The AD/DA convertors produce a noise floor of about -85dB when connected to cables that are not connected on the other end. Not great, but workable. When I plug them into my preamp, or any other device, however, the noise shoots up to -45dB making the convertors essentially useless. I have tried shielding the Pulsar card from the rest of the computer, but have been unsuccesful at lowering the noise floor appreciably, and am uncertain why. Has anyone managed to achieve better results, and if so how? I am wondering if the convertors might be picking up electro-magnetic interference from the onboard Sharc DSPs, or if my convertors are just shot. Also, do any of you know of a solution for pulling the entire card out of the computer by some type of PCI extension cable? It is my understanding that these do not exist, but it seems like one could be rigged up. If there isn't a workable solution, I'd appreciate any recomendations for a good quality external convertor that is somewhat affordable.
<font size=-1>[ This Message was edited by: gas2d on 2001-05-20 14:59 ]</font>
Help! AD/DA Convertors too Noisy
Re: Pulling the card out and into a PCI Expansion system: Yes, this is possible, however, I DO NOT suggest you do it. <a href=http://www.magma.com/>Magma</a> makes such devices, but they will essentially kill your PCI bandwidth between the card and CPU/main memory.
You don't mention which mic preamp you're using, but be sure that it's outputting a line-level signal. You get what you pay for in a mic preamp, and anything less than $100 is umm.. well...
I have used the Pulsar's AD/DA before and they are fine. Not spectacular, but much, much better than a Soundblaster Live or something.
As far as AD/DA converters, some people like the Fostex unit (RCA, non-rackmount) which is also the cheapest (about $250 new). I like the Alesis AI3 which is 1/4" and rackmount, for the price, about $350 new. If you really want the goods, then take a look at the RME converter box which supposively rivals even the Apogee converters...
Also consider some of the cheap digital mixers around on blowout ($499 ish!) that have faders and decent AD converters with ADAT output. They will even have some more effects, to boot...!
Better digital mixers can also be used as AD boxes with faders, too, check out the Yamaha 01v+ADAT, 03D+Adat, Spirit 328... Mackie D8B
You don't mention which mic preamp you're using, but be sure that it's outputting a line-level signal. You get what you pay for in a mic preamp, and anything less than $100 is umm.. well...
I have used the Pulsar's AD/DA before and they are fine. Not spectacular, but much, much better than a Soundblaster Live or something.
As far as AD/DA converters, some people like the Fostex unit (RCA, non-rackmount) which is also the cheapest (about $250 new). I like the Alesis AI3 which is 1/4" and rackmount, for the price, about $350 new. If you really want the goods, then take a look at the RME converter box which supposively rivals even the Apogee converters...
Also consider some of the cheap digital mixers around on blowout ($499 ish!) that have faders and decent AD converters with ADAT output. They will even have some more effects, to boot...!
Better digital mixers can also be used as AD boxes with faders, too, check out the Yamaha 01v+ADAT, 03D+Adat, Spirit 328... Mackie D8B
I'm using a dbx 586, and yes it outputs line level, however, every device I hook to the inputs produces the same result; an increase in noise of about 40dB. There's a sp/dif option for my preamp, but it's only 20bit and I'd much prefer 24bit. I was using a Tascam TM D-1000, and going digital at that point, but I hated the preamps and convertors. Going analog out of the Tascam RCA outputs also produced the same result. Could you elaborate on the problems with PCI bandwidth when inserting a cable between the card and the bus?
What kind of cables are you using? Try again with some high quality cables like Monster or something; my friend was having problems with a hum and noise too, but it was the cables. My noise floor is very low on the AD/DAs, but I don't really use them anyway, I use the ADAT and SPDIF and MIDI though.
Why not try the SPDIF, see if that helps? Also try lowering the gain (if possible) on the preamp. Remember to use a SPDIF cable (it's not just an RCA cable..)
Why not try the SPDIF, see if that helps? Also try lowering the gain (if possible) on the preamp. Remember to use a SPDIF cable (it's not just an RCA cable..)
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MeloManiac
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I don't have the digital out option on my dbx 586 preamp, so I can't use the sp/dif. When I had my tascam TM D-1K it worked fine. As far as cabling goes, I'm using Monster Cables 500 series interlink RCAs so other than being unbalanced, that's not my problem. And by the way, sp/dif cable, regardless of what you've been told, is merely well shielded RCA cable with a bit of "pro" tax added to the price. The poorly shielded RCAs that I was using gave me zero noise and no significant increase in digital errors over so called digital sp/dif cables.