Hi,
On Thu, 26 Aug 2010 15:02:04 +0200 Clemens Ladisch clemens@ladisch.de wrote:
David Santamauro wrote:
Since upgrading my audio PC to 64-bit,
Hardware or software upgrade?
Both ... I should say the 32-bit linux test was done on different hardware. The events were:
a) pc1, fedora 11 32-bit both maudio delta 1010 and 2496 coexist happily b) pc2 new build to be a 64-bit machine c) pulled delta 1010 out of pc1, inserted into pc2 -- noise d) installed win7 64-bit in dual boot configuration on pc2, no noise with delta 1010
the delta 1010 analog inputs emit a constant 'hiss' -36 -30dB. Analog outputs and digital ins and outs are fine. The delta 1010 from a hardware perspective is fine as I tested it on the same pc hardware under windows7 64-bit.
In theory, this sounds like a driver bug.
So far, I have tested it in a 32-bit fedora, 32-bit windows vista and 64-bit windows7 all successfully. This problem arises only in 64-bit fedora.
Does the 32-bit Linux use the same driver version?
To be honest, I'm not sure exactly how to check. They are the latest versions of fedora 11 (32-bit) and fedora 12 (64-bit). srcversion from a modinfo yields different results.
32-bit fedora 11 Linux beethoven 2.6.29.6-1.rt23.4.fc11.ccrma.i586.rt srcversion: F7E1C076BE18C5DFF723A6E
64-bit fedora 12 Linux debussy 2.6.31.12-1.rt21.1.fc12.ccrma.x86_64.rt srcversion: 0B183929429B4C5102B7D09
If yes, then it's possible that the 32-bit and 64-bit kernels configure the PC differently; for example, there might be noise on the power line due to a different kind of power management.
another interesting angle... I thought it might be power or some kind of internal noise. How could I pursue that further?
David