On Thu, 13 Jan 2005 19:57:41 -0500, Jon B wrote
> Recommendations so far:
>
> 1. Echo Indigo I/O
>
> Looks good. Only thing I'm worried about is the converters being
> inside the computer. Is it really well-shielded and flat noise
> floor? I guess if there's some whine but it's *much* lower than a typical
> sound card, I could live with that. They look pretty inexpensive,
> regardless. $180 or so. Maybe I should just get one and try it.
The converters in the Indigo sit just outside the computer. The card plugs in
and the converters/amplifiers/jacks stick out about an inch from the CardBus
slot.
Here's a picture:
http://www.stereophile.com/images/archivesart/1104indigo.1.jpg
The sound quality I have found to be very quiet, even at high gain- definitely
a cut above any internal PCI sound cards I have heard.
Here's an article that talks about Indigo's sound quality:
http://www.extremetech.com/article2/0,1558,1325716,00.asp
> > They deliver real-time performance at 96kHz, 24 bit
> > down to 32 samples.
>
> By "down to 32 samples" are you talking buffer size? Is this what
> JACK calls "frames/period"?
Yup. Your latency is "frames per period" / sampling rate.
> So PCMCIA is definitely capable of low latency, comparable to an
> internal sound card? (Comparable to PCI, I guess?)
It seems to be less an issue of the bus (PCI vs PCMCIA) and more an issue of
how the hardware is configured-- IRQ assignments, DMA on disks, kernel
tweaking, etc. For me, portable low latency was the deciding factor for going
with the Indigo IO and it has paid off.
> I am looking for something in between these in price range. $300 or
> so. The Indigo would probably be ok, but maybe better than that...
> Is there anything with MIDI, too? I haven't learned enough about
> MIDI interfaces to understand the kind of latency involved, or used
> it very much with ALSA, but something that could handle both at low latencies
> would be great. (Or two separate things, but I only have one PCMCIA
> slot.) I have a Midisport 1x1, but it has bad latency in windows,
> and I haven't bothered to figure out how to get it working in Linux.
Your latencies in MIDI are going to come mostly from the transmission protocol
itself. It uses a slow data rate, so it'll always have millisecond latency.
Good Luck,
-JP Mercury
Received on Sat Jan 15 00:15:04 2005
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