PlanetZ forums - scopeusers.com

Not sure if there's been a thread about this on PlanetZ before, but it's been heavily discussed elsewhere. I thought I had seen it mentioned here, but couldn't find it again. Anyway, it's quite interesting & I was going to post it in the mic pre thread by Korgano, but realized that this probably needed it's own thread. Rather than summarize the whole thing I'll just say that it's about a little (non-scientific) test between 3 mic preamps, one costing well over $1500, one @ $200 & one costing less than $5 that was conducted by an Audio Masterclass tutor in 2006 who said 'One thing's for sure. The cat's among the pigeons and feathers are flying'. There's audio files for 2 different mics running through each of the 3 preamps, so 6 audio files in total that let you compare the 3 mics pres. Listen to the 6 files (A1-3 & B1-3) before going to see the results of the class poll.

Microphone preamplifiers - can *YOU* hear the difference? (with audio) - (the test)

Well, could *you* hear the difference? Could you?? - (the results)

Let me know what you think & if I'm repeating something that's already been discussed here on PlanetZ, please feel free to point to where that was.

cheers,
Mark

EDIT - I should add that this particular test is VERY specific & only related to the 2 mics & 3 preamps used. It's not a generalization that can be applied to just ANY mic & mic preamp comparison.

HAHAHAHA
thats great.
DIY wins again

its a bit unfair using battery power against any mains power though. the power supply accounts for a large part of the price on the high end tube amps. and you would need a big battery to keep them glowing

someone has to do the other test though. once you tell some people the price of the equipment their brain makes it sound better. thats how you sell speaker cables for $24000

im off to texas instruments website to get some free INA217 samples
i have the rest of the stuff "in stock"

without having a look at the 'Test'...
one thing for sure: I once bought a Midiman Audiobuddy based on files of a big Mic-Pre-Shootout in a German mag. Hires .wav files on CD and I had all the time in the world to listen.
I probably don't have to mention the box is crap, as you guessed it anyway...
yet the files did sound very good indeed

cheers, Tom

Neutron wrote:its a bit unfair using battery power against any mains power though.

Yeah, the article writer mentions that's likely the reason for the result. It's also a bit crazy to use battery power for a mic pre anyway unless you want something ultra portable, but there's plenty good options on the portable recording front these days that wouldn't cost you an arm & a leg for the battery power like this one would with it's 9 x 9v batteries.

Neutron wrote:the power supply accounts for a large part of the price on the high end tube amps.

Well, that's the thing. Good power supplies aren't cheap to buy anyway, never mind one that's custom built.

astroman wrote:without having a look at the 'Test'...

It doesn't really say that much anyway TBH other than 'look what you can do with some electronics skills & equipment, a few bucks, a circuit diagram from a data sheet & some time'

Btw Neutron, I think when the test was originally posted on audiomasterclass.com, the identity of the 3 preamps was kept secret until the poll ended.

Tom, the 'Test' was also a bit screwed anyway, since they used a fixed max gain for the amp IC instead of variable & after later adding the phantom power realised that the 50dB or whatever they had it set to was too much for the U87 mic, so the guy had to stand at a greater distance with the U87 which introduced more room ambiance. Shame they didn't think to just swap out the resistor setting the max gain.

Shroomz~> wrote:

astroman wrote:without having a look at the 'Test'...

It doesn't really say that much anyway TBH other than 'look what you can do with some electronics skills & equipment, a few bucks, a circuit diagram from a data sheet & some time'

Btw Neutron, I think when the test was originally posted on audiomasterclass.com, the identity of the 3 preamps was kept secret until the poll ended.

I know that, im just saying they should do a different test where they do tell people the price, and see if the results are different. (and use exactly the same wav for all of them)

It has always been a bit difficult for me to tell a huge difference with a singel signal put through 2 mic preamps.. but once i start layering a lot of tracks there is a GREAT difference in sound quality.
I have been tracking a whole song with a 8 chnl. cheap mix preamp box, and the whole thing ended up sounding unfocused and... well just not good! i had to tweak ALOT before i got a decent result!
i then got my hands on an old revox c279 mixer. ( same insides as some studer mixers) and then tracked another song through that. there was great difference, and i dont really have to tweak anything!

So my conclusion is that i cant tell a great difference on single tracks, but a whole song!
that said, i am sure there are alot of very good sounding cheaper mic pres out there...you just have to know which ones

the19thbear, well said.

Yep, they should definitely have at least done this test with a variety of wider bandwidth sources as well, like some acoustic instruments to get a better idea of the results.

the19thbear, are you talking about the difference you found between mixing multiple tracks digitally that were going through an 8-ch mic pre then direct into a DAW in comparison to actually mixing them to a stereo bus (or several group buses) on an analogue console? It seems to me that there's always going to be in immediate & noticeable difference between the 2 since the analogue mix bus & groups are going to enforce a unique dynamic character to the mixed material before it gets anywhere near your DAW. Is this what you mean?

Neutron, sorry mate, misunderstood you. ... btw, I hope you post some reports & results if you build a preamp with that INA217. .. check out the 'LAB' forum on this site if you haven't already. There's also some people on gearslutz that have been building preamps based on the data sheet for that INA217 chip.

yeah, I really should get my hands on one of those opamps, too - just to be sure.
I found so much more 'definition' and detail in my all-discrete preamp that I hardly trust any ICs at all anymore. And I just love Trrraaaaaansformaz

cheers, Tom

Btw, the DAV BG1 (amongst other preamps) apparently uses that INA217 IC !!!

i was talking about recording different signals into 8 cnhl crappy preamps...

I just meant are you summing channels on the revox mixer?

nope.. summing digitally i have been thinking about summing analog though.. just need to buy all the cables

Shroomz~> wrote:
Microphone preamplifiers - can *YOU* hear the difference? (with audio) - (the test)

i didn't went for result yet but i like:
A2 is 1st than A3 than A2. ok now lets see the results.

Shroomz~> wrote:Btw, the DAV BG1 (amongst other preamps) apparently uses that INA217 IC !!!

maybe they put in some of Jack Bybee's Quantum Purifiers to make it even better
http://www.bybeetech.com/ourtech.asp
still highly classified of course, since its just a 0 ohm resistor.

firubbi wrote:i didn't went for result yet but i like:
A2 is 1st than A3 than A2. ok now lets see the results.

It's no real shock that you liked mic A, which was the Shure SM57 firubbi, since it was apparently better suited to the max gain set for the amp IC in that little circuit. Quote from the article:- "To make the circuit simpler to construct, a fixed gain of 50 dB was set. This proved to be too much for the U87, which has a higher output than the SM57 and clipped the audio interface, so I stood a little further away. This accounts for the increase in room ambience, and for the lower LF content because of the reduced proximity effect. I could have clicked in the pad on the mic, but in the moment I chose not to."

Neutron wrote:

Shroomz~> wrote:Btw, the DAV BG1 (amongst other preamps) apparently uses that INA217 IC !!!

maybe they put in some of Jack Bybee's Quantum Purifiers to make it even better
http://www.bybeetech.com/ourtech.asp
still highly classified of course, since its just a 0 ohm resistor.

0.025 ohm. ...Anyway, I doubt that DAV used those things or the price of their preamps would have to be at least $500 more.

Shroomz~> wrote:

firubbi wrote:i didn't went for result yet but i like:
A2 is 1st than A3 than A2. ok now lets see the results.

It's no real shock that you liked mic A, which was the Shure SM57 firubbi, since it was apparently better suited to the max gain set for the amp IC in that little circuit. Quote from the article:- "To make the circuit simpler to construct, a fixed gain of 50 dB was set. This proved to be too much for the U87, which has a higher output than the SM57 and clipped the audio interface, so I stood a little further away. This accounts for the increase in room ambience, and for the lower LF content because of the reduced proximity effect. I could have clicked in the pad on the mic, but in the moment I chose not to."

garbage test.