Author Topic: usb or pcmia interface (Read 7081 times)

ropscot · « **on:** December 18, 2003, 06:21:30 PM »

I just recieved my gateway laptop in the mail, so now im looking for a recording device for it, I need something that I can record from the soundboard and my mics at the same time, can someone recomend a interface
thanks
Ron

jpschust · « **Reply #1 on:** December 18, 2003, 06:25:32 PM »

how about the ua-5? pretty good option and matrixing is totally possible with this unit. usb in :-)

ropscot · « **Reply #2 on:** December 18, 2003, 06:26:40 PM »

does it require ac power? also how is the sound quality
thanks
Ron

nic · « **Reply #3 on:** December 18, 2003, 06:39:47 PM »

pcmcia is the better interface. you can also get a firewire pcmcia card if the laptop doesnt have a firewire port...though most firewire interfaces are usually a bit bigger(ie, meant for racks), though, units such as M-Audios Firewire 410 is small and gives you the mic pres and inputs for matrixing...this unit can pull power from the firewire bus.

ropscot · « **Reply #4 on:** December 18, 2003, 06:42:38 PM »

yea I have a pcmcia slot, so man this is such a tough decision on what to get
thanks
Ron

jpschust · « **Reply #5 on:** December 18, 2003, 06:49:39 PM »

luvean, i disagree about pcmcia always being better, usb2.0 is just as fast and is way less a pain in the ass to be honest. there are many ua-5 tapes out there and they sound great. also it is powerable in the field.

nic · « **Reply #6 on:** December 18, 2003, 08:00:58 PM »

usb2 is no where close to the bus speed of pcmcia!
another issue to consider is that MOST usb2 controllers do not run at its highest speed.
did you know that there are 3 speeds for usb2? 1.5mbs, 11mbs, and 480mbs. they are labeled as low, full and high speed respectively...most of them(controllers and devices) are NOT "high speed". also even the highest speed of usb2 is only a theoretical peak speed...standard firewire has a higher _average_ throughput than the fastest usb2's _average_ throughput.

not saying usb/usb2 is bad, it isn't, but its more marketing than actual proven performance.
pcmcia is even faster and more stable than firewire400/firewire800....external scsi drives for laptops are based on the pcmcia interface

ropscot · « **Reply #7 on:** December 18, 2003, 08:09:47 PM »

ok so what do you recomend I found the firewire 410 for $330 or should I go with something like the echo layla and use a external mixer
thanks
Ron

nic · « **Reply #8 on:** December 18, 2003, 08:18:14 PM »

sorry about above...

pretty much any interface from the Edirol UA-5 to the Firewire 410 are good for what you will be doing. the MAudio unit is pretty new so the full field testing isnt in quite yet.
you will get the best results by mixing on the computer(you have more fine tune control) instead of a external mixer w/ headphones...for mixing on the pc, you want the interface to sent the audio channels seperately instead of mixing in the unit and sending a stereo signal to the system that you cant mix down later.

it really depends on your budget and how much gear you want to carry around.
my rig is mainly for archiving, I carry a 6U rack case(not exactly portable for the average show) and mixdown in post after the show

ropscot · « **Reply #9 on:** December 18, 2003, 08:44:44 PM »

sounds great to me I htink I will probally go with the firewire 410

F.O.Bean · « **Reply #10 on:** December 19, 2003, 07:16:03 AM »

good info luvean, +T bro...

Simp-Dawg · « **Reply #11 on:** December 19, 2003, 11:27:42 AM »

another option is the rme multiset, has 8 (i believe) analog inputs and spdif in/out as well. if you already have any outboard gear (pre, a/d) this may be a good option for you.
another option is the usbpre which i use to go straight from my mics to the laptop, does the pre and a/d all in one box and sounds great. downsides are it only goes up to 24bit/48khz and there's no digital outs while recording to your laptop, and the only analog outs while recording are the headphone monitors. but that's only a problem for patchers, although it ends up working out nice for the md'ers

jpschust · « **Reply #12 on:** December 19, 2003, 03:33:28 PM »

the multiset is a good unit but expensive. also the analog inputs overload like a mofo so you really have to watch the amount of gain you give them

tungstengruvsten · « **Reply #13 on:** December 22, 2003, 01:47:31 PM »

Quote from: jpschust on December 19, 2003, 03:33:28 PM

... also the analog inputs overload like a mofo so you really have to watch the amount of gain you give them

hmmm with a measured 110dB of dynamic range, i'd say you aren't gain staging properly. I've recorded 2 albums and many demos with these and used every pre from ART to Neve....never had a problem. must be a settings problem or whatever the piece of gear before it in the chain.

also, USB does not give a true 24 bits. hate to break it to ya folks but it's been proven. marketing lies go a long way unfortunately.

MattD · « **Reply #14 on:** December 22, 2003, 01:52:43 PM »

Technically, nothing I know exists that gives a "true" 24 bits. Our 24-bit A/Ds probably top out at 21-22 under the most favorible real world conditions.

I am curious as to what you mean by that statement, though. Do you mean that USB introduces noise in the lowest bit(s)?

Simp-Dawg · « **Reply #15 on:** December 22, 2003, 01:53:33 PM »

Quote from: tungstengruvsten on December 22, 2003, 01:47:31 PM

also, USB does not give a true 24 bits. hate to break it to ya folks but it's been proven. marketing lies go a long way unfortunately.

there aren't really any devices i know of that do true 24bit recording...i believe you'd need a full 144db of dynamic range which nothing really has at this point that i'm aware of. it's not just usb, unless you have some information to back that claim up.

tungstengruvsten · « **Reply #16 on:** December 22, 2003, 02:29:22 PM »

The problem with USB is in relation to the low power source, not the generally accepted difference of the 24 bit digital theoretical limit(144dB) and the real world of 110-120dB.

The best convertors i've used(mytek/benchmark/lavry) are up around 118dB which is f'ing impressive.

anyways, this from Dan Lavry - designer of some of the finest convertors ever:
-------------------------------
...In other words, 24 bits is not just about the digits we use. Some of
those digits are "just there doing nothing". It is like counting real money with 4 digits for cents. Instead of saying $1.27, we say $1.2700. The right 2 digits are always 00.

Now, lets go into the computers world, With 5V analog supply
environment, instead of the +/-15V above (equivalent to 30VDC). We
must reduce the signal range by about 6:1 and lose about 15.5dB in signal to noise...
Another 2.5 bits gone...

That too is a terribly optimistic picture. That 5V from the USB bus or
other port is so dirty, that by the time you clean it, you are
probably starting at 3.3VDC, not 5V... and you are entering the 16 bit performance world. Do not feel bad. Most CD's are less than 16 bits in terms of signal to noise, and some of them are great sounding!

But, don't spend your money on BS hype. 24bit USB device for $200? You can not get real 24 bits for $200000. For reasonably low cost, you
will do very well to really achive 16 bits.
-------------------------------

Simp-Dawg · « **Reply #17 on:** December 22, 2003, 02:40:05 PM »

i must say that's the first reference i've ever read to the power supply having any effect on resolution. not quite sure what to think about that.

MattD · « **Reply #18 on:** December 22, 2003, 02:45:08 PM »

That assumes you're using the USB to power your device, doesn't it? It seems like most people going out there with USB devices like the Mini-Me or UA-5 have their own means of supplying DC power. The USB cable/ports are only being used to carry the signal. Isn't standard SPDIF 1 V p-p?

-Matt

Simp-Dawg · « **Reply #19 on:** December 22, 2003, 02:46:12 PM »

fwiw the usbpre i use is powered solely off the usb port.

mirth · « **Reply #20 on:** December 22, 2003, 02:54:29 PM »

Maybe this is a limiting factor for bus-powered devices? We all know the UA-5 doesn't even power on with less than ~8V...

tungstengruvsten · « **Reply #21 on:** December 22, 2003, 03:11:05 PM »

Quote from: MattD on December 22, 2003, 02:45:08 PM

That assumes you're using the USB to power your device, doesn't it? It seems like most people going out there with USB devices like the Mini-Me or UA-5 have their own means of supplying DC power. The USB cable/ports are only being used to carry the signal. Isn't standard SPDIF 1 V p-p?

-Matt

not sure what everyone is running but I know lots of USB based ones that run off the USB power.

Also, spdif is a digital signal so it's voltage isn't really related.

mirth · « **Reply #22 on:** December 22, 2003, 03:12:31 PM »

How is USB NOT a digital signal?

tungstengruvsten · « **Reply #23 on:** December 22, 2003, 04:13:08 PM »

uh, wasn't saying anything was or wasn't a digital signal, i was saying we're talking about the voltage supplying the convertors, not the output voltage swing of spdif. Digital circuitry is perfectly fine at 5v, audio is not I guess is the distilled version of this...convertors are both, so they kinda sit in the middle. Audio op-amps and circuitry reflect the input voltage in their amount of available headroom ie dynamic range. That's why pro circuits use +/- 15 or 18v or the common one between Neve/Api/ most non-tube pre's is 24v DC.

Simp-Dawg · « **Reply #24 on:** December 22, 2003, 04:54:23 PM »

i'm really lost here...can you help explain the signal path to me?
what i'm getting is that with the limited voltage being supplied to, say, the usbpre, the analog circuits are not getting enough power to fully acheive the capability of the 24-bit a/d chip? even at it's limited dynamic range?
i'm struggling here...
by the way here is info from usbpre.com on the power consumption

Quote

Powering:

USB bus powered, 3 stage soft-start meets USB hot-plugging power requirements
5 V, 100 mA max current drawn during enumeration
5 V, 250 mA quiescent current from USB port
5 V, 500 mA max current from USB port

Brian · « **Reply #25 on:** December 22, 2003, 05:55:36 PM »

Quote from: Simp-Dawg on December 22, 2003, 01:53:33 PM

Quote from: tungstengruvsten on December 22, 2003, 01:47:31 PM

also, USB does not give a true 24 bits. hate to break it to ya folks but it's been proven. marketing lies go a long way unfortunately.

there aren't really any devices i know of that do true 24bit recording...i believe you'd need a full 144db of dynamic range which nothing really has at this point that i'm aware of. it's not just usb, unless you have some information to back that claim up.

FWIW josh is right. When we all record at either 16 or 24 bit we really aren't recording at those EXACT bitrates. When recording at 16bit it is more like 14bit and when we record at 24bit it's more like 18bit even at the highest possible recording levels.

same thing goes with pixelation in digital cameras. whatever pixel value the camera says it is, divide that in half and that is your true pixel rate.

as tungsten said....all marketing lies unfortunately. here's to hoping for true 24bit one of these days!

Brian