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
