Re: Some basic Audio device questions
Re: Some basic Audio device questions
- Subject: Re: Some basic Audio device questions
- From: Shaun Wexler <email@hidden>
- Date: Thu, 13 May 2004 21:03:44 -0700
On May 13, 2004, at 6:56 PM, Jeff Moore wrote:
Which devices are you talking about? Most of Edirol's devices are USB
and use our class driver in one fashion or another. The UA-3 I have
here seems to report the proper rates and does ok when I switch the
sample rates, even on the fly. I don't see any crashes or anything
like that.
I don't have an Edirol either. A couple of my users had problems with
them in early 2003, but I haven't heard of any problems since Panther.
I'm not familiar with any of Sound Devices' stuff.
http://www.usbpre.com
It's probably the most solidly constructed 2-ch USB interface
available; it's clean and has nice sounding pre's w/+48v. Most of us
"pro" live-sound guys use them for dual-ch FFT analysis, when we aren't
toting around the larger FW 8x8's on tour, etc.
AMS used to read the low range and ignore the high range value, which
was apparent in the USBPre driver which (correctly) reported an
output range of [5k, 55k]. To appear correct in AMS, it was changed
to report several ranges: [32k, 32k], [44.1k, 44.1k], [48k, 48k].
All of this is from memory; honestly I haven't mucked with it for
several months... since AMS became part of Panther, I eliminated my
pref's tab that previously performed those duties in 10.1/10.2.
AMS has been around since at least Jaguar and I think it was in Puma
and Cheetah, but I can't remember. It was rewritten in ObjC for
Panther.
At any rate, there shouldn't be anything wrong with reporting a range
of 5k-50K. I have a pair of USB speakers sitting here on my desk that
report the exact same range, and they seem to show up OK in AMS and
HALLab. A workaround shouldn't be necessary. I don't have a USBPre, so
I can't look at why it might be throwing things for a loop, but it
smells like a bug that should be filed in Radar, especially if this
device uses the class driver.
In 2002, Sound Devices hired a 3rd-party developer to write an OS X
port of their "PC-to-Mac OS 9" port of their original driver. I
offered him some help when he was trying to get it working, and he sent
me copies of their code, which he adapted from one of Apple's samples.
The device doesn't work with Apple's default USB driver, because it has
a 6-second hardware initialization during which it must be switched to
high-power (500 ma) mode by the driver.
--
Shaun Wexler
MacFOH
http://www.macfoh.com
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