I'm writing my degree on the U47 and need your help

[Old Music Guy]

Part 2: Use case.
1. Vocals: Check
2. Piano: Check.
3. Jazz: Let's start with this one. As a drummer myself, there are certain and specific sounds that I want from every drum and every cymbal. Narrowing it down, I want a very crisp, very quick, very short response on my snare drum. I also want to hear each and every "ghost" note I play. I play them for a reason,. A U47 is fast enough (I'd love to know how much faster the FET pre is compared to the 12AX7 or 12AU7), has the dynamic range (according to the specs). Then there is the issue of "top/bottom" mic. The U47, or any condenser mic for that matter, is 180 degrees out of phase with a dynamic mic. Whereas a positive "pulse" on a dynamic mic result in a positive going slope at output signal. With a condenser mic, a positive "pulse" will result in a negative going slope at the output and a miniscule propagation delay. Thus, if you put a close mic'd U47 on the batter head, and a dynamic SM 57 on the resonant head for example, the engineer needs to keep phase in mind.
One other thing that needs definition in recording it the "sound/response" of the stick tip on a ride cymbal. This is often overlooked. A well placed U47 should perfectly capture that as it falls in the 5kHz to 8kHz range with little attenuation. This is an often overlooked nuance that should be easily captured with a U47.
Everything else speaks for itself, with reference to the "inherent" compression characteristics mentioned about.
4. Rock. I wouldn't put a U47 anywhere near a rock drum kit. It would be like driving your friend to the airport in a Lamborghini when a Cadillac would do. Save it for the vocal booth.

Conclusion: I would be hard pressed to tell the difference between a Neumann U47 and a clone. I would have a hard time differentiating a AT2020 and a Neumann. I know a condenser when I hear it, but given the signal path from the diaphragm to the tape, I think that, given the economics, I would opt for 5 clones for the price of 1 Neumann.

 

[rob aylestone]

You seem to have picked a difficult subject. Few available, no real history of what has been done to them over the years, a mic that ages, no real way of telling g what it sounded like when new, but also one that was always a niche product so a contemporary user base of dedicated users. I keep thinking how hard my modern U87 is to judge. I can measure it’s performance. I can take it places and record with it but educationally how would my supervisor sign it off other than as an option thesis? Will you have enough, at the same time and location to compare and contrast? Will the owners allow you to dismantle them and measure the components and determine how the sound is shaped! Can you remove one capsule and replace with another? All I can say is that if a student put forward this proposal for a BA here in the UK, let alone a BSc I’d counsel them out if it because the evidence collecting element is so subjective. Maybe this is ok in Germany? What title have you chosen?

 

[R D Smith]

@Old Music Guy thanks for having a look! The first poll is only regarding the expectations, the second poll will be with the audio blindtest. I'll be doing the recordings next tuesday, so hopefully I'll have it ready soon.

The reference will be a Schoeps MK4 small diaphragm condenser, not a mix per se. Tested will be

1. vintage U47 with M7 capsule and original VF14M tube
2. vintage U47 with K47 capsule and original VF14M tube (just confirmed today, so hooray for that!)
3. micparts V47 DIY kit with M7 capsule and 12AY7 tube
4. micparts V47 DIY kit with K47 capsule and 12AY7 tube
5. DIY Fet47 with K47 capsule matched to 4) and very similar head basket.
6. Townsend Sphere L22 modelling microphone with U47 emulation

Heres the link to the first poll: https://forms.gle/j7s5sinCDNKUBcjRA

I looked up the Micparts kits and they list a 6072a tube. Are the kits you have with the 12AY7 tubes older kits or a custom modification?

 

[Old Music Guy]

You seem to have picked a difficult subject.

Tru dat!
I've given you my opinion of a U47 based on published specs and use cases. Everyone's opinion will vary. That, in and of itself, poisons your data because it is subjective and not quantifiable.
Another thing I found is that the first question on your poll is, paraphrasing, have I ever used a U47? In my case, the answer is no. The poll is designed such that, if I don't answer the first question in the affirmative, I cannot continue. Thus, the only respondents to your poll would consist only of U47 users.
Moreover, the use of a poll would suggest some type of statistical analysis. Referring back to the poll, you've eliminated a sizeable sample size, which make the poll valueless.
I really would like to help, but, if it were me I would focus more on reliable measurements.
In the end, you will only skew your conclusion in your favor without the ability to back it up scientifically.

 

[md431]

You seem to have picked a difficult subject. Few available, no real history of what has been done to them over the years, a mic that ages, no real way of telling g what it sounded like when new, but also one that was always a niche product so a contemporary user base of dedicated users. I keep thinking how hard my modern U87 is to judge. I can measure it’s performance. I can take it places and record with it but educationally how would my supervisor sign it off other than as an option thesis? Will you have enough, at the same time and location to compare and contrast? Will the owners allow you to dismantle them and measure the components and determine how the sound is shaped! Can you remove one capsule and replace with another? All I can say is that if a student put forward this proposal for a BA here in the UK, let alone a BSc I’d counsel them out if it because the evidence collecting element is so subjective. Maybe this is ok in Germany? What title have you chosen?

Hi Rob, I agree that the only way I can attempt this is to record everything at the same time und the same take in the same room - which is what I'm doing. Everything else wouldn't hold up to a comparison. Getting in the details on how exactly these mics shape their sound would miss the topic of my thesis, which is the comparison of expectations vs. listening results. Besides that, the owners wouldn't be too happy about that. For at least one of the originals I have extensive documentation and history, as it's been in family ownership. My degree is a B.A. (can't chose here in Germany), so I'm focusing more on the psychological viewpoint rather than a technical one, though I'm doing some anechoic measurements to have some technical data to contrast.

Edit: It totally agree that if it were a BsC the focus should lie on getting more accurate data on how the circuitry affects the output and sound. In that case the polls as is would be fully unsuitable and opinions were irrelevant. That would be a different thesis though

 

[md431]

Tru dat!
I've given you my opinion of a U47 based on published specs and use cases. Everyone's opinion will vary. That, in and of itself, poisons your data because it is subjective and not quantifiable.
Another thing I found is that the first question on your poll is, paraphrasing, have I ever used a U47? In my case, the answer is no. The poll is designed such that, if I don't answer the first question in the affirmative, I cannot continue. Thus, the only respondents to your poll would consist only of U47 users.
Moreover, the use of a poll would suggest some type of statistical analysis. Referring back to the poll, you've eliminated a sizeable sample size, which make the poll valueless.
I really would like to help, but, if it were me I would focus more on reliable measurements.
In the end, you will only skew your conclusion in your favor without the ability to back it up scientifically.

Actually you get directed to a second, nearly identical part of the poll - so you can very much take part.
All I'm doing is separating the answers from "original" users vs. people who used replicas or none in case I want to do something with that distinction later. It's likely that I will mash the two data sets together to get a more general view.

Also I don't seek out objective answers by any means! I'm interested in the subjective viewpoint each person has and if there are any similarities and overlaps

 

[md431]

I looked up the Micparts kits and they list a 6072a tube. Are the kits you have with the 12AY7 tubes older kits or a custom modification?

Hey @R D Smith that's how they arrived, didn't order anything different besides matched capsules. Not sure if it's a supply thing

 

[Old Music Guy]

Also I don't seek out objective answers by any means! I'm interested in the subjective viewpoint each person has and if there are any similarities and overlaps

That seems like a more realistic, achievable goal.
If you haven't already read it, I would suggest a fabulous book by Daniel J. Levitin, "This Is Your Brain On Music - The Science of Music Obsession".
It may help give you some insight as to how humans perceive music, and my help you quantify some of the responses.
If nothing else, just look at his C.V.. It is not a long read, but very informative as well as entertaining.

 

[CoolCat]

I was reading about audiotestkitchen and they used a high resolution speaker and playback, with mic's then being able to have the same source.
I didn't finish reading all about it but it might have been in a anechoic chamber I don't know....

but having a playback to speaker and mic the speaker could work versus doing different takes or having a bunch of mics crammed into some space.

I'm curious in a lamens way what the circuit is and what each component is doing, always wondering if there's some "EQ" going on in the circuit.

U47 tube vs the U47 Fet was always interesting as even Neumann didn't get its goal, and the 47FET ended up a "kick drum" mic...although I think A CDC singer used it on vocals and whiskey sprayed capsule.

 

[CoolCat]

>The hero worship of things built in the past would lead you to believe that the human race forgot how to make a microphone in 1965 after the U-47,<clip

I saw some psych comment on how power of "stars" sell product, so it is what it is, in our DNA or something...some more than others...but the attraction of used by pro's who are successful blahblahblah

adding the unobtainable antique "art" collection then and someone with a bunch of money its a no brainier why prices go up. (which has nothing to do with sound really)

but its hard to filter the above out vs the actual performance of the product/invention/design U47 VF14 or whatever.

Also Recording Hacks did a small shootout with a U47 1953 and the MXL Revelation did well and the seGemini....
U 47 components varied, but all versions were transformer-coupled tube mics, and were quickly famous for their magical sound. The U47 didn’t attempt to reproduce a source, so much as improve it.
<clip>

 

[md431]

Hi all, quick update: I've done all recordings last week and am working on the processing of all data atm. Will message you soon when the blindtest is open, likely the day after christmas or so. Stay safe and have a good time!

PS: I call this new micing technique the "star of financial ruin"

 

[rob aylestone]

Somebody is bound to say it, but you cannot put a great pile of mics together like this because you are distorting the integrity of each one, by them no longer being in 'free space'. Remember how some classic 'special' mics got that sound from a normal capsule suspended differently, so sound took different paths. Think of the Neumann M50, on paper, an omni. Inside the omni capsule was mounted on a sphere, this created a 'preference' for sounds arriving from different directions. Your cluster of mics has done the opposite. Some paths to the capsules are blocked by others, or perhaps even reflected. As to hearing this, I don't know? Putting them this close, in an attempt to get them into the same space might colour the sound? Probably will? If we decide we cannot hear this, then we must also conclude we cannot hear other differences. You've taken it from an objective test to a subjective test, because we don't have any way of telling what the obstacles are actually doing?

 

[md431]

Its certainly a trade off and a tricky one at that. I chose relative position to sound source over colouration by the nearby chassis, as this gave me the closest result in the scenario I had. Ideally every microphone would have stood freely, and when I could because the relative position of the drums e.g. were further away (roughly 1,5m) so the few inches back and forth or left and right didn't matter as much as on a voice (40-50cm) for example, I did. In the other scenarios I tried to keep the "constraints" by the other mics as similar as possible, for example on having a responsive surface towars the top or side of the grille.

But as all recordings are essentially a bunch of compromises, so is this one. It's not ideal, but close enough for my purposes. I could have done a second take in the sessions with all mics but one removed, but then I'd have differente performances and slightly varying positions again, which makes comparisons tougher. So yeah, it's a trade off.

 

[md431]

In hindsight, I propably should've got someone to knit tiny christmas sweaters for all of them to minimise reflection

 

[TalismanRich]

I've seen comparisons where they had 4 mics in a star configuration from some of the bigger houses (Might have been Vintage King or Sweetwater). While it might have some effect on the sound due to interaction, I thought it was better than the alternative, which has usually been having someone sing or play the same thing with each mic. Unless you're Freddy Mercury or Karen Carpenter, that's a really tall task. There are ALWAYS subtle variations in the performance at best, sometime there are gross variations.

One of the best comparisons that I've seen involved a Yamaha Disklavier grand piano. That way the performance was as identical possible, so they could carefully place the microphones, leave the room and let the computer play the piano. It was probably very time consuming, but you did end up with recordings of real performances of a real instrument.

 

[CoolCat]

I think the big Sweetwater shootout was "free standing" mic on stand and the singer moved from one Mic to another doing many performances.
Neumann anechoic has a speaker and the mic faces the speaker allowing repeatability of the source and they can compare to specs for calibration work.
Watching a SHURE video with the anechoic chamber and also a sound source/ speaker with the mic on a motorized gear wheel that could spin the microphone showing the Pattern of the capsule sensitivity etc..
Many tests use the "cluster" 4 star" mic and one performance - in a room.
The U47 could be tested by having the 47 Free Standing vs 4 Star to see if there's a huge difference.
But for a test you go for it and compare and put the details of the room etc in the footnotes. right?

I've done a bunch of comparisons in my closet sized mic room studio and in the other rooms here. There might be some differences of rooms but in voice and 6inches and all that I could get an idea of the sound or sensitivity or patterns. I wasn't passionate enough to build an anechoic chamber BUT! a small mic box could become a possibility or to use a Speaker as a source instead of varied performances. At some point the engineer brain and the artist brain collide and even the Neuman and Shure and Engineers settle on 1 graph per pattern versus 5000 graphs each with the mic titled /025inch each measurement..lol I work in Research and for decades of testing devices and calibration of tools is what we do, while some professors are kind of the "artists" making some new thing. repeatability is important. specs all have some tolerances. +/- .

The other world is the dudes in the studio making "art" where they plug the mic into eqs and compressors and tubes or transformers or clean chip devices and maybe doubling- or delays on purpose where the "art" approach is painstaking effort in capturing some sound to create a vibe or something aka Im The Walrus was recorded with a talk-balk mic to get a dirty, distorted vocal sound vs maybe a clean U67 on Hey Jude or something.

I read somewhere, was it a Neumann old ad? the U47 was made to "improve" the sound which is a little "art" as its not designed to be a flat measurement mic at all.
wow..so many designers trying to clone the U47 too. probably some psychology going on in the Marketing meetings! lol

 

[md431]

Re the part of overthinking the measurements - absolutely. I did 5° increments of rotating on an motorised podestal specifically designed for this until I settled on 8° increments, which mean a lot less work for me in post for varying reasons. Even 10° increments propably would have been more than fine.

In the chamber itself each microphone was standing on its own with nothing in the room exept the speaker. I've attached a picture from a testrun for reference, unfortunately the only one I thought of taking has my stupid face in the way. I did want to use the larger Neumann KH140, but the damn things were locked down in our studios since beeing set up as atmos setup and I was sternly reminded I'd be dead meat if I moved them as much as an inch lol

As the wire-mesh flooring was a little wobbly, I did put everything on a flat board but covered it in non-reflective material to minimise reflections. Though funnily I did receive an uncharateristic 3dB peak at 107 Hz in all measurements which I just realised I could probaply attribute to this, given the speaker was 1,5m away and the mic about 1,5m above the board, resulting in roughly 3m travel distance. Might be my just-woken up brain scrambling for reason though

 

[CoolCat]

pictures are cheap ...snap a bunch of them! especially the mics and room.
enjoy the thread and drilling down.

 

[md431]

Hey all, here it is: https://www.soscisurvey.de/mythosU47/

This is the blind test including all vintage U47s and a few others. Please use an adequate listening situation, e.g. studio speakers or good headphones, as the differences can be subtle. It should take about 15 minutes.

Important: Please don't post spoilers that might influence others experience! This would alter the results in a way I really can't factor out.
If you like we could open a discussion thread though


Massive thank you to anyone who took the time! You really help me out a lot.

 

[Papanate]

Hey all, here it is: https://www.soscisurvey.de/mythosU47/

This is the blind test including all vintage U47s and a few others. Please use an adequate listening situation, e.g. studio speakers or good headphones, as the differences can be subtle. It should take about 15 minutes.

Important: Please don't post spoilers that might influence others experience! This would alter the results in a way I really can't factor out.
If you like we could open a discussion thread though

If you used the mics in question - it is realtively easy to hear the differences.