Really Really basic info in PRE'S

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sessionselect

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Ok, this may sound stupid but that's what this forum is for.....
now, when you plug into a pre, then go through a mixer or a soundcard with pres in it, does it just bypass the built in pres in the mixer and soundcard? And if it doesn't, what's the point?
Or maybe i don't know how the chain works with an external pre.....some fill me in please


ss
 
Ideally, you'd want to run the external pre into one of the sound card inputs that doesn't have a pre. The mic inputs will have pres, the line inputs should not. Using the line input is the only real way I know of to "bypass" the pre on the mic input :)

External pres are good because you can use a different pre depending on your mic, source, mood, etc.-- you won't be limited to the sound card pre.

Also, low-end soundblasters and such tend to have rather crappy pres. Only use the line input if that's your card--in which case external pres become very necessary.
 
what about when you're going through a mixer and you're using the mixers pres......how do you use an external pre with a mixer?
once again...very basic

ss

also, if you used an external pre on say the mix input on a sound card with built in pres, what will that do
 
To use an external pre with a mixer, send the external pre's output to one of the line ins (the 1/4" jack input, not the XLR [three pin] input). Use a channel that doesn't have a pre. (The channel fader doesn't count as a "pre".)

The "stereo" channels on small Behringers, ferinstance, won't have pres-- plug the external pre into the "left" input for mono usage. On Behringer channels that include preamps, the 1/4 input does go through the pre. Check your mixer's schematic diagram to be sure where everything goes.

I don't know what you mean by "mix input" (I have limited experience with sound cards). If it's a line input, it shouldn't have a pre on it. Check with the manufacturer to be sure. What kind of card is it?

Generally, if you don't have a nice expensive audio recording sound card, you don't want to use the pres on it.
 
oh sorry, i didn't mean "mix input" i meant mic. the only deal is, i have a cport dsp 2000 with 8 1/4" inputs and 2 xlr inputs with preamps.
and seanmorse79 has this card(mines coming in the mail) and he said the preamps on the card aren't that great. But i want those extra 2 channels to record simultaniously with the other 8. So i was wondering if there was a way to "clean up the pres" on the soundcard.....

thanks

ss
 
Hmmm.... the only thing I could think of is maybe keeping the card pre's levels down as low as possible. Basically trying to keep the preamp's character (the character you don't want, in Sean's estimation) out of the way of the signal that you have to pass through it. Maybe Sean has a suggestion?

Also, you could use the two questionable card pres for the tracks of lowest importance to your mix. If something can suffer a little in the fidelity department, run it through the card pre. Maybe you'll like the sound of those pres for something, who knows? Play around with it and see what you get. A ten-input card sounds like a fun toy--enjoy it! :)
 
"if you used an external pre on say the mix input on a sound card " - Sounds like you mis-read the label and could be talking about a "mic" input. If that's the case, you would NOT want to use that input on your sound card.

Sound cards that are one piece and mount in a slot inside your computer are almost ALL too noisy to use with mics connected to their mic input. The main reason for this is that computers generate LOTS of electrical noise, and it's nearly impossible to keep that noise from getting into an audio signal that is as weak as an un-amplified mic signal.

So, the first thing to do to improve the noise level is to amplify the mic signal BEFORE it gets close to all that computer noise, and that's what a pre-amp ("pre") does. A typical pre raises the level of a mic signal by at least 40 dB, which is a voltage ratio of 100 to 1. This means that after going thru the pre, the mic signal is now 100 TIMES as strong as it was. This means that when the signal gets into the computer, it picks up roughly the same amount of noise, but since the signal you WANT is so much stronger, you don't hear anywhere near as much noise.

outboard pre's can be used with only a sound card if you have no mixer or really want to minimise the amount of circuitry the sound goes through so you get the cleanest possible sound.

If you want nearly as clean a sound but need the flexibility of being able to route things and hear what you're doing, then a mixer becomes necessary.

When using a mixer with a separate, outboard pre, as mentioned above you need to make sure the pre is connected into a LINE level input, NOT a MIC level input. This is because the pre has already boosted the signal by about 100 times, and if you take that already boosted signal and connect it to ANOTHER pre-amp, such as the ones in a mixer, you will cause it to distort due to 'way too high an input level.

So, if you're using an EXTERNAL pre-amp into a Behringer mixer or any mixer that also feeds its 1/4" inputs through the mixer's own INTERNAL pre-amp, you need to find a way to by-pass the INTERNAL preamp. This can sometimes be done by a mic/line switch if there is one, or by using a line input (check the schematic as mentioned earlier) - sometimes you can use a channel INSERT point as a line in, but you will probably need a slightly different cable or adapter, and may lose some functions on that channel when connected that way.

Read this again, slowly, and c'mon back with the other 142 questions it'll bring up... Steve
 
well the thing is i'm using the mixer's preamps (via the insert) to go into the 1/4" jacks on the external breakbox of the soundcard....and i have a Mackie CFX20 so every channel has a preamp, i'm not sure about the stereo channels though....i'll have to check..
 
Usually on a 'real' mixer there are line and mic inputs on every channel. I'm 90% positive that is the case with that Mackie. You can also use Tape In and Aux returns as line inputs if needed.
 
"Sometimes shorter is better.
" - STILL tryin' to convince my wife of that...
 
Not stupid

Actually, that's not a stupid question at all.

So far as I can tell, a lot of people hook up outboard preampss to mixer inputs which result in the mixer padding the signal down and running it through another preamp. I even read a post on a newsgroup once where a guy wrote a detailed analysis of the the perceived sonic differences between an outboard preamp and the Mackie pres in his mixer, after hooking up the outboard this way.

If you're going direct to a soundcard (which would seem to be the sensible way to go, if you're recording to the computer), I guess the answer really depends on exactly how your soundcard is put together. Even a supposed line level input might just pad the input and run it through the mic pre.

Lots of mixers (but not all) do exactly that: though they have both XLR "mic" inputs and 1/4" "line" inputs on each channel, they all go the same place (except, often, there's a pad in between on the 1/4" input). If you're using such a mixer, possible places to input a line-level signal are: channel inserts, tape returns, channel strips without a mic pre at all (usually stereo inputs don't have a preamp), effects returns, "sub" inputs.
 
i'm not sure if you guys are understanding what i'm saying, but i'm probably not explaining it well either...

ok......here's my chain

MIC -- MACKIE(through xlr input) --- Soundcard (from insert on mackie, to 1/4" input on soundcard breakbox).... that's it...short and sweet..........sometimes shorter is better....well, in this case


my question was......i have 8 1/4" inputs on the soundcard...and 2 xlr inputs with built in pre amps......can i use an external pre amp then go into the 2 built in pre amps to make it better(i heard the pre amps built in suck)

thanks
ss
 
sessionselect said:
my question was......i have 8 1/4" inputs on the soundcard...and 2 xlr inputs with built in pre amps......can i use an external pre amp then go into the 2 built in pre amps to make it better(i heard the pre amps built in suck)
Click to expand...

Yes you can but that is not the best way. Going into the 1/4 line inputs would be cleaner.
 
... I think Mackie has a very good preamp. Warm, bright & nice gain level. IMHO although possible, you don't have to use any outboard preamp with Mackie for average result :). BTW, what is your external preamps?
 
well the only reason why i wanted to use the sound card's channels with built in pre amps is because with the extra two pre amped channels........i can record 10 channels simultaniously, which is ideal for what i want to do. so i have 8 1/4" inputs and 2 xlr inputs on the soundcard. How can i clean up the built in preamps?
 
sessionselect said:
the only deal is, i have a cport dsp 2000 with 8 1/4" inputs and 2 xlr inputs with preamps.
and seanmorse79 has this card(mines coming in the mail) and he said the preamps on the card aren't that great. But i want those extra 2 channels to record simultaniously with the other 8. So i was wondering if there was a way to "clean up the pres" on the soundcard.....
Click to expand...
What do you want to do with 10 chanels at once ? Drums tracking ?
I think there's nothing much left for you to do to fix it... Usualy (... not always ) built in preamps come with soundcard ain't doin that good. So, the only way is to feed lower priority signal ( ...Hihat or cowbells perhaps ) into these 2 extra input. Which won't be that critical important, and hard to edit in mixing section later. :D
 
sessionselect said:
How can i clean up the built in preamps?
Click to expand...

You can't, AFAIK, without physically altering your sound card's electronics...

Check out the pres when you get them. They might not be as bad as you think they are. If they DO suck, keep the card preamp gain as low as you can, using the Mackie or another pre to get your gain. This should avoid most of the sound card preamp's sound, as preamps tend to be cleaner when run at low levels.

Or, like James Argo and I mentioned earlier, use the card preamps on your lowest-priority tracks, like the tracks you'd generally have to EQ a bit and set low in the mix anyway...

Good luck!!
 
...sorry to join in late on the topic - it's been a busy weekend :)

sessionselect, I've been in EXACTLY the same boat as you're in (except that you have a better mixer, you prick (just kidding) :)

Unfortunately, esactun is dead on. There's no way to avoid the pre's on 1 & 2 - I've talked to that German guy (can't remember his name) at ST-Audio - it just can't be done.

Don't get me wrong though, the channels are not worthless.
If you keep the pre's low and use them for the least prominent tracks (like esactun said), they you'll be fine. They do add a bit of midrange-ish color, but it's not horrible.

Test it out a bit and see what you think. I tested vocals and distorted guitar. They definitely colored the vocals, but it was pretty hard to tell the difference on the guitar tracks.
 
thanks a lot for the feedback, and yes i am gonna be doing drum tracking on it (9 mics...for recording at home but live it will only be 4) so i'll need all 10 channels. I was thinking i could just use one of the preamps on my floor tom which i don't use as much as my other toms and run a scratch bass or vocals thought the other pre. Then redub everything over later.

thanks

ss
 
...just out of curiosity, what are you using for the digital inputs of tracks 9 & 10?
 
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