Hello,

In October's issue of Sound On Sound we tried to cut through some of the hype surrounding mic preamps, to find out how much of a difference they really made in one particular real-world recording situation: tracking a grand piano. Jonathan Dodd of Realpiano was kind enough to let us use his Yamaha Disklavier, which can reproduce the same performance from a MIDI file with uncanny accuracy. Session pianist Matt Cooper created a short MIDI piece that gave the piano a full workout, and we recorded it... over and over again!

We used three different mic setups: a pair of Brauner cardioid valve mics, a pair of Sennheiser MKH20 omni small-diaphragm capacitor mics, and a Royer SF12 passive stereo ribbon mic. These were recorded in turn through eight different preamps, representing a wide range of design approaches, from the preamps in a budget mixer to a valve preamp costing over £2000. Subscribers can read the full article here, and the audio files are available for everyone to download here. The catch is that I've removed any reference to which preamp is which from the names of the files...

...so, how much of a difference can you discern between the preamps, and can you guess which preamp is which? The key will be revealed in due course, but as a quick reminder, the eight preamps featured were:

AMS Neve 1073LB
API 3124+
ART Pro MPA II
GP Electronics PML 200E
Mackie 1402 VLZ Pro MkII
Maselec MMA-4XR
Prism Sound Orpheus
SSL XLogic VHD Pre

These are referred to (not in the above order) by the letters A to H in the audio examples.

We're very curious to hear SOS readers' opinions!

I'm quite curious to find out which is which, I could do with a second preamp and I hope that
I prefer one of the cheaper preamps.

However the more I listen to them the more confusing it gets so I've just listened to the
first section to keep it simple.

Favourite
(A) Smooth 'tubey' top end.
(H) Sounds more stereo than others?
(E) Clean accurate, neutral and smooth.
(D) Good not much character. is this cheap?
(B) Classy vintage sound. is this expensive?
(G) Clean accurate neutral
(C) Vague/dreamy mids
(F) Dark
To Least Favourite

Listening to the next microphone section somewhat changes the ratings,
so I guess I'm just rating the combination of Brauner and pre.

Edited by tiberius (21/09/12 01:46 AM)

Having only listened to the SF12 variations so far. To be perfectly honest, this kind of makes me want to send back my semi-expensive preamps to the dealer... The differences between these preamps are -from what I can hear, totally negligible for the type of (pop) productions I am involved with.

Maybe a little difference does add up once you start piling tracks on top of each other, but unless someone convinces me otherwise, I'm inclined to think I'd be just as good off with my standard interface preamps for that floor tom at the back of the mix.

When I started recording, just about everyone used the preamps in the desk and just got on with it. A few people, mainly American, talked about using different preamps but most engineers didn't think that the small difference between properly designed preamps was worth the effort. Mic choice and positioning is still far more important than preamp choice but I guess the marketing people have taken over now and confused everyone.

James.

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JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.net

Interesting, I'll have a listen later, not that I really use pre-amps in my music, but it will be interesting nonetheless.

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http://soundcloud.com/richie-royale
http://www.mixcrate.com/richieroyale

It was a very interesting test to do -- and finding the Disklavier was the key to making this work as we could think of no other way of ensureing reliably repeatable performances for each mic/preamp combination.

When we were listening back to the recordings -- in full knowledge of what preamp was in use -- we were convinced we could percieve significant differences. But when the recordings are anonimised it is actually remarkably difficult to accurately identify each preamp!

We specifically chose to challenge the preamps with low output ribbons and high output capacitor mics, and to use a wide dynamic range source... but we didn't try deliberately 'pushing' the preamps to force preamp character that way -- these were all essentially purist recordings and, as you can plainly hear, even the cheapest modern preamps manage to deliver a perfectly usable sound that is pretty accurate and uncoloured.

James is quite right when he says mic choice and positioning are far more critical in terms of sound quality and character... although I think the better preamps still do manage to capture or deliver something that is subtly preferable given a choice.

H

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Technical Editor, Sound On Sound

Fascinating one this! Like Hugh I felt that all the preamps put in a usable performance -- certainly from a mixability perspective within a normal commercial production context.

That said, I probably wouldn't choose preamps F (slightly 'plasticky' somehow), C (felt a touch boxy tonally), and B (too strident in the midrange) based on these files, and my opinion was that A, D, and E gave the clearest presentation across all the mics. G and H were also alright, but the former rather muffled at the high end, while the latter seemed to be the opposite in that it seemed a little zingy. To use the most scientific of terms...

But I'm almost positive I couldn't reliably tell which one I was listening to in a blind test.

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Mixing Secrets for the Small Studio
A complete mixing method based around the techniques of the world's most famous producers.

This is a fascinating test, particularly since I'm currently evaluating a range of Nebula 3 character preamp presets for a forthcoming SOS review that include an API and ART tube models. It also echos my views (already mentioned by Frank) that mic, mic placement and acoustic treatment choices are all mroe important that any tonal difference between preamps.

Thanks for putting in all the effort guys, although I suspect a few people may consider that 96kHz files might demonstrate any tonal differences more clearly!

OK – on a fairly brief listen I'll throw in my two pennorth.

Quote Sam Inglis:

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I forgot to mention one thing... The letters are NOT the same for each set of mics. In other words preamp A for the Brauners is not the same as preamp A for the Sennheisers or Royers. Apologies for the confusion - I thought it would be best to change the order each time as that can have quite an influence on one's perceptions.

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DOH!!

Here are my original notes for all three separately then

Brauner

A nuetral and rich - NICE!
B slighty veiled at top end, otherwise rich mids and low end
C slightly harsh midrange
D bigger bottom end NICE!
E clearer, more transparent NICE!
F close & intimate
G slightly distant
H closed in


MKH

A no particular sound
B intimate, can hear further in NICE!
C slightly hard midrange
D nuetral
E intimate
F warm, close and detailed
G warm and intimate
H rich mids



Royer

A less detailed
B shrill top notes
C warmer bottom end
D delicate, intimate
E less detailed
F detailed yet nuetral, with midrange richness - NICE!
G less detailed
H shrill & slightly harsh

Your mileage may vary



Martin

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YewTreeMagic

Hi,

Nice test !

The first thing I could say is that differences are really really subtle ...

But I'll go for the E !

Edited by DVallet (21/09/12 04:40 PM)

H is the most obviously different over all the mics. I've only had a quick listen but it stands out against the others; something veiled or murky about it makes the low end a bit more prominent.

What is the piston like noise? Is it the mechanism playing the keys?

The most obvious thing is the difference between the mics, which sound quite different, but both nice. I think the Royer would be mice choice, but I've not listened properly yet.

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http://soundcloud.com/richie-royale
http://www.mixcrate.com/richieroyale

I need to listen properly to work out an order of preference but they only one that made me sit up was E. Great clarity.

I noticed the loudest part of the track clips briefly....was this intentional so we could hear the preamps pushed to their limit?!

I forgot to mention one thing... The letters are NOT the same for each set of mics. In other words preamp A for the Brauners is not the same as preamp A for the Sennheisers or Royers. Apologies for the confusion - I thought it would be best to change the order each time as that can have quite an influence on one's perceptions.

Quote Sam Inglis:

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I forgot to mention one thing... The letters are NOT the same for each set of mics. In other words preamp A for the Brauners is not the same as preamp A for the Sennheisers or Royers. Apologies for the confusion - I thought it would be best to change the order each time as that can have quite an influence on one's perceptions.

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Ha, good idea. In which case, I meant that E in the MKH20 lineup stood out for me!

Quote mjfe2:

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I noticed the loudest part of the track clips briefly....was this intentional so we could hear the preamps pushed to their limit?!

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No! It was a boo-boo. I thought we were recording a bit hot, but at the time we didn't spot it on playback so I let it go. There's also a problem with the Brauner H file which has just been pointed out to me. I'll fix that on Monday.

interesting article. Preamp examples are pretty hard to pick apart from each other. I tended to prefer D, E and H and only really had an issue with C which sounded a little thin to me. On another type of source (horn etc)... I might prefer A which sounded especially roasty. (For the Brauner comparison)

Edited by gennaroschiano (22/09/12 05:47 AM)

Quote Sam Inglis:

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I forgot to mention one thing... The letters are NOT the same for each set of mics.

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I'd assumed they were -- I'll have to have another listen! My comments above were mostly based on the Brauners, though. Still, the fact that I didn't notice illustrates how little I can reliably identify which preamp is which!



--------------------
Mixing Secrets for the Small Studio
A complete mixing method based around the techniques of the world's most famous producers.

Ah that explains a lot. I thought I'd need a different preamp for each microphone...

Hmmm... I think the point is already proven: while there are subtle differences between preamps, they really are very, very, very subtle and not terribly significant in the grand scheme of things for most situations. If you like to push the preamp for deliberate colouration, of need unusually high gain for distant ribbons the differences might become more important. But in general, modern preamps are all remarkably good -- even many cheap ones!

H

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Technical Editor, Sound On Sound

Quote mjfe2:

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I noticed the loudest part of the track clips briefly....was this intentional so we could hear the preamps pushed to their limit?!

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No, not intentional at all -- it was an annoying faux pas. Our host was 'old school' and liked to work with negligible headroom... And was caught out on occasion. The large number of permutations we had to work through and the limited time meant we weren't able to audition all the playbacks and repeat takes. Profuse apologies -- but I don't think it detracts too much from the aim of the comparisons.

H

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Technical Editor, Sound On Sound

Quote Hugh Robjohns:

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Quote mjfe2:

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I noticed the loudest part of the track clips briefly....was this intentional so we could hear the preamps pushed to their limit?!

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No, not intentional at all -- it was an annoying faux pas. Our host was 'old school' and liked to work with negligible headroom... And was caught out on occasion. The large number of permutations we had to work through and the limited time meant we weren't able to audition all the playbacks and repeat takes. Profuse apologies -- but I don't think it detracts too much from the aim of the comparisons.

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No worries, it hasn't detracted from what is a great comparison. As for 'old school', if only people appreciated that old school is really leaving 20dB or so of headroom! If only everyone read this: http://www.soundonsound.com/sos/sep10/articles/qa0910-1.htm

Not really an unexpected result, as you say, anything reasonable is usually not going to be the weak link.
Preamp choice is as much about studio marketing as sound engineering, the client wants a U87 with an Avalon preamp, fine, that is what hire is for, will it make a difference, probably not on a technical level, but if they are happy, odds are I will get a better take.

I do notice however that the SF12 is the only mic in the test that lacks an active output stage, all the others have the impedance converter in the mic (which is effectively the first stage of the preamp), it might be that throwing an SM57 or RE20 or something in there would have been rather more revealing of any differences that were there?

Given that for me this test is as close to a null result as makes no difference, I am just wondering if some of the claimed 'major' differences between preamps might be down to preamp/mic interaction, which will surely be reduced substantially by using mics with built in power gain.
Some of it is clearly differences in clipping behaviour, and most of it is probably marketing bulshytt aided by a healthy dose of nobody calling the emperor out for public nudity, but I just thought I would flag up the (quite reasonable) limitation of the study.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

Yes, it does seem as if you avoided testing microphones that MIGHT have responded differently with different preamps. Whether it would take anything more than a suitable shunt resistor to level the field is another question!

Yea, going there is a combinatorial explosion however, and it is not even clear that there is a meaningful effect there to be found.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

this is a lovely example of the craft - the craft of capturing audio properly. Mics and mic placement - rooms are gifts or curses. Good ears know the difference. Some of us have 'it' some of us dont.

For me the best preamp is A.
Warm, clean and detailed.
But I listened only on headphones, when I'll have enough time I'll try listening on my speakers.
Very useful test.
Thank you SOS!

Quote Exalted Wombat:

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Yes, it does seem as if you avoided testing microphones that MIGHT have responded differently with different preamps.

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Not at all, that was exactly why we included the Royer ribbon mic. In theory, a passive ribbon mic with a transformer balanced output should be sensitive to the preamp's input impedance, and also of course requires a lot more gain than most capacitor mics.

We did think briefly about trying a pair of SM57s or similar. But then we thought 'Who the hell records a grand piano with a pair of 57s?'

I have seen it claimed repeatedly on other forums that preamp choice makes a massive difference even with modern, high output capacitor mics...

Quote Gianluca5080:

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For me the best preamp is A.

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Again let me reiterate that A is different in each set of files - the order is not the same.

Apologies if I've missed it but... are the actual results anywhere? I bought the magazine and I cannot find the actual results. They are not on here either. It's only fair to actually put the results somewhere and let people choose to know or not know whilst they listen to the results.

Yes... they're in a text file on my computer at home!

We will be making the key available later on, but for the time being, it's a blind test for everyone.

Fair enough - could you blummin' hurry up then! Will it be today? Just put a link up that people can either choose to click on or not, should they want to know.

Regarding Preamps in general, there is certainly an obsession, especially in the U.S where I've known people refuse to record until their chain is in place... the correct mic is not enough. Neve or Neve-alike pre's usually get the nod for vocals with API for recording drums or bass. Neve alike pre's can be an attractive option with the Aurora being a favourite and the Great River pre's being a nice neve'ish option.

I can say from personal experience, mics can sound a lot different through different pre's and I think people do underestimate the link. For instance, I have a Peluso VTB and for vocals, through an API pre, it sounds brilliant, same through an Apogee (Mini-Me) - however through a UA 610, it does not sound right at all. I want to trial a Neve with this mic. On the flipside, other mics sounds right through the 610. The 610 seems to impart a darkness to the signal and can be nice hooked up to a brighter mic with less bottom.

Anyway, I'd like to see a similar test done to the one here but with different sources - as some will shine in one area whilst others will shine elsewhere. Ideally, a test with these pre's but with vocals, drums, etc etc; would have been brilliant.

Thanks RW. I guess it would be easy enough to do a similar test for electric guitars, thanks to the wonders of re-amping, but with sources such as drums and vocals, you run into the problem of how to ensure a precisely repeatable performance.

Quote Sam Inglis:

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Thanks RW. I guess it would be easy enough to do a similar test for electric guitars, thanks to the wonders of re-amping, but with sources such as drums and vocals, you run into the problem of how to ensure a precisely repeatable performance.

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I agree but I think people would forgive you for not being able to accomplish the exact same take - it might still show some of the characteristics of different pre's. Maybe one for a future issue... the 'pre-rematch'!

RW has nailed it for me.

Good as this comparison is, I don't think it addresses the real reason why I think people want different pre-amps which is - what Pre-amp/mic combo is more likely to suit the source.

Its widely agreed that you should select an appropriate mic for the source/room, so why not a pre-amp? It may make a smaller difference but if it makes even a small one its worth it. Anyone who has purchased any high end piece of audio gear is aware of the law of diminishing returns, but we do it as any improvement however small is usually worth it.

As has been stated, If you do rock guitars and have either ribbon or dynamic mics, you are going to find an API style pre-amp does the business more often then not due to its fat mid push, and tight low end

Acoustic guitar recorded through some SDC's? Neve style pre-amp is probably going to do it for you, as its general character has a sweet top end and big bottom.
Thin/harsh or 'reedy' vocal through an LDC - Neve again is probably a good place to start for similar reasons as above.

It doesn't work in every case and you should always try a few pre's/mic on things you are unfamiliar with, but as a general default it works, and at the very least provides a good starting point or frame of reference...

I quite agree that the mic / preamp interface can be a major source of audible differences with passive mics, and that's why we included the Royer mic in the test. Even so, differences are still often very subtle and mic positioning is still the dominant factor.

Hugh

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Technical Editor, Sound On Sound

Quote jaminem:

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I don't think it addresses the real reason why I think people want different pre-amps which is - what Pre-amp/mic combo is more likely to suit the source.

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Surely that's precisely what this comparison questions? The mic positioning is clearly critical, and the sound of the mic is significant in the overall tonality, but does the mic pre really make that much difference, or is it actually largely wishful thinking? It became fashionable to pair mics, pres, and sources, to the extent that it has entered urban mythology and become 'widely agreed'... But how much validity underlies that?

Yes, transformers and valves can impart audible character that can be help or hinder depending on the situation, but I would suggest its never a deal breaker, and the desired character can usually be obtained through different mic choice or placement. That's the way I was trained, anyway, because the only pres were those in the console -- and that's the way thousands of hit records were made!

It's always worth questioning 'widely agreed' things from time to time...

Hugh

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Technical Editor, Sound On Sound

Quote Hugh Robjohns:

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Quote jaminem:

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I don't think it addresses the real reason why I think people want different pre-amps which is - what Pre-amp/mic combo is more likely to suit the source.

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Surely that's precisely what this comparison questions? The mic positioning is clearly critical, and the sound of the mic is significant in the overall tonality, but does the mic pre really make that much difference, or is it actually largely wishful thinking? It became fashionable to pair mics, pres, and sources, to the extent that it has entered urban mythology and become 'widely agreed'... But how much validity underlies that?

Yes, transformers and valves can impart audible character that can be help or hinder depending on the situation, but I would suggest its never a deal breaker, and the desired character can usually be obtained through different mic choice or placement. That's the way I was trained, anyway, because the only pres were those in the console -- and that's the way thousands of hit records were made!

It's always worth questioning 'widely agreed' things from time to time...

Hugh

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I agree for the most part and for sure, mic and position is the biggest deal but I can honestly say that different mics can work and interact differently when paired with different pre's and in my experience, the difference can be quite big; I'm talking mainly on vox, in my case. Of course, there's then the whole other argument about driving a pre - such as an API for more saturation VS keeping it clean.

In any case, it's a great test you've done and it's good to see the pre' myth being questioned / tested and brought to the fore.

Quote R W:

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I can say from personal experience, mics can sound a lot different through different pre's and I think people do underestimate the link.

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OK. Do you agree, however, that this test indicates that mics DON'T sound a lot different through different preamps?

It's most heartening that a gear-based magazine should have published a comparative test of master clocks ending with "but you probably don't need one" and now a blind test of preamps demonstrating (would you agree?) quite conclusively that they make little if any audible difference.

Cheekily withholding the information that A in the first test wasn't necessarily A in the second should have made a few people (a) feel slightly embarassed then (b) think pretty hard!

Performance first, then Instrument, Mic positioning, Room, then a long way behind the details of the rest of the chain.

The obsessing over really tiny details I mostly do not really get, I mean even the cheapest prosumer preamp and ADC are orders of magnitude better then the stuff they used to capture Muddy Waters, Miles Davis, Ella Fitzgerald and the Beatles....
What is usually not better is the room, the performances and the skills of the operators.

Sure it can be interesting to measure and experiment with the small stuff, but it is very much the case that it is mostly interesting to recording types rather then being something likely to make a major impact on the shipping product volumes.

Preamps are largely a marketing thing at every level of the trade, from manufactures marketing four colour glossies, down to studios selling on having the shiny kit (Why do you think the Avalon stuff has that massively machined front panel?).

One interesting thing to do is to take a high end condenser and two speakers and do some IMD tests on the thing, it usually fairly quickly becomes apparent why condensers have a reputation for a slightly sizzly top end (Hint, it is mostly non harmonic mixing products due to the mics non linearity, which is why it does not show up on a single tone sweep), against a glaring issue like that, the details of what the preamp does are largely irrelevant.

About the only piece of the recording chain that is not so close to perfect as makes little difference (even with cheapish, but not bottom feeder kit) is the transducers at either end, and the room they are in, everything else is noise in comparison.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

Quote Exalted Wombat:

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Quote R W:

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I can say from personal experience, mics can sound a lot different through different pre's and I think people do underestimate the link.

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OK. Do you agree, however, that this test indicates that mics DON'T sound a lot different through different preamps?

It's most heartening that a gear-based magazine should have published a comparative test of master clocks ending with "but you probably don't need one" and now a blind test of preamps demonstrating (would you agree?) quite conclusively that they make little if any audible difference.

Cheekily withholding the information that A in the first test wasn't necessarily A in the second should have made a few people (a) feel slightly embarassed then (b) think pretty hard!

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Well, I think the test they've done is good - I'm just saying that from personal experience, I have some nice mics and pre's to hand and, on vocals, I can hear quite a large difference. To the extent that, I would now never pair my VTB with my UA pre. Whilst I may pair another mic with it. I completely agree that the performer, mic and room are more important than the pre, no doubt about it. That doesn't mean that it's not worth exploring these things. One thing to note is that any tiny difference becomes magnified when you stack tracks... so for vocals, for instance, if you stack a ton of tracks, the character of the pre can become very evident. Neve pre's seem to have a pleasant harmonic top end that may seem almost inaudible in some cases - but it is there and if you have a ton of tracks recorded though a Neve, that pleasant 'feature' does add up.

So what is the legend? Which pre amp correponds to A? to B? etc? Have I missed something here
?