The Value of Mic Preamps

[sentinel72]

I've read about some audio interfaces having better mic preamps than others.

Or even high end stand alone mic preamps.

A question: When it comes to mic'd gainy guitar tracks, how noticeable is it to use a "nicer" mic preamp vs something like a Mbox 2?

Does anyone have any A/B comparisons where everything is the same except the mic pre? No knob twiddling in between takes. Just crap pre vs nice pre.

Thoughts?

 

[sentinel72]

I can already sense the smartass replies coming...

Let me clarify ahead of time.

YES I know that the mic preamp will play into the sound from a mic.

I'm not assuming the crappiest preamp out there vs high dollar ones.

I'm assuming the ones in the mainstream audio interfaces. Mboxes, Fireboxes, Lexicon devices, Alesis units, Tascam devices, etc.... You know, the $100-$600 stuff.

And again, we're talking gainy guitar amps that are mic'd. Traditional metal fare.

GAINY GUITARS ONLY.

 

[if6was9]

Well I've been just using the ones in my Firepod but it was like night and day when I went up to Mickrich( Mick- trackmix in Dublin). He had some really nice phoenix audio and Focusrite ISA preamps that sounded great on guitar- everything had an extra depth and nice character to it.
Biggest improvement was when he used an audix I5 on my singers vocals- I've used that same mic on my singer before and he sounded 10X better with the nicer pre's. Mick said the mic pre can often make more of a difference than the mic itself being used. While that might be exaggerating a little it certainly makes a huge difference.

Edit: Just saw your new post. From what I've seen it makes a big enough difference to justify the cost on guitar. You can get an ISA one for about 600 euro? UA make a similar product in the same price bracket. If you're just using the 1 mic on your guitar you might aswell get the best sound you can. I've been tracking DI's for my bands upcoming album, planning on renting a really nice preamp for a weekend to re-amp the guits and bass instead of just using the Firepod's pre's

 

[colonel kurtz]

the type of mic pre isn't going to matter a whole ton on high-gain guitars

pres are much more important with vocals, acoustic guitar, etc. etc.

 

[Trevoire520]

Personally I think the impedance of the mic pre has alot to do with it.

Dynamic mic's tend to prefer lower impedance mic pre's, particularly SM57's/58's. But most cheap interfaces haave an input impedance of 2Kohms or more.

I just got a Mackie Onyx 800R which has switchable impedance on the first 2 channels (2.4K ohms, 1.8K ohms, 500 ohms & 300 ohms) and I found it to make a massive difference to the sound coming out of the mic. Going to a lower impedance decreases the level coming from the mic quite a bit. But once I had it level matched I found that the lower impedance settings seemed to be much more full range compared to the higher impedance's.

 

[JonWormwood]

Personally I think the impedance of the mic pre has alot to do with it.

Dynamic mic's tend to prefer lower impedance mic pre's, particularly SM57's/58's. But most cheap interfaces haave an input impedance of 2Kohms or more.

I just got a Mackie Onyx 800R which has switchable impedance on the first 2 channels (2.4K ohms, 1.8K ohms, 500 ohms & 300 ohms) and I found it to make a massive difference to the sound coming out of the mic. Going to a lower impedance decreases the level coming from the mic quite a bit. But once I had it level matched I found that the lower impedance settings seemed to be much more full range compared to the higher impedance's.

I just checked my VTB1 and it has 200 and 50 ohm options. I see some tests about to happen.

 

[JeffTD]

The biggest differences you'll get with nice preamps will be apparent when you start layering them and then drop them in the mix... it's almost stupid how much easier and cleaner it happens.

 

[sentinel72]

The biggest differences you'll get with nice preamps will be apparent when you start layering them and then drop them in the mix... it's almost stupid how much easier and cleaner it happens.

when you start layering guitar tracks?

Dynamic mic's tend to prefer lower impedance mic pre's, particularly SM57's/58's. But most cheap interfaces haave an input impedance of 2Kohms or more.

Yep, I just looked up the pre's in my mixer... 2.6 k Ohms

I have a Mbox2 also... Not sure what it is. Does one of these specs tell us?

Analog Ins
Separate source selection and gain control per channel
Mic: XLR with 48V phantom power
Mic preamp: >120 db EIN @ > 50 dB gain
Line: 1/4"
DI: 1/4"
Maximum Input: 8.7 V RMS (balanced), or +21 dBu


A/D
Sample Rate: 44.1, 48 kHz
Dynamic Range: 106 dB (A-weighted), 103 dB (unweighted)1,2
THD+N (line input): 0.00079% (-102 dB) @ 1 kHz1,3
THD+N @ 40 dB gain (mic input): 0.006% (-84 dB) @ 1 kHz1
Mic EIN (unweighted): -120 dB @ 40 dB gain, 150 ohm source
Frequency Response: +0/-0.5 dB, 20 Hz – 20 kHz3
Maximum Input: +21 dBu
Input Impedance (pad off): Mic=3.5 kOhm; Line=10 kOhm; DI= >1 MOhm

D/A
Sample Rate: 44.1, 48 kHz
Dynamic Range: 106 dB (A-weighted), 103 dB (unweighted)1,4
THD+N: 0.003% (-90.4 dB); -1 dBFS @ 1 kHz1,3
Frequency Response: +/-0.5 dB, 20 Hz – 20 kHz3

 

[sentinel72]

and here is the spec on a SM57

Impedance
Rated impedance is 150Ω (310Ω actual) for connection to
microphone inputs rated low impedance.

Yeah, doesnt look like my mixer or my mbox2 is a good mate for this mic.

 

[iHate]

The biggest differences you'll get with nice preamps will be apparent when you start layering them and then drop them in the mix... it's almost stupid how much easier and cleaner it happens.

This, but also this will only have a really big effect when the AD converters are great. If you plug a $1200 preamp into a firepod, it will probably sound a little better than the firepod, but not nearly as good as plugging it into some higher level converters.

 

[sentinel72]

this guy didnt hear an audible difference in using a beta 57 at low vs higher impedance.

http://newsgroups.derkeiler.com/Archive/Rec/rec.audio.pro/2007-05/msg02027.html

I'm interested in what you find out Necromancer197666.

 

[Kazrog]

The biggest differences you'll get with nice preamps will be apparent when you start layering them and then drop them in the mix... it's almost stupid how much easier and cleaner it happens.

+1

Also, don't worry about the integrated preamps on interfaces. Get a good interface with good A/D converters like a FireFace or ProFire, and go with a killer mic pre unit like an FMR RNP, API 3124 or a Vintech Neve clone if you want to get the best out of your mics. Obviously this starts getting pricey - but what you get for that price is hours of saved time and far better results.

 

[Metaltastic]

Gotta voice my skepticism on the importance of preamps; better ones will certainly help, but I've heard so many awesome tones (both solo'ed and in full mixes) on here recorded through Firepods, Profires, etc., that I'm certain good tones can be had with average pres; in other words, I highly doubt any problem one hears in his tone is gonna be solved by getting a better preamp! (as opposed to new/different guitar/amp/cab/mic/etc., things that matter WAY the fuck more)

 

[Trevoire520]

Yeah I will agree with Marcus in that pre's are really low on the scale of importance. Though obviously I'd rather be using an API pre than a pre from a Behringer mixer!

Really the things that influence tone decrease in importance as the signal path goes on, i.e.

MOST IMPORTANT > - - - - - - - > LEAST IMPORTANT
Player>Guitar>Amp>Cab>Room>Mic>Pre>Converter

 

[Metaltastic]

Yup

 

[MetalJonesy]

talking about the impedances, at the moment im using about 2kohm on my art pro MPA, do u rekon its worth knocking it down? i just find the top end then goes away and im not sure on an optimal setting, ideally im wanting to capture as much of the original freq spectrum as poss, but is it worth it for 57s for example?

like i said im on about 2kohm, and the difference between that and 3kohm is basically non existent, but say the difference between 3k and 800 is huge..

 

[lolzgreg]

I'm with Marcus on this one.

On recordingreview.com there is a shootout between a Vintech Dual 72, a Presonus M80 and a Presonus M80 with a shelf. Most people couldn't tell the difference at all for guitars. I don't think the difference is anything that you would notice in a mix, unless you are layering things, like Jeff said. I remember seeing an article with a math equation somewhere that explained why better preamps are imporant.

Paging JBroll...

 

[AudioGeekZine]

I just got a True Systems P-Solo last week. It's very clean and low noise. I also have a Profire 2626. With one of the P-Solo outputs going to an RME ADI-2 (spdif into the profire) and another going to a line in on the profire, there was almost no difference, they almost nulled, just some noise at about -50dB.
So that either makes the RME ADI-2 not worth the money as a higher-quality converter, or makes the Profire 2626 a very respectable one for the money. But as a way to get 2 more inputs into a system, it still has value.

Now the sound of the preamp, as I said the one I chose is known to be very clean with low noise, NOT a HUGE difference from the Profire 2626 ones, (actually comparing the Instrument inputs, not XLR), the P-Solo seemed to be more true. It was not a difference that was immediately apparent.
Adding the Universal Audio LA-610 instrument input DID make a noticeable improvement (for a clean direct guitar) the tube preamp makes an audible difference. You can quite easily hear a difference between the two impedance settings, with the highest setting (2.2M?) being nicest. With a different source it may not matter.


For clean preamps I recommend:
Grace or True Systems

For colored/more gritty preamps:
Universal Audio, Golden Age Project My friend loves his new Golden Age Pre 73, now I'm gassing for a couple of them.

 

[ahjteam]

I once tried to compare the SPL Track One (single channel preamp with lots of tweaking) with just gain adjustment and the cheapo 8 channel SM Pro Audio preamp. I recorded my unplugged hollow body guitar with Röde NT5 and split the signal using an Y-cable and tried to match the input level as near as I could, both went into RME Multiface:

http://www.ahjteam.com/upload/smproaudiopr8e_vs_spltrackone-01.wav

But I really have to say that the combojacks (XLR+TRS) are really badly built on the PR8E, because I have like broken four of the jack inputs in less than 2 years with just normal use.

 

[AllanD]

I only look for amount of headroom/clean gain in preamps nowadays. I realized there are so much more important things in the chain...