Why do I need a pre-amp?

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glynb

Balladeer
I am using a Fostex vf160 Multitracker.

I input all my instruments directly (guitars both acoustic and electric with effects pedal, keyboard, synt drums from the keyboard, electric bass etc ) and input the vocal mic directly which although I have to crank it right up I still manage to get a hot enough signal. I have a compressor which I use.

People keep saying we should all have a pre-amp as a basic requirement, but why? I seem to be getting reasonable results without one. What extra would a pre-amp give me other than a hotter signal on the vocal mic?

I am open to persuasion, just not been persuaded yet!
 
With your set-up, you only need a pre-amp for the vocal mic.

Although you may be able to crank the gain of a line-in circuit high enough to make the mic work without a pre-amp, you're ignoring the the fact that a pre-amp input impendance is set up to closely match the output impedance of a mc.

Impedance matching is very important when transferring an audio signal from one source to another. It's basically assures that the signal is transferred with a minimum of distortion. Distortion occurs because a small amount of the transmitted signal is constantly being reflected backwards to the source.

When you don't pay attention to impedance matching, you are likely not getting an accurate representation of the original signal into your system.
 
You need a mic preamp to amplify the weak microphone signal to line level. Yes, it's a basic requirement, no, you can't do without them.


Luckily for you, you have preamps. Eight of them, in the VF160.
 
Now I get it...

Ah, I see. So the 'must buy a pre-amp' rule is aimed mainly at PC recording I assume, and they need a pre-amp prior to going in to the PC soundcard, now it makes sense.

I tend to forget that the majority of people are using a PC to do their recording not a multitracker.

Thanks for the explanation.
 
Yo glynb! Every mic needs a preamp, and your standalone has some. In general, however, the pres in standalones suck. By using a good clean preamp for the front end of your VF, you will get a hotter signal with less noise and distortion, which equals better sound. I use a standalone also, a Roland VS1824CD, but I feed it with an Avalon AD2022, a Joemeek twinQcs, a DBX386, and a DMP3. Go figure.-Richie
 
Noise and distortion?

I haven't really noticed any noticable noise and or distortion, even when boosting the input right up for the mic (Sure SM58).

But maybe I am just easily pleased, or just lucky! The only time I've noticed noise is when I use my keyboard through a guitar effects pedal and compressor!

No doubt the noise 'is there' in the recording I hear you say, but if you can't really hear it what does it matter? I'd be worried about introducing so many devices to the chain before it gets to the recorder for precisely the reason that it may introduce additional noise as the signal passes through so many devices!

But no doubt you know exactly what you're doing, unlike me!
 
After looking at your unit on the web, I think I see what's going on...

I think you are actually using one of the internal pre-amps and don't realize it. If you are plugging your microphone into one of the XLR jacks it's going through a pre-amp.

yez/noh?
 
I don't see any way to fully bypass the VF's pres when you use an external analog mic pre with the VF. As I understand it the signal still has to go thru the built-in preamp even though the trim pot is turned fully counter-colckwise to unity gain.

Wouldn't the quality of the built-inpre still affect the sound in this case also?
 
I'm assuming his unit has line inputs as well as mic inputs, so you'd have to connect the line-out of the external pre-amp to the line-in of his all-in-one unit.
 
Re: Noise and distortion?

glynb: If the preamps sound good to you, then they sound good, period. Don't get fooled by any gearsluts into buying something you don't need. The best gear acquicistion strategy is to only buy that which you have to buy to get the sound you want, and only replace gear you feel that is killing your sound.
 
Phyl said:
I'm assuming his unit has line inputs as well as mic inputs, so you'd have to connect the line-out of the external pre-amp to the line-in of his all-in-one unit.

Probably not. It's unusual in most budget gear, and in all honesty, it's not much of a problem. On some gear you can bypass the micpre/trim part of the mixer by using the inserts, if you really want.
 
When a previous poster noted that with Built in pre amps you get noise and distortion he/she was right on. You are getting noise and distortion but its not crazy fuzz box type distortion the best way to understand this is to be in nice studio with a great singer. The difference is night and day. But a good preamp can cost $2500-$25,000 and is not neccesary in your project studio. I don't use any except the ones that came on my digi002 rack.
 
Noise from cheap pres becomes a bigger issue the more tracks you lay down. The noise floor on a 4 track recording that's acceptable can become quite brutal at 12-16 tracks.-Richie
 
Yes XLR slot

I plug the sm58 into one of the two XLR slots on the vf160. But to be honest i used to plug it into the jack sockets too and didn't notice any difference in response. So like someone said, i think there are pre's on all the 8 inputs not just the xlr's.

yes, as i suspected for higher end recpording then expensive pre-amps are high on the shopping list, but for a budget recording setup like mine I guess the VF160's pre's will do.

I any case I think a condenser mic is top of my shopping list and I've been advised would give me more bang for the buck compared with a sm58.

Trouble is the more you learn about this home recording scene the more you realise how inadequate your setup is and how that one more piece of gear might make the difference!

I don't want to go down that route too far. My view is that if your songs are great and the recording is 'adequate' that's a better position to be in than adequate material with a superb recording!

Not that I'm arrogantly suggesting my stuff is great, but if it isn't then a better recording isn't going to make much difference!
 
Glynb, you're going to be fine. Start with the music and the room, and go from there. Don't doubt that there's almost nobody who doesn't need a preamp, maybe even Fletcher.-Richie
 
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