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Logic behind tube vs regular mic sound difference?
Old 4 weeks ago | Show parent
  #211
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Quote:
Originally Posted by DougS ➡️
You're dumbing yourself down purposely to serve your agenda.
He's cornered.
Old 4 weeks ago | Show parent
  #212
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🎧 10 years
Quote:
Originally Posted by DougS ➡️
You're dumbing yourself down purposely to serve your agenda.

Record a repeatable signal - swap tubes - Record again. Splice them together in one second intervals, listen.

You've already stated in this thread that hearing a difference between two signals alternating by 1 second meets your definition of an audible difference.
This has been discussed in another thread. Getting an exact repetition of an acoustic signal into an out of a mic is nearly impossible. Then you're doing a fully sighted comparison, which is a proven bias. The test is flawed and best.
Quote:
Originally Posted by DougS ➡️
Below is the first line of this thread and the question at hand:


The only way a tube can have no impact on the sound is if its totally issolated from in the signal path. Thus, if I put a noisy tube in and the mic gets noisy I've confirmed its not isolated. End of debate.
The question was in context of how much the tube contributes to the sound of a tube mic. It's not possible to isolate it. Installing a tube that is outside of the design parameters of the mic doesn't prove anything except that the tube is inadequate. And the same can be said for SS mics.
Quote:
Originally Posted by DougS ➡️
The fact that you can screw up a FET mic by swapping components has no bearing on the question at hand. But you know that. You're not that confused are you?
lI has an exact bearing. In both tube and FET mics, the active devices is part of the entire mic, with the biggest influences on the total sound being the acoustic components and the transducer itself. If you study transducers alone, you would see that the process of conversion of one form of energy to another is the most flawed element of the total system. The amplifier must be considered as a whole because unless it is whole it's not a functional amplifier.
Quote:
Originally Posted by DougS ➡️

Are you going to tell us the tube makes no difference in a U47 which was made before SS mics were invented? These are still used in studios around the world.
I've never said anything like that.
Quote:
Originally Posted by DougS ➡️
What about the U67 I just bought. Its essentially an exact copy of the circuit that came out in the original in 1960. You think they were using tubes as a marketing gimmick in 1960? The first commercially available FET mic would not come out for another 6 years. Neumann's U47 Fet didn't come out for another 12 years ('72). Folks have dissected the 67 re-issues side-by-side vintage 67s from the 60's confirming they are to a very high degree the same circuit.

To that point, the circuit of every tube mic released (especially high-end) is poured over and examined. When folks find the tube is just 'decoration' it comes out pretty quickly. That happend with a channel strip a few years ago. If you don't have the talent yourself, just hire someone who does to examine a few tube mic circuits. But you know that also - you're insistence on blackbox testing serves your agenda.
There is no such thing as "blackbox" testing. I'm not insisting on anything. The test methods outlined are not adequate to prove anything. But it may not be necessary to prove anything. You like your tube mic? Perfectly fine with me. I like them too. The only question is how much of what we like is the tube, and all I'm saying is we can't tell.
Quote:
Originally Posted by DougS ➡️
Besides, the marketing guys don't need fake tubes to sell stuff.
No, but marketing is based on impression, and impression is not based only on something audible.
Quote:
Originally Posted by DougS ➡️
They're selling software that "sounds like" tube mics. Haven't used it myself but they sound pretty good in samples.
Sure, but you can't exactly replicate a mic of any kind in software because a mic is in a 3D acoustic space with highly variable characteristics based on its polar pattern, and software simulations can only deal with one axis, straight on. So they're good, but not exact.
Old 4 weeks ago | Show parent
  #213
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🎧 15 years
Quote:
Originally Posted by jaddie ➡️
What is a “repeating source”?

The test is fully sighted, and therefore biased.

Doesn’t matter anyway, even if tubes did change the sound, you could do the same test with swapping FETs.
By a "repeating source"...I mean a source that doesn't change from one take to the next. Something as basic as a reamped guitar track, or anything else for that matter.

AFA the "fully sighted"...it's pretty easy to have someone flip through the tracks while you listen with eyes closed...assuming you don't think you can trust your ears and eyes working together to pick something without bias.
I understand that a certain amount of bias can be there if you're looking at what tracks you are picking...but honestly, if you're trying to pick which tube sounds best out of several...you're not going to show bias for a particular tube.
If you flip back-n-forth enough times, your ears shouldn't be lying to you...even if you have "tube favorites".

So then...since you say "even if the tubes did change the sound"....does mean you admit it's possible...?
Old 3 weeks ago
  #214
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When the OP suggested such a test you enthusiastically embraced it.

Quote:
Originally Posted by jaddie ➡️
Quote:
Originally Posted by kraku ➡️

In other words:

I take a tube mic.
I screw it in one place so it won't move at all.
I play a digitally reproducible test signal into it and record it.
Then I take out the tube and replace it with transistor/opamp/whatever electronics which does the same thing as the tube electronics did.
I record the exact same test signal again.
I compare the results: what do I hear? Will there be any kind of perceivable difference in there at all?

Judging by the graphs there shouldn't be, unless I drive the signal through a tube distortion box?
You should try it. Seriously.
A later followup
Quote:
Originally Posted by jaddie ➡️
But fundamentally, the OP is asking if device data is very similar, why should there be a difference in tube vs SS mics. It's a valid question, also easily answered (see my last post).
But when I suggested the same you went on at length about how its impossible to execute such a test.

Quote:
Originally Posted by DougS ➡️
Record a repeatable signal - swap tubes - Record again. Splice them together in one second intervals, listen.
Quote:
Originally Posted by jaddie ➡️
This has been discussed in another thread. Getting an exact repetition of an acoustic signal into an out of a mic is nearly impossible. Then you're doing a fully sighted comparison, which is a proven bias. The test is flawed and best.
Care to explain?
Old 3 weeks ago | Show parent
  #215
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Quote:
Originally Posted by miroslav ➡️
By a "repeating source"...I mean a source that doesn't change from one take to the next. Something as basic as a reamped guitar track, or anything else for that matter.

AFA the "fully sighted"...it's pretty easy to have someone flip through the tracks while you listen with eyes closed...assuming you don't think you can trust your ears and eyes working together to pick something without bias.
I understand that a certain amount of bias can be there if you're looking at what tracks you are picking...but honestly, if you're trying to pick which tube sounds best out of several...you're not going to show bias for a particular tube.
If you flip back-n-forth enough times, your ears shouldn't be lying to you...even if you have "tube favorites".
The description above does not result in a test with enough controls to discern small differences. Please study double blind testing, how it’s done and why it’s necessary.

Quote:
Originally Posted by miroslav ➡️

So then...since you say "even if the tubes did change the sound"....does mean you admit it's possible...?
Please understand, I am not now, nor have I ever said that tube mics didn’t have their owns sound. But so does every mic, all technologies. The mic is a complete system, acoustic, electro-acoustic and electronic. The biggest factors in any mics sound is the acoustic design and the transducer. But it’s a complete system. There are many pieces that cannot be accurately analyzed as to their portion of the whole. The gain element is one of those pieces.
Old 3 weeks ago | Show parent
  #216
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🎧 10 years
Quote:
Originally Posted by DougS ➡️
When the OP suggested such a test you enthusiastically embraced it.



A later followup


But when I suggested the same you went on at length about how its impossible to execute such a test.





Care to explain?
Sure. The difference lies in the intent. I always encourage people to try things they will learn from. The OPs intent was to learn. You implied you’ve done that test, then attempted to use your entirely subjective and biased opinions to prove something that is unprovable that way, in a secondary attempt to discredit me.

Again, please understand my main points here. Mics of all kinds are complete systems. You cannot quantify the contribution of the minor factors, you only know that certain elements have more well known tendencies to distort the original signal. You are welcome to attribute anything you want to the gain device, but in doing so, you ignore the rest of the system which has more than enough capability to contribute the defining characteristics.
Old 3 weeks ago | Show parent
  #217
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Quote:
Originally Posted by Brent Hahn ➡️
He's cornered.
If you’re referring to me, I don’t feel that way at all. But if thinking that somehow helps you, then full steam ahead.
Old 3 weeks ago
  #218
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IMO the problem we (as in everyone, not just folk sitting on one side of a fence) run into in any debate is that any answer has to be remembered in the context of the question that was asked.

Audio Test Kitchen is probably the best that has been achieved and the files are publicly and easily available. They use a repeating source and the speaker vs mic positioning is calibrated with lasers. While the speaker and room influence the sound, they remain constants, and so allow a good comparison between mics. I wouldn't be surprised if they do a tube comparison in the near future. Of course, as jaddie has pointed out, they will need to ensure that the topology used in a chosen mic does not skew the results by being favourable to an out of spec tube. Assuming they know what they are doing, it would highlight tubes that are out of spec. But more interestingly, if for example a long plate tube does give increased bass response compared to source material, then that is something that would be audible. I expect to hear differences between different brands of a tube type (say a 12AX7) if they use tubes that have varying factors such as plate length, and have a similar expectation with different brands of a FET type. However that's the best I think we can expect. From what has been written thus far in this thread, I can't see how they could do a tube vs transistor shootout considering the other components in a topology would affect the sound.

IMO this fence is an artificial construct - it does not naturally exist because we can not audibly isolate a gain device from its topology. I didn't know that when I first came across this thread, but do now, and wonder why it is so difficult for some folk to grok.
Old 3 weeks ago | Show parent
  #219
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🎧 15 years
Quote:
Originally Posted by jaddie ➡️
The description above does not result in a test with enough controls to discern small differences.
It's certainly good enough to discern the obvious differences...which I think is what this thread is about.

TBH...I don't even know what point you're trying to make anymore, or the perspective you're debating from...?
I don't mean that as some personal shot...it's just that you've kinda debated yourself full circle it seems.

Now you say that you never said there aren't any differences...well if you agree that there ARE differences, then why argue that you can't hear them or do basic comparisons to discern them...?

You know...sometimes you just trust your ears, without the need to do have a full-on, controlled electronic laboratory test to tell you what your ears are already telling you...but if that's what you need to do to believe your ears...then go for it.
Old 3 weeks ago | Show parent
  #220
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Quote:
Originally Posted by DougS ➡️

To that point, the circuit of every tube mic released (especially high-end) is poured over and examined.
I should hope not, you’d have quite a fire, or the the very least, a shock!

Today’s password is: “pored”

Last edited by Sharp11; 3 weeks ago at 04:31 AM..
Old 3 weeks ago | Show parent
  #221
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Quote:
Originally Posted by DougS ➡️
When the OP suggested such a test you enthusiastically embraced it.



A later followup


But when I suggested the same you went on at length about how its impossible to execute such a test.





Care to explain?
Just be happy there are people like jaddie around who have the talent and education to design, build, and test the stuff you don’t have a complete understanding of, and get on with what you know; making music.

In my experience, tubes don’t have a sound, as long as the tube in use performs at its proper rating (which many do not) and fits the circuit the designer designed for it, any tube will suffice. I have loads of tubes from different manufacturers sitting around here - old, new, British, Chinese, Russian, American - many of them dead or poor performers.

The whole point of this thread was to reiterate concept that the tube, when functioning properly, fulfills its role as part of the overall circuit - why this obvious conclusion is so hard for some here to comprehend is beyond me, but this is gearspace, after all.

Furthermore, back in the 60s, one of the primary reasons Neumann and others worked so hard to move to fet was the decreasing quality of vacuum tubes, regardless of brand, there were more and more of them failing or not performing up to design goals out of the box - Neumann was losing money by rejecting so many tubes. That situation certainly isn’t any better today.

Last edited by Sharp11; 3 weeks ago at 04:32 AM..
Old 3 weeks ago
  #222
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Just about everything a tube mic does a SS mic can do to near perfection. Until recently tube mics were esteemed relics of the platinum age of audio 1948-1970. But after the mid 60's there were precious few new tube mics made so all tube mics were old and well used. So a tube mic in a studio in 1980 couldn't help but be loaded with mojo. However that little glowing tube in an expensive condenser might not be worth the price of admission in every case. In fact an hour before I wrote this post I took my tube mic down and set up a ribbon mic which sounded better on a certain vocal. Anyway back in the 80's I frequently sang into a U67 with typically Neumann results. But in a sense it was ignorance being bliss. You see one session the U67 was out for service and my engineer set up a Beyerdynamic ribbon mic for me. IMHO it was the best darn mic I'd ever heard and when the Neumann came back I almost came to blows with the studio lads with my insisting to use the Beyerdynamic ribbon mic for the duration of the sessions. So do you need a tube in a mic. Yes if you want a nice toasty warm mic at the end of the session, no for just about everything else. At tis point in time I lean towards ribbon mics. While they don't get to consume that exotic phantom power stuff they are over all pretty exquisite creations.

So about those tube mics......well you will never regret investing in some good tube preamps and amps. This is where tubes really count
Old 3 weeks ago | Show parent
  #223
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Quote:
Originally Posted by miroslav ➡️
It's certainly good enough to discern the obvious differences...which I think is what this thread is about.
You do remember that "you don't know what you don't know" thing, right? So, I disagree. "Good enough" is an assumption. Bound to bite at some point.
Quote:
Originally Posted by miroslav ➡️
TBH...I don't even know what point you're trying to make anymore, or the perspective you're debating from...?
I don't mean that as some personal shot...it's just that you've kinda debated yourself full circle it seems.
I completely agree that you don't even know what point I'm trying to make.
Quote:
Originally Posted by miroslav ➡️
Now you say that you never said there aren't any differences...well if you agree that there ARE differences, then why argue that you can't hear them or do basic comparisons to discern them...?
Yeah, you're not getting it at all.

I'll make one more attempt to simplify.

1. There are differences between mics. Some huge, some not.

2. This thread is about how much the tube is a factor in the sound of a tube mic, not if mics sound differently.

3. Your comparison methods are not scientific, they are subjective and biased. When it comes to discerning audible differences, that's not going to cut it, even if you think it's good enough for you. For those involved in actual science, no.

4. Swapping tubes doesn't prove how much of a factor of the total sound the tube contributes, especially if you're not taking the time to confirm the performance of the tubes is what the manufacturer designed the mic around, and not some old tired original 1953 EF86 pulled out of a rusted piece of hifi gear. Putting in a bad tube doesn't prove how much a good tube contributes to the total performance.
Quote:
Originally Posted by miroslav ➡️

You know...sometimes you just trust your ears, without the need to do have a full-on, controlled electronic laboratory test to tell you what your ears are already telling you...but if that's what you need to do to believe your ears...then go for it.
It has been shown, time and again, that ears do not work alone. Perception is a combination of all sensory input and non-sensory factors like expectation. It has also been shown in controlled testing that if you suggest A is better than B, even when they are actually identical, that's how they will be heard.

But all of this has belief systems at its core. My belief is that hearing alone is not fully trust worthy unless it is isolated from other sensory input and biases. I have arrived at this after decades of testing and experimentation, plus research and study of other's works. Yours is "trust your ears", apparently without any regard for how perception actually But I will debate a strongly asserted opinion if it has little basis in fact or is presented without scientific principles. I was going to say "Sorry about that" here, but I'm not sorry for my opinions, I'm sorry if they upset anyone else though. Truth is important in everything, audio is no exception.
Old 3 weeks ago
  #224
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This thread should‘ve been shot and buried by post #7 .
Old 3 weeks ago
  #225
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Thanks for some very patient and carefully thought through comments Jaddie.
But I need to declare Confirmation Bias here... solid scientific methodology is something I warm too over anecdotal attributions ...
Old 3 weeks ago
  #226
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If I read this entire thread will my gear sound better or worse?
Old 3 weeks ago | Show parent
  #227
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Quote:
Originally Posted by Jeroko ➡️
If I read this entire thread will my gear sound better or worse?
It’s GS - your gear will sound however you want and believe it should
Old 3 weeks ago
  #228
Gear Maniac
Quote:
Originally Posted by kraku ➡️
Do tubes in mics actually color the sound at all?

Take a look at the attached pictures which show the signal curve of a tube and a transistor. They look awfully lot the same. Unless you start driving the tube/transistor (or opamp) into distortion levels, there should probably be zero difference in the sound. None of the microphones I know of drive signal to such high volumes. That's what guitar distortion pedals are for.

In other words:

I take a tube mic.
I screw it in one place so it won't move at all.
I play a digitally reproducible test signal into it and record it.
Then I take out the tube and replace it with transistor/opamp/whatever electronics which does the same thing as the tube electronics did.
I record the exact same test signal again.
I compare the results: what do I hear? Will there be any kind of perceivable difference in there at all?

Judging by the graphs there shouldn't be, unless I drive the signal through a tube distortion box?
One cannot hear graphs, or waveforms on a screen. A disrotion box with a tube in its cicuit is a far cry from a high end tube microphone, nobody's lying to you.

Even a tube bearing the same markings, for instance, a 12ax7 tube, can sound entirely different from another 12ax7. Buy a JJ's 12ax7, and then, a Bugle Boy from Holland from 1950's. Listen to both tubes, and you should hear a remarkable difference.

You should, as has already been suggested, go to a studio which has nice tbe mics, and listen. Hang a TLM 103, patch in a distortion box, and hang a C-12 or a 251 next to it, and you'll hear the difference. If, you cannot discern the difference, you may need to invest more time on improving your listening skills..Definately not saying this in a negative manner.

Listen more, look less. Graphs make no sound.
Old 3 weeks ago | Show parent
  #229
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Quote:
Originally Posted by LLSentelle ➡️
You should, as has already been suggested, go to a studio which has nice tbe mics, and listen. Hang a TLM 103, patch in a distortion box, and hang a C-12 or a 251 next to it, and you'll hear the difference. If, you cannot discern the difference, you may need to invest more time on improving your listening skills..Definately not saying this in a negative manner.

.
This is misleading and poor advice.

Those are two completely different mics with different design goals and circuitry - go drive a Ferrari and a Volkswagen, if you can’t tell the difference between an independent rear suspension and one with a torsion beam rear axle, you may need to spend more time improving your driving skills.

Sigh ....
Old 3 weeks ago
  #230
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Quote:
Originally Posted by kraku ➡️
Do tubes in mics actually color the sound at all?
Yes.

How tubes and solid-state electronics work differently to each other and alter the sound with harmonics is established science fact.

Tubes were used originally in classic vintage mics because solid state transistors were not invented or available for general use at the time.

Tubes create extra *pleasant* harmonics in the audio signal which solid state transistors don't and they also distort the audio wave pleasantly and in a musical way when pushed. In addition, pushing tubes will compress the audio signal and shave off some top-end frequencies. In all = perceived 'warmth'.

When several sources record vocals with tube mics, those extra harmonics combine in a very distinctive and highly pleasant way that you can never get with solid-state mics.

Clipping (distorting) solid-state electronics causes audio waves to flatten, sound brittle and distort in a very nasty unpleasant non-musical way and does not generate *pleasant* harmonics the harder you drive them.

* * edited to include what I originally intended.
Old 3 weeks ago | Show parent
  #231
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Quote:
Originally Posted by The Revealer ➡️
Yes.

How tubes and solid-state electronics work differently to each other and alter the sound with harmonics is established science fact.

Tubes were used originally in classic vintage mics because solid state transistors were not invented or available for general use at the time.
Good so far...but...
Quote:
Originally Posted by The Revealer ➡️
Tubes create extra harmonics in the audio signal which solid state transistors don't and they also distort the audio wave pleasantly and in a musical way when pushed.
Argh. No. Wrong. Tubes do not product extra harmonics that transistors don't. You can make functionally equivalent tube and transistor circuits. It's not the tube or transistor, its the entire circuit they are in.
Quote:
Originally Posted by The Revealer ➡️
When several sources record vocals with tube mics, those extra harmonics combine in a very distinctive and highly pleasant way that you can never get with solid-state mics.
Thats the basic definition of one of the worst, non-musical forms of distortion, Intermodulation Distortion. And no, they don't do that any more that a SS device in a well designed circuit.
Quote:
Originally Posted by The Revealer ➡️
In addition, pushing tubes will compress the audio signal and shave off some top-end frequencies. In all = perceived 'warmth'.
No. When tube circuits are pushed into the nonlinear range, they do not shave off high frequencies. If anything, they make high frequencies.
Quote:
Originally Posted by The Revealer ➡️
Clipping (distorting) solid-state electronics causes audio waves to flatten, sound brittle and distort in a very nasty unpleasant non-musical way and does not generate harmonics the harder you drive them.
Again, no. Transistors, particularly an FET in a class A amp, like in a tube mic, doesn't hard clip like that, they mush into distortion slowly. It's a characteristic of the Class A topology. Yes, the "mush" curve can vary, but it can with tubes too. High gain pentodes tend to distort faster than low gain triodes.

Most of the post I'm responding too is classic tube mythology.
Old 3 weeks ago | Show parent
  #232
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Sadly I may have been mislead like most people on this, plus in regard to distorting solid-state devices, I wasn't talking about class-A electronics but my own experinces with nasty 70's solid state guitar amplifiers, a mistake I guess since this is a thread about mics, so sure, mea culpa, but I'm confused about one of your points:

Quote:
Originally Posted by jaddie ➡️

Thats the basic definition of one of the worst, non-musical forms of distortion, Intermodulation Distortion.
I'm listening to The Beachboys Pet Sounds, at the layered vocal harmonies made on the Bill Putnam tube desk with 610-A tube preamps, with tube mics (U47 and 67's I think) pushed into the red as Brian Wilson loved the 'hot sound' he got from the desk, and I can't hear any of that intermodulation distortion and neither can I hear it on any multi-layered vocals in 60's music, so what gives?
Old 3 weeks ago
  #233
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wow I can't believe this conversation has gotten this much attention.
You must have real world studio experience to understand why these glorious old tube mics sound so good.
Throw the charts away and use your bloody ears.
BTW if anyone has some of those old tube mics they want to get rid of... let me know!
Old 3 weeks ago | Show parent
  #234
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Quote:
Originally Posted by Fredtiki ➡️
wow I can't believe this conversation has gotten this much attention.
You must have real world studio experience to understand why these glorious old tube mics sound so good.
Throw the charts away and use your bloody ears.
BTW if anyone has some of those old tube mics they want to get rid of... let me know!
Unfortunately, the thread moves on because of posts like this one, which distort and completely miss the intent of the original poster - who asked a simple question which has been answered a dozen times already - yet, you felt the need ... sigh.
Old 3 weeks ago | Show parent
  #235
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Quote:
Originally Posted by jaddie ➡️
...No. Wrong. Tubes do not product extra harmonics that transistors don't. You can make functionally equivalent tube and transistor circuits....

This is inaccurate electronic information--simply completely wrong.

'Extra harmonics' is not a precise term, but as I mentioned earlier, solid state and tube have different transfer curves and produce different harmonic content as the signal moves away from the most linear portion of the transfer curve.

I don't know what you mean by functionally equivalent, but I can't think of an interpretation of that phrase where it would be true.

Of course the surrounding circuitry is different because the devices are different.

I confess, I have lost the plot a bit here, but this entire thread looks to me to be based on a false premise, so it never completely makes sense.
Old 3 weeks ago | Show parent
  #236
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Quote:
Originally Posted by Fredtiki ➡️
wow I can't believe this conversation has gotten this much attention.
You must have real world studio experience to understand why these glorious old tube mics sound so good.
Throw the charts away and use your bloody ears.
BTW if anyone has some of those old tube mics they want to get rid of... let me know!
Nobody is contesting the idea that old tube mics sound good or not. You must not have read the tread well to get that.

The entire discussion started with the OP wondering what specific contribution to the tube mic sound was attributable to the tube itself.

We aren't discussing if they sound better or not.
Old 3 weeks ago | Show parent
  #237
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Quote:
Originally Posted by The Revealer ➡️
I'm listening to The Beachboys Pet Sounds, at the layered vocal harmonies made on the Bill Putnam tube desk with 610-A tube preamps, with tube mics (U47 and 67's I think) pushed into the red as Brian Wilson loved the 'hot sound' he got from the desk, and I can't hear any of that intermodulation distortion and neither can I hear it on any multi-layered vocals in 60's music, so what gives?
I used to work at a place where the Chief Tech had a knowledge in electronics and audio theory on a par with what you're seeing in this thread. He couldn't hear critically, music and audio had no emotional effect on him, and he used his knowledge like a sledgehammer to try to beat engineers into thinking they couldn't possibly be hearing what they were obviously hearing.

He used this knowledge, for example, as the rationale for swapping out a pair of Pultec EQP1a's in a control room for a pair of Orban parametrics by proving, with the help of a scope and the Orban brochure, that the two Pultecs weren't 100% identical in behavior (true), that they didn't alter the sound by simply being in the chain and zeroed out (false), and that the Orbans were more useful because they could do everything the Pultecs could do plus so much more.

This place had 11 Neumann U47's, and the senior staff mixers could identify most of them blindfolded. The Chief Tech deemed that impossible.

I'm not saying that Chief Tech and this guy are the same guy. But I'm getting a strong echo.
Old 3 weeks ago | Show parent
  #238
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Quote:
Originally Posted by kraku ➡️
Nope, haven't done proper recordings with a tube mic. And that's beside the point here:

If you don't measure the signal and instead only use your ears, you don't know how much the tube affects the signal. The next best thing is to look at the scientific charts and see what's going on there.
Actually experiencing it is the only point.

All the electrical nerve response measurements and all the MIP mapping etc. etc. of having sex with a condom and without,, may chart exactly the same BUT guess what ?
It may be impossible to Quantify any difference, but I can sure as hell Qualify it
I know silly analogy but I am feeling extra cheeky today ...
Old 3 weeks ago | Show parent
  #239
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🎧 10 years
Quote:
Originally Posted by ponzi ➡️
This is inaccurate electronic information--simply completely wrong.

'Extra harmonics' is not a precise term, but as I mentioned earlier, solid state and tube have different transfer curves and produce different harmonic content as the signal moves away from the most linear portion of the transfer curve.
Once again, ignoring the application in favor of a sweeping generality attempted to apply to every tube and transistor ever created.

Of course devices have different curves, that actually was part of my point. But you wouldn't use the highly nonlinear portion of the curve with any device, unless it is corrected with negative feedback. That's not the typical tube mic preamp operation, though. In that application, any device must operate along the most linear portion of the curve, and the correct device must be chosen for it's total gain, noise figure, and be biased to operate in the linear zone. This is true with any active device operated as a Class A amplifier. If you look at general purpose FET curves, you'll find it's difficult to work in the linear portion of the curve, but we don't use general purpose FETs like that any more than you would use a high power pentode that works great as a Class C RF amp, as a capsule buffer. You choose the device that works best in the application, and optimize the circuit around it.

Since you've missed the point....there are many parts of any condenser mic that impact its total performance.

1. Acoustic design
2. Capsule design
3. Preamp design
4. Output stage design

And the above is just very general, there are subsets of each. We're trying to examine the impact of one small piece of the total, the gain device. We're concluding, some of us, that the gain device alone cannot be analyzed individually because it works within a total system and its contributions are relatively small, whereas the transducer, the capsule, contributes a lot, as does the acoustic design.
Quote:
Originally Posted by ponzi ➡️
I don't know what you mean by functionally equivalent, but I can't think of an interpretation of that phrase where it would be true.
A function defines what the circuit does. One function is to buffer and amplify the signal from a mic capsule. Equivalent means "the same". So an example of functionally equivalent would be, a condenser capsule preamp.
Quote:
Originally Posted by ponzi ➡️
Of course the surrounding circuitry is different because the devices are different.
As I've said a few times.
Quote:
Originally Posted by ponzi ➡️
I confess, I have lost the plot a bit here, but this entire thread looks to me to be based on a false premise, so it never completely makes sense.
So, the desire to understand what makes something work a certain way is a false premise?

OK. Nothing to see here. Move along.
Old 3 weeks ago | Show parent
  #240
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ponzi's Avatar
 
🎧 15 years
Quote:
Originally Posted by jaddie ➡️
...So, the desire to understand what makes something work a certain way is a false premise?

OK. Nothing to see here. Move along.
Edit: I think I am being a dick here, so while I stand by my words, it would have been better if I stayed out of it, and I will say no more.
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