[PlanetCCRMA] Re: YAUAQ (yet another USB audio question): Roland UA-25

Luis Garrido garrido_luis@hotmail.com
Fri Jan 14 09:16:01 2005

Yes, the UA-25 works with Planet CCRMA.

I managed to make it work in advanced mode 44.1 KHz 24bit + MIDI, so I can 
trigger qsynth from my MIDI keyboard with a latency of 5.8 ms (with some 
xruns if the soundfont is complex, seems my PIII 500MHz is a bit too slow).  
I use FC2 and the edge kernel. I keep my Planet up to date as for 13/01/05. 
By the way, the edge kernel makes sometime funny things like it hangs very 
early (after the first appearance of 'audit') or it enters in a sort of a 
step-by-step mode, where you have to press a key to keep the booting process 

Some caveats:

- In qjackctl, if I use only 2 periods per buffer (the default value), I 
must raise the frames per period to 2048 to avoid crackling noise (this 
noise doesn't come from xruns, so I guess it has to do with how the USB 
protocol is implemented), and the latency is then too high. However, a PPB 
of 4 and a FPP of 64 give 5.8 ms latency and no noise.

- The battery of my laptop IBM TP600X died months ago so now I use it always 
plugged. It seems that if I remove the battery from the computer I cannot 
power the PC on, so I had to let the battery stay. However, the APM (or 
ACPI?) system will detect low batt charge and slow down the processor to 133 
MHz (i.e. hundreds of xruns). Therefore I had to use use the IBM utilities 
to disable this feature (no, with this computer you don't have a BIOS menu 
to do that, so you have to use either DOS or Win9x software). You can check 
your processor speed with the command :

cat /proc/cpuinfo

This is my first experience with Fedora and I would like to share a couple 
of thoughts:

Great hardware detection and easiness of installation and configuration. The 
multiboot flaw of FC2 is terrible. I think the warning at Planet's homepage 
should be clearer to spot, like adding a red frame or blinking it or a 
attaching a danger icon.

Cool if you have a recent PC (lots of MHz, MB, GB respectively) and little 
time to hunt for drivers and tweaks. I think is a good choice of Nando 
focusing in this distribution for the average computer music user: people 
time is more expensive than hardware, nowadays. Compared to other music 
distros, Planet keeps moving on at a great pace, you only have to look at 
the changelogs. People like me, who happened to buy brand new audio 
hardware, need the latest kernel and ALSA drivers (this made me move away of 
DeMuDi after spending three days trying to compile a suitable kernel).

However I miss the fine grain control that you have in Debian to decide what 
to install or not. For instance, now I would like to clean up some of all 
those 3 monster GB that got installed. I want to reduce the memory 
footprint, the CPU usage and the booting time of my system, e.g. by:

- Getting rid of Gnome and setting up a simpler fluxbox X system. I hope 
this will decrease both memory and CPU usage. Perhaps turning off font 
antialiasing as well.
- Hunting down for services I don't really use. They don't seem to use CPU 
once started, but they use RAM, disk and time to load.

I'll keep the list informed. Any feedback or suggestion is very welcome.