Need help using a preamp with Echo IO card

Oh wow, you want an entire lecture on gain structure...

To properly teach you this could take a while, and by a while I mean a LONG while. There are pros out there I have come across that still dont understand this, though it is key to getting the best quality audio you can... Ill try to give you a summarized version, but I would strongly suggest googling gain structure in the studio and doing some independant research as there will rpobably be things I leave out as I dont have an entire class to teach you this.

Understand also I am not to good at explaining things

First things first..

GAIN and VOLUME are NOT the same thing.

Gain is the amount of input signal that you listen to. For instance if you are feeding a VERY strong signal into something, you can choose to not lsiten to so much and you will have a weaker signal transversing the device. This is useful because each electronic circuit has a limited amount of signal it can take without overloading. Overloading in digital audio, also known as clipping, as VERY bad and makes you sound awful, in analog audio it isnt so bad, and can be gotten away with or even used for effect(Carefully), in digital audio it just puts everyone in a lot of pain. It will sound(As best as I can describe) like cracking at high volumes.

Volume as it is often used is actually a method of amplification. It takes the input signal, and amplifies it to whatever level you want. In the case of preamps this is typically a straight amplification, and gain will be the only control adjustable, but mixing consoles have both.

Proper gain(In VERY brief) structure involves setting your gain properly so you get the strongest signal coming into a circuit before amplification that you can, without clipping it. The reason for this is because digital circuits and amplification can(And do) add in their own noise, so the less amplification you need the less of that noise you will get. Thus the cleaner sound you will get.

Now on to your specifics.

These two are tied directly together. The switch control which range of values you are using on your gain, the +26-+60 or +6-+40. With the switch in the off position you are using the +6-+40 range of values on your gain, with the gain in the on position you are using the +26-+40 range of values.

The reason for this, typically, is to allow you to hook up stronger signals into your pre without clipping the signal. Again follow the rule above, use the amount of gain that gets you a strong signal without clipping. This will range from input source to input source.

The SM58 does NOT require phantom power. HOWEVER Condenser mics do. Condenser mics are typically what is used in recording due to having a more accurate frequency response, and are made differently from Dynamic Mics which are used more often on stage. These are both VERY generalized statements and depending on the application there is a LOT of crossover between the two.

There are I think 2 Dynamics that require phantom power, one of them is by blue, I thought I saw another out there but cant remember right now. However those are exceptions to the rule, and very rare exceptions at that.

So in the current setup you have, leave this switch off. If you turn it on as long as nothing is wrong with your mic it shouldnt harm anything, but it is better to have it off if you dont need it.

With a single mic you will never need to worry about it. It is actually a POLARITY reverse switch(Not phase, but the two terms get used interchangeably a lot) and essentially flips the 2d visual representation of the sound wave(Think Sine Wave) over. It is used in cirtcumstances requiring more than one mic where you might get bleedthrough, or in some instances to help with feedback. I am sure there are others I have forgotten about but those are the two most common. Again with a single mic you wont ever have to worry about it and its position doesnt really matter to you, but it probably is good practice to just leave it off.

This it the volume, seperate from the gain. The only reason you would want this to be on anything other than no amplification(Should be marked as +0dB, but it CAN vary from manufacturer, what is the total range on this?) otherwise known as unity gain, where nothing is added or subtracted from the signal, is if you have a strong signal going into your preamp(Aka gain set correctly) but yet the signal into your laptop is either weak, or clipping, then you COULD use this control to allow for the same quality signal going into the laptop. Though if you have a gain availiable on the laptop it is typically better to use that instead as that way you are not running through any amplification stages, and thus adding a little noise. There are exceptions of course I would imagine, it depends on the quality of amplification availiable on both the pre and the laptop sound card, but in general this will do you good.

See above. If this question isnt answered to you yet then ask.

Seablade

Thank you, very informative! As to your claim of not being able to explain things well I say BULL**** you were very clear and helpful. Again thanks, people like you are what make forums so good.

Ok somewhere in that entire line should be a level that reads 0. That is your unity gain, where no amplification or cuts happen. Ideally you want it to rest at this point.

Just to clarify this range for oyu a bit. The -infinity point is where essentially you get nothing, there should be no signal passing through it as it is cutting all signal. The +10 point is amplifying your signal another +10dB over what it currently is getting from the preamplification stage. 0 as I said is unity, where no amplification or cuts are happening, and is where you ideally want things to rest.

Yes on all accounts.

Now you will get noise with your gain as well, as all electronic circuits will induce noise, and in particular because your Pre is not a truly high end pre. That means that increasing the gain will increase the amount of noise as well(Though less than the amplification on the output will), but in the end you want to have stronger gain and your output fader resting at 0 if possible. Again set the gain so that you get as strong a signal as possible and adjust the output volume if needed.

If you have the gain set correctly on the Pre(As high as you can get it without it clipping) then this would probably be your best bet yes. Again setting the gain first is the most important. If you get a lot of noise doing this what you may want to try is recording with the output at 0 again and using a DSP process to amplify it. If the amplification stage on the output of your pre is particularly noisy this can sometimes provide better results, but most of the time wont with a decent amplification.

Also you should check to see what input voltage your Echo is expecting, and what output voltage your Art is providing. There is a difference between consumer levels and professional levels (-10 dBu vs +4 dBu) and if you get a mismatch between them that can cause significant effects on your signal. As such you should try to make sure they are identical.

Seablade

DSP=Digital Signal Processing.

In other words, use a software program. Again most of the time this is not the way to go, the only reason to do this is if the final ammplification is REALLY noisy. If you are getting a good signal, stick with it, a couple of rules of thumb in audio....

If it aint broke, dont fix it.

KISS- Keep It Simple Stupid

Keep em in mind

Seablade