory shouldn't do it, but many do. You are bypassing the over-current protection on the Pi also, so better do it correctly, I'd guess the hub has some protection and the Pi alone won't draw too much, but you could certainly draw too much from the 5V pins on the header. USB leads to the miniUSB will often have considerable voltage loss if you try to put 1 amp or so through them, that is well over the spec for USB, so better make sure it is actually a power lead not just a USB lead, maybe full sized USB leads tend to be not so lightweight (so again better luck back through the USB outs)? Re 2A claims on power supplies ... when trying to set up a system that needed a good power supply the labels meant nothing, like labels on domestic audio amps I guess. I tested some by how long they took to charge my Samsung Tablet ... a new Apple power supply using the USB lead supplied by the Samsung took 16 hours, and almost anything plugged into the USB outs of the RPi caused trouble if I used it in the setup, it is labelled 5.2V 2.5A while the Samsung supplied one is labelled 5V 2A and takes about 1/3 that time to charge (with the same lead) ... this makes sense for an 8 amp hour battery, and it runs the RPi setup well. The new model B+ has a 2A polyswitch. It is said to need less power and now there is some kind of regulator circuit between the miniUSB and the 5V rail (there always has been one between the 5V and the 3.3V of course), so it is quite different. Very clean power would be vital for the analogue audio out, since it is just a very simple low pass filter on the board, filtering a bitstream. Simon