Microphone Preamps - Are They Needed If You Have An Audio Interface?

[miketurn]

Hello Everyone,

In my thread concerning microphones, a couple people have been mentioning that a preamp that is separate from my audio interface preamp is needed.
Seems that some agree with this and some don't.

Apparently microphones such as ribbons, dynamic and broadcasting dynamic mics require more power to get them to work properly. Some even say that condenser microphones will also see an improvement from separate preamps as well.

Personally I would hope that I could avoid an extra piece of gear like this for my own personal setup, but it does lead me to some questions.

1.) Do typical USB2 powered (no external power adapter) interfaces of today (2017) have the preamp power needed to use these microphones properly?
Dynamic (Example: SM57 and SM58)
Broadcasting Dynamic (Example: SM7B and Electro-Voice RE20)
Ribbon

2.) If so what are some proven USB2 powered audio interfaces (with no external power adapter) that can achieve this?

3.) I had originally thought that it was just higher quality broadcasting dynamic microphones that require this additional power, but it seems that some say that regular dynamics, specifically the SM57, requires a great deal power as well, only slightly less than the SM7B, is this true?

Ideally I would hope for some answers on my specific situation above, but eventually I am okay with this thread becoming more broad so that others can benefit from it as well.

Thank You

[ghettosynth]

Just to clarify a few terms. The preamp needs gain, which is related to the capabilities of the "power supply." So, while "power" can be the limiting factor in some cases, it's a bit of a misnomer here. You want to talk about clean gain given the limitations of the power supplied by USB2.

You should link to pages where people are talking about this so that it can be put in context. IMNSHO, SM57s and SM58s have been used on everything ever made and so I find it a bit of a dubious claim that they need more gain that is typically available in a modern USB2 interface.

[Hermetech Mastering]

No, you don't NEED one, but a great pre will make all the mics you use it with shine.

[ghettosynth]

No, you don't NEED one, but a great pre will make all the mics you use it with shine.

You know, I have not found this in my past experiences. However, there are other things that I've become more sensitive to over time so I'm trying to keep an open mind about this.

Can we have a conversation about preamps, in general? Maybe just start with a couple of recommendations of good preamps that are in OPs general budget range, maybe push that a little bit, and then talk about how you think that makes the mic shine?

[Hermetech Mastering]

I've only used the TG2 for the last ten years and it's consistently made any mic I've used with it sound great. Before that I only had access to crappy Mackie desk pres, the Chandler was a huge step up. Hard to describe, and as I said, I have not used anything else for a decade, so undoubtedly I am blinkered, but it just makes shit sound right.

It's a lot to do with clean gain and headroom I think. The SM57/58/7B all need around 60dB of gain, and with a lot of crappy pres that's maxing them out and the analogue electronics will be pushed due to the lower power voltage rails, and it therefore might sound pushed. It'll work fine, just might not sound as good as it could.

Same thing with headphone amps, no one needs one, but it'll undoubtedly make your cans sound better. If the OP is looking for a mic, then get a mic. Can worry about better pres later, they don't come cheap.

[skipscada]

Very relevant article re spending lots of money on a preamp: http://www.soundonsound.com/reviews/pick-preamp

Since then, preamps in audio interfaces have only become better, and if you have a recent, decent audio interface, it seems unlikely that a preamp is the best investment you can do.

Many dynamics and most ribbons can benefit from a preamp-before-the-preamp like Cloudlifter since the typical gain provided by a preamp can be on the limit of what's needed when recording quiet or distant sources. You will know when you need one.

[ghettosynth]

I've only used the TG2 for the last ten years and it's consistently made any mic I've used with it sound great. Before that I only had access to crappy Mackie desk pres, the Chandler was a huge step up.

Ah, ok, well, that sort of explains it then. It's almost certainly the character of the EMI TG12428 preamp that matters here. Of course, that's a $2K+ preamp, so it's not the kind of thing that the OP can probably justify. I know that I can't. Still, I might try just DIYing something from the character department and see what it does for me.

[ghettosynth]

Very relevant article re spending lots of money on a preamp: http://www.soundonsound.com/reviews/pick-preamp

Awesome, that mirrors my own experience as well. Not that I have ever experienced that kind of quality, however, if they can't tell the difference between really expensive pres and the VLZ, then I suspect that there's little hope for me to be able to tell the difference between a preamp that I can afford and those in my mid-range interface (MOTU Traveler MK3).

I have an Altec 1589 and as much as people go on about that thing, it's never seemed worth the hassle to me. I have a bunch of the preamp modules for it so I could conceivably recap them and make them as clean as possible.

It's also fairly easy to add some character these days with plugins. I really like Waves NLS on the EMI setting, for example.

[TheRogue]

I think it really comes down to the quality of the preamps that are built into the audio interface. RME and UAD for example provide more than average quality so in such cases an extra device would not really be required unless one would want to go for ultimate quality.

[transmetropolitan]

If you've got a mic pre that will give you about 60db of clean gain, then you have something you can fruitfully use with almost any mic.

If your mic pre does not do this, then you are more restricted in your microphone options. The SM7 is a classic example - one of the best affordable mics bar none but it does need a lot of gain.

Boutique style pres do make a difference, but it's not a massive difference. Though I'll add - I find they generally make a bigger difference with a lesser mic.

World class pres start at the cheaper end with brands like Daking, which is based on the old Trident Class A design.

A step down from this is something like the Warm Audio API 312 clone.

I wouldn't recommend upgrading from your interface pres for anything less than this on the presumption that you have enough gain on hand to record dynamics and ribbons well.

[ghettosynth]

So I downloaded the files from that article and, for me, at the moment, it confirms my past experience. I'm sure that I couldn't tell the difference between any of those files in a blind test. I used the Royer mic samples as it is a ribbon and should be sensitive to gain and impedance differences.

[miketurn]

Thank You all for the responses,

So from what I understand, if you have an audio interface that has at least 60db of gain then you don't need a preamp, however a preamp apparently can make most microphones sound better to some.
Many use the phrase "clean gain" meaning that it isn't just about having 60db of gain, but what it sounds like to me is that it has to have more than 60db of gain, because if your audio interface gain is maxed out at 60db, it most likely is not going to be clean. Not saying that this is true, but it just sounds like that is what this means to me.

So confused.....
1.) What is the EXACT spec one would have to look for about an audio interface in order to determine how much preamp gain it offers?
2.) How would you know if an USB2 powered audio interface offers 60db of "clean gain"?
3.) If the SM7B is such a great mic and so many people have them, how come it is such a mystery piece of gear?
4.) Seems that most who have an SM7B say they have a Cloudlifter, nobody out there is just using an SM7B with just an audio interface? No one out there has a powerful enough audio interface to do so?
5.) I have not been able to find any information about a single USB2 powered audio interface that could provide the gain needed for a SM7B, does anyone know of specific model interfaces that can?
6.) (Dynamic Mics) SM57 seems to be said to need 54-60db depending on who says, has anyone hooked one of these up to a USB2 powered audio interface and been able to get good vocal results with it?
7.) Hard to say without knowing some of the information from the questions above, but WITHOUT a preamp or Cloudlifter, would purchasing a broadcaster dynamic mic such as the SM7B, RE20, etc. be a waste? Is their magic based on a high quality extra preamp?

As I mention, I personally would NOT get a preamp at all, a big part of all of this for me is to start to rule things out. I am not saying I am going to buy an SM7B or a RE20 but I am using them as examples because they seem to be the most gain hungry and they are so highly regarded.
Just trying to start narrowing some things down, and spending about $1000 to realize that I can't sing, doesn't sound like a good idea to me at the moment

[ghettosynth]

7.) Hard to say without knowing some of the information from the questions above, but WITHOUT a preamp or Cloudlifter, would purchasing a broadcaster dynamic mic such as the SM7B, RE20, etc. be a waste? Is their magic based on a high quality extra preamp?

A cloudlifter is really just a small phantom powered preamp, FYI. Did you listen to those audio files?

[BertKoor]

if your audio interface gain is maxed out at 60db, it most likely is not going to be clean.

No, that's a too bald statement. Clean means no distortion, and distortion has no direct corellation with the gain factor. You can max out the gain trim pot without getting distortion: as long as the input is low enough, the output of the preamp won't distort. Only if the output level of the preamp goes above it's maximum (the clipping level) then you get distortion.

1.) What is the EXACT spec one would have to look for about an audio interface in order to determine how much preamp gain it offers?
2.) How would you know if an USB2 powered audio interface offers 60db of "clean gain"?

You pull up the tech specs, usually at the end of the owner's manual. There it should state the gain factor in decibels.

As I mention, I personally would NOT get a preamp at all, a big part of all of this for me is to start to rule things out. [...] Just trying to start narrowing some things down, and spending about $1000 to realize that I can't sing, doesn't sound like a good idea to me at the moment

The best advice I can give you is look for an interface that has both a regular line level input (preferrably balanced) and also a transparent mic input. You can then start with the built-in preamp, and get a separate preamp later.

[NukeArts]

I only have one experience: Brauner Phantom Classic with RME built in preamp vs. Avalon SP737.
This is such a huge difference that it is barely describable.