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[maarvold]

Quote:

There is not a single first call L.A. scoring engineer who does not have a palette of transformer -coupled spot SD condensers in his arsenal

Klaus, this is not accurate.  Dan Wallin uses TLM170s, Sennheiser MKH40/80/800, TLM50 and SM69 (not a small diaphragm).  Armin Steiner uses primarily MKH40/80/800.  Some examples of their work are "Seabiscuit", "Finding Nemo", "Far From Heaven", "The Road To Perdition" and (Pixar's soon to be released) "The Incredibles".  Ironic, since these two represent the 'old guard' of orchestral scoring mixers here in L.A., yet both embrace the modern transformerless designs.    
Dan--who has been an audio professional since before the L.P.--thinks transformerless was one of the best things to ever happen to microphones.  And he thinks of TLM170s as a modernized version of the U-67, a mic I have also seen him use, and use quite happily, when there were no TLMs available.  
Maybe there should be a new topic: When using first class electronics, what less destructively conveys the sound of the source: transformers or transformerless?  

[David Satz]

Klaus, I would like to hear more about your signal injection test--it seems like a very useful experiment. Could you say which fet 80 microphone this was?  Large vs. small transformer size would be a crucial bit of information.

Also, did you try anything other than a midrange-frequency test signal, especially anything near the bottom of the range (20 - 30 Hz)?  A transformer that's being saturated by low-frequency signals can't pass midrange tone even if the midrange headroom (measured separately) is very high.

[Oliver Archut]

Hello David,

I do not argue that those Bayer inline x-former where pieces of S**t, I do not argue about that there is no good SD x-former used since the KM5x and the Hiller pencil mics (the large x-former was sitting in the PSU). But the statement that only TLM circuit can handle the High SPL and Bandwidth is were I do not agree.

Sure a x-former has physical limitation the smaller you get the harder is it to get a good transmission, if you want the luxury of miniature mics, go without a x-former, but something is missing. What exactly is missing is the open question, I never heard a TLM mic that has the character nor the resolution than x-former coupled mic.

I do not argue about the limit of the SPL in historic mics, but than again all great recordings I admire and respect where done before the  age of TLM mics. All great movie scorings, my all time favorite records either Popular or Classic and Marching music.
Maybe it is the approach of getting to a recording, with all this great technology there is nothing that grapped my attention in the last 20 years.

The SPL of most good working U47 is about 115 to 120 dB, than again this number can be easy bumped up, by changing the plate and cathode resistor while increasing the B+ voltage, the x-former still works fine before the capsule reaches 5% THD. The end result is that the sounds suffers.

I see there is a major differences in live recording or creating sound in a studio were size doesn't matter; there is no live recording that comes close to the real thing, and if you try to hide your mics because the audience might be annoyed, that is the wrong reason to use mini mics.

To bring it to a point, every circuit is a compromise bound by several limitation factors, you always trade one advantage with a shortcoming. A transformerless has the advantage in small size mics, but size is trade of with sound.

I do not think there will be a resolution why it sound, how it sounds, etc. But a good topic to think about.

Best regards,

Oliver

The Hiller M59 is one of the best SD mics, holds up with SPL and bandwith of any TLM mic but the mic is nearly as small as a modern SD. Only made from 1946 to 1949.

[natpub]

Hey, I am a composer. This talk makes me wonder what I am getting.

Do all these talks of transformers also apply to preamps? I mean, Preamps like GML have no transformers, but I think they sound very honest yet maintain the spirit of the players.

Don't any transformers add some minor harmonic distortion?

If being transparent and yet vital, full, life-affirming is desired, aren't we seeking nearly invisible, yet vital and rich converion from vibrations of air though some wires, and back into vibrations in air?

Why does it seem that every stage of the input and output has to add their own notes (distortion) to the composition?

I am humbly trying to understand this, but it all seems to say that "sexy" mics are ones that make the singer more or less than who she really is.

Do we want that?

IMO, many of the mic pres out there are distortion boxes, pure and simple. Are mics the same way? I do not know, I am asking honestly. Distortion can be good, but only if you are really looking to cover up content, yes? Or dress it up in your own complimentary way?

And, what is wrong with So-called sterile mics or pres? Does that not indicate the absence of distortion? We have plent of distortion boxes in the band, dont need more at the desk?

I'm no expert (in your field), just asking questions that any band might ask.

--KT

[ted nightshade]

There's distortion that adds harmonics, and distortion that kills harmonics- the latter could seem "sterile". It's still distortion.

[Klaus Heyne]

Quote:

Kurt Thompson: Do all these talks of transformers also apply to preamps? I mean, Preamps like GML have no transformers, but I think they sound very honest yet maintain the spirit of the players.

I principal, yes. Only less so, because of the relative signal strength of a pre's output.

The hypothesis (as if anyone can ever go much past speculation or hypothesis with the primitive verification tools we have in audio):  As the signal gets beefier, it's thrown less off course by lousy components or bad circuitry design than with the same lousy components in a mic where the signal is still weak.

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Don't any transformers add some minor harmonic distortion?

Yes, so does every other component in a mic circuit.

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If being transparent and yet vital, full, life-affirming is desired, aren't we seeking nearly invisible, yet vital and rich conversion from vibrations of air though some wires, and back into vibrations in air?

Absolutely. The question is: how do we do that?
And: how do we know when we are getting closer, or when we are getting further away from that ideal?

I had an interesting conversation at a party (there is still such a thing) last night with a very bright software/OS developer who was incredulous about my nontechnical approach to fine tuning a microphone (i.e. listening to my voice, judging what I just heard, implementing a mechanical or electronic change, then listening again, and so on)

Why, he asked, can you not just compare the wave form pictures of a prerecorded signal before and after the microphone, and then know exactly what it is that the mic added or took away from the original sonic event?

It took me twenty minutes to explain to him, that the vital, actionable ingredient of such a test will always be missing, namely how to reliably and repeatedly correlate from a simple graph that shows frequency, volume and, maybe, third harmonic distortion, to the item(s) inside a mic that will affect the sound positively or negatively.

We simply give our current ability for technical, objective analysis of a sensory event way too much credit.

Quote:

Why does it seem that every stage of the input and output has to add their own notes (distortion) to the composition?

Because we don't know any better and invest way too little time and credibility in ear training and analysis. See above.

Quote:

...it all seems to say that "sexy" mics are ones that make the singer more or less than who she really is. Do we want that?

'Sexy' is about as unscientific a word as you can find; still, every time I have used it, it's understood pretty much always in the same sense- a mic's ability to translate the original sound event with its musical, emotional message intact.
And, yes, that's what I do want.

Quote:

...what is wrong with so-called sterile mics...Does that not indicate the absence of distortion?

No. it indicates the absence of life and musicality. The most important ingredient that went into the box did not come out the other side:
Musicality, or, the ability of the mic to process the dynamic and tonal complexities of the original event in such a way that it pulls the listener in.

I think we have to abolish our mental approach to understanding how a microphone (or other important reproductive audio components) processes audio.

Achieving good results from a processor of sensual information is not the same as achieving optimal results from an inanimate object . This type of processing is not as linear as, for example,  a straight-forward calculation of cw-wind resistance vs.horsepower/RPM equals top speed of a car.

When I visited a major mic manufacturer's historic photo archive, I commented to my host that there were so many photos showing Mr. Neumann in the 1920s, 30s, and 50s with headphones. "He used his ears for all important design decisions of  his microphones" was the one sentence answer from my host whose father worked side by side with Mr. Neumann.

In the continued absence of any progress in measurement technologies for sensual converters, we need to get back to how Mr. Neumann arrived at good sounding microphones.

Kind regards

[David Bock]

Lots of meat in this topic.

Quote:

Hello, Oliver. If I've done my sums correctly, the curves shown in your BV 8 graph would represent ca. 126 dB SPL for a U 47 in its cardioid setting. The sensitivity of the U 47 is given variously as 2.5 and 2.8 mV/microbar, and 1 microbar = 74 dB SPL. 1 Volt / 2.5 mV = 52 dB, and 52 + 74 = 126. But I can't find any direct statement of the maximum SPL for the U 47. I gather that it could handle something like 122 - 125 dB SPL without severe overload, but that's only a surmise from indirect statements in Neumann's and Telefunken's literature. Gotham Audio gave a 1% THD limit of 110 dB SPL at one point, but that's just the start of the famous gradual overload region, no? Not an ugly, spattery, bipolar-transistor-style clipping.

Good to differentiate between different TYPES of measurable distortion, the exact spectra matters and no one ever talks about it. BUT, this SPL discussion is almost moot since SPL measurements of the amp only (the published spec) is made in RMS and music is never RMS, unless you're at a Philiph Glass organ concert...so the numbers don't really match up to most in use conditions.

Quote:

Low end distortion... transformer or not transformer...How do you explain the success of the U47FET on kick drum and percussion with heavy low end? I hear no distortion at all. Or is it a pleasant saturation?

The 47fet had a built in HPF that's always active, so the LLF that usually saturates even a nice size xfmr like the one used in that mic never even gets there to saturate it. What you're hearing that you like in that mic is all above 50Hz, well out of the danger range for core saturation.

Quote:

Is there a real technical possibility of having a big old boat anchor mic output transformer on the floor and the capsule up wherever it needs to be? Just curious...

Absolutely!

Quote:

I have made tests with Neumann Fet mics, where I fed a (yes, sinewave!) signal into the mic's processor BEHIND the FET. And low and behold, the headroom is extended by tens of decibels, without any complaint from the transformer.

This is not a valid test as it makes no accounting for in circuit behavior & impedance issues. this test turns out to be more complicated than it appears on  the surface.

Quote:

Klaus, this is not accurate. Dan Wallin uses TLM170s, Sennheiser MKH40/80/800, TLM50 and SM69 (not a small diaphragm). Armin Steiner uses primarily MKH40/80/800. Some examples of their work are "Seabiscuit", "Finding Nemo", "Far From Heaven", "The Road To Perdition" and (Pixar's soon to be released) "The Incredibles". Ironic, since these two represent the 'old guard' of orchestral scoring mixers here in L.A., yet both embrace the modern transformerless designs. Dan--who has been an audio professional since before the L.P.--thinks transformerless was one of the best things to ever happen to microphones.

This could be an example of taste. Some people think Neve 1073's make a great outboard mic pre. I'm shocked and awed (in the bad way)by that, since I know we can do better. Way better.

Quote:

And he thinks of TLM170s as a modernized version of the U-67, a mic I have also seen him use, and use quite happily, when there were no TLMs available.

While I certainly am in no position to critisize your friend, I hope you're not asserting that they sound the same, we all know they don't, and shouldn't given that they have completely different EVERYTHING except the Neumann badge.

Quote:

Maybe there should be a new topic: When using first class electronics, what less destructively conveys the sound of the source: transformers or transformerless?

Please see my post in the other "tranformers" thread, you can't separate the "electronics" from the "transformer", they work as an interactive system, so you either have xfmr or xfmrless.
It's good to see that audio remains a complex field.
Regards,
David Bock

[maarvold]

Quote:

...the absence of life and musicality. The most important ingredient that went into the box did not come out the other side: Musicality, or, the ability of the mic to process the dynamic and tonal complexities of the original event in such a way that it pulls the listener in.

Klaus, (imho) this is an extremely valid point-of-view illustrating, what--to me--is a big part of what is driving this discussion.  Should engineering be documentary, docu-drama or enjoyable fiction?  My current thinking is: documentary first, then whatever is required for the project after that.  

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Some people think Neve 1073's make a great outboard mic pre...

Enjoyable fiction (for many)?

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I hope you're not asserting that [the TLM170 and U-67] sound the same

No, Dan's primary scoring mic for many years was U-67; for the last decade or so it has been TLM170; one tool largely replaced the other.  

Quote:

Quote: Maybe there should be a new topic: When using first class electronics, what less destructively conveys the sound of the source: transformers or transformerless? Please see my post in the other "tranformers" thread, you can't separate the "electronics" from the "transformer", they work as an interactive system, so you either have xfmr or xfmrless.

It goes to show that one can't assume anything.  OK, how's this: When using neutral, transparent mic preamps and associated line level electronics with proper grounding technique, quality cabling, and using input and output impedance matching techniques that won't compromise the performance of the various parts of the signal chain, what microphone design less destructively conveys the sound and/or 'vibe' of the source: transformers or transformerless?  Pretty long for a thread title, but it does illustrate that audio, when attempting to discuss say what we mean, IS complex.  

[Klaus Heyne]

Quote:

There is not a single first call L.A. scoring engineer who does not have a palette of transformer-coupled spot SD condensers in his arsenal.

Yes, I needed to be called on that claim. It's plain stupid and pretentious. As if I know what all or most of the first call scoring engineers have in their mic closet.

What I should have said was:

There is not a single first call L.A. scoring engineer I know, who does not have a palette of transformer-coupled spot SD condensers in his arsenal.

My apologies.

[Plush]

This is a great discussion. However, I believe that
theory sometimes gets in the way of actual results. I do not
believe that quality transformers degrade the sound to a
discernible degree.

For example, compare the original Bruel & Kjaer 4006 omni with a transformer to today's version---the DPA 4006 without the transformer. They basically sound the same on the same source---even low organ notes. There is no saturation there that the ear can discern. Likewise with M50---frequency response extends right down to the lowest fundamentals--it even boosts them! Again no distortion!

Cost issues certainly bear on design considerations. However, the ability of a transformer to correctly interface with the mic amp is still unsurpassed. Also, many preferred mic amps use transformers--some of them very large--ie. Focusrite and E.A.R. (de Paravicini.) Are these ruining the sound by distorting on the low end? The answer is NO.

Small diaphragm mics could include a proper (Jensen like) transformer. It could be built into the larger than the mic diameter connector. I wish Schoeps or Neumann would do this design once again. The Germans will laugh at my suggestion, but thier prior art suggests that they already had it right ages ago.      

[maarvold]

Quote:

Yes, I needed to be called on that claim...

Klaus,

It is EXTREMELY COOL that you 'owned' this.  Not because I consider myself the 'policeman' of LA scoring mixers' mic lockers; rather because people who are searching for truth must be willing to accept real information when it comes their way.  This you graciously did.  So very cool.  

Mike

P.S. I was recording a jazz trio with female scratch vocals recently.  The vocalist and her husband brought their 'Klaus' U-67, black 1176 and a Groove Tubes ViPre.  The vocal sound was fantastic.  Sexy and expensive-sounding.  

[David Bock]

Quote:

OK, how's this: When using neutral, transparent mic preamps and associated line level electronics with proper grounding technique, quality cabling, and using input and output impedance matching techniques that won't compromise the performance of the various parts of the signal chain, what microphone design less destructively conveys the sound and/or 'vibe' of the source: transformers or transformerless?

Good question. In terms of real accuracy, I'm leaning towards the xfmr, since the combination of cumulative impeadance buildups in xfmrless tends to bunch up in the upper mids, the better xfmrs don't. I'm not saying xfmrless CAN'T do it, I just haven't seen or heard it do it yet. BUT, the xfmr model that is high headroom low distortion musically accutrate is no easy task, though it has been done it is not in common mics. An example of 'vibe' as it relates to AE: alot of my favorite vocals are horribly distorted (Motown, Aretha Franklin), would I like them less if they were really capturing the event with a much less obvious signature of the recording process? Not sure, so I'll just count that as one side of the "engineering compromise" see-saw.

Quote:

For example, compare the original Bruel & Kjaer 4006 omni with a transformer to today's version---the DPA 4006 without the transformer. They basically sound the same on the same source---even low organ notes. There is no saturation there that the ear can discern.

The xfmr in that mic rolls off below 20Hz (measurably), but the capsule already has limited response bleow 20Hz @ distances of greater than 3', so it may be hard to discern a difference between the two. I'm sure if we stuck the two on a bass cabinet at a Primus concert we could hear differences.

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Likewise with M50---frequency response extends right down to the lowest fundamentals--it even boosts them! Again no distortion!

The electronics of that mic go to 30Hz w/ a bump before rollof, so it sounds bassier than it is. That LF resonance is part of what everyone (?) likes about those old Neumanns.

Quote:

Also, many preferred mic amps use transformers--some of them very large--ie. Focusrite and E.A.R. (de Paravicini.) Are these ruining the sound by distorting on the low end? The answer is NO.

The Focusrite input xfmrs weren't so large, and the output xfmr had a torrioid which many AE's have questioned (at least on the console we installed @ Oceanway) for "soft" bass. The EAR mic pre, however, does have the largest in and out xfmrs you can buy in a mic pre, specifically to bring the LF cutoff all the way doewn to 5HZ. Larger core sizes allow for lower cutoff freq's and higher core saturation levels- so it's generally going to improve the low end when you increase the core size. The trick is maintaining good HF performance in a large core- some thing the EAR does do.

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Small diaphragm mics could include a proper (Jensen like) transformer.

Why that brand? There are others.....

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The Germans will laugh at my suggestion,

I think it might be more of a "HAH!" than a "laugh".
reggards,
D.Bock

[volki]

while following this thread, several questions arose in my head,  so here i'm dumping all of them now  

Quote:

As the signal gets beefier, it's thrown less off course by lousy components or bad circuitry design than with the same lousy components in a mic where the signal is still weak.

klaus, what exactly do you mean by "weak"? low voltage? i mean, later on in the recording chain, a signal is often (partly strongly) attenuated and amplified again, too...
at least regarding passive components, your statement could mean that parasitic elements can do more harm to a "weak" signal than to a strong one - probably capacitors and xformers being the most important factors here?

Quote:

Microphone designers do not have the choice these days, all off the shelf transformers do not work in classic nor in modern microphone design at all, due to lack of proper lamination or raw material for small size x-former. The Neumann transformer used in the KM5x series were the last time a high headroom small size x-former was build, the main limitation was the AC701k, but the cost insensitive finally stopped their usage.

lamination - do you mean the winding "topology"?
material - so there are (were) special alloys/insulations etc. necessary to manufacture these xformers?

Quote:

(from the preceding thread "transformers in microphones - an advantage?") Unfortunately most transformerless condenser microphones do not use this approach, however; they take a lower-cost approach, which is to drive only one modulation lead while connecting the other one to signal ground through an "equivalent" impedance (which one hopes will keep its equivalence at frequencies beyond the audio frequency range). As far as I'm aware, all of Neumann's transformerless mikes use that approach rather than full output symmetry.

"equivalent impedance"? could someone explain that approach a bit? so there's no balancing amp in there at all? wow... and still decent (well probably not great) cmmr? even ok rfi-rejection?

best regards,

[Klaus Heyne]

Only one of the quotes you cite in your post came from me, so I'll stick to that one.

Right up front-  I deal in speculation; currently, there is very little chance that my theories or hypotheses can be confirmed in any sure way, due to the lack of adequate testing devices.

By 'weak' signal I mean that, despite transients that can reach into single volts, the average condenser mic output level is about 20-40dB below the (line) level of the next stage in the recording chain. In addition, very little current, in the low milliamperes, flows through a microphone.

As such, my impression is that the quality of a specific component (transformer, transistor, tube, capacitor, resistor, etc.) and the circuit's layout are more readily detectable by ear than in the next stage, where more current and more voltage flows.

There are two other differences which make it easier to detect artifacts in a microphone than in a, let's say, mic pre:

1. less circuitry and components

2. less confusion from which component in the audio chain any artifacts may come from, as the mic is at the beginning of the chain, so, ideally only minimal componentry (to drive a pair of  highly efficient head phones) would be needed to hone in on the source of the artifacts.

Kind regards,

[Oliver Archut]

My original quote regarding x-former points out the current situations in the x-former market, here in the US there are only a hand full of lamination and core materials left, 50 years there were about 50 to 80 different core alloys and nearly three times as many lamination sizes. Same with german/european lamination.
With the uprise of DC/DC converter the market gets smaller and smaller each year. Also there is audio Ni/FE (high nickel alloy)lamination with a round loop, and the square loop for puls application (that sounds harsh if used for audio).
My prediction is that with in ten years there are no audio laminations left.
Transistor x-former use M6 lamination the same that is used for power x-former so they might be around a bit longer....

Hope that's answers you question...

Regards,