Tube mike VS. Mike with tube pre-amp

[Vagodeoz]

Obviously comparing models from the same price range, what's best?
A "regular" mike with a tube pre-amp? or a Tube Mike with a "regular" pre-amp?

 

[Farview]

That's apples and oranges.

Anything less that $1000 with a tube in it isn't going to be good quality stuff. It's more expensive to make tube gear, so cheap tube gear is actually worse than cheap solid state gear.

If you are looking for 'warmth', tubes are not the first place to look. Most of the coveted preamps (neve, api, great river, etc...) and mics (U87, 414, etc...) are solid state.

You choose a mic because of the way it sounds, not by it's circuit topology. Same with a preamp.

To answer your question directly, it depends on which mic and which preamp.

 

[cusebassman]

I generally tend to agree with Farview, but I paid 700 for my Rode K2, and after swapping out the 6922, it sounded much better, which indicates to me that 1) Rode uses cheap tubes (shocking), and 2) that it actually relies on the valve for processing of the audio signal, verses cheap Toob stuff that just adds a starved-plate tube to the end of a solidstate signal path.

 

[antichef]

But you know, before the group buy just now, I was always about to ask the question whether you needed a preamp with a tube mic, because I wasn't sure what function was being performed by the tube in the tube mic (was there a preamp *in* the mic? - you know). Now that I got the ACM-6802T and ACM-310 (which, to my unsophisticated ears, sound pretty good, even though they were less than $100 ), I can see that the signal coming out of them is on the same order of magnitude as the signal coming out of my other non-tube condenser mics. So, I suppose the tube in the tube mic is doing the same job as the transformer or FET in the other mics -- it's not working as a preamp, or at least, not boosting the signal to the same level as what I call a preamp.

So... apples and oranges, but I was really wondering about that until I got my hands on one.

My goal now is to keep myself from hearing the high end tube mics so I can keep gawking at the ones I have

 

[craigmorris74]

So, I suppose the tube in the tube mic is doing the same job as the transformer or FET in the other mics -- it's not working as a preamp, or at least, not boosting the signal to the same level as what I call a preamp.

The tube NEVER has the same function as a transformorer in a microphone. And yes, if the tube is doing it's job in the mic, it is amplifying the signal (but not up to line level obviously).

To the original poster, I suggest buying good mics and pres regardless of their amplification component (tube, IC, transistors) and get over the tube mania. That way you won't be coming back on this forum in a couple of months telling people about how your Art Tube MP blew away a John Hardy and a Neve during a recording session. It seems folks who are new to the game and have the tube mania never buy REAL tube gear (high voltage, transformer balanced). If you insist on a tube pre, check out the Groove Tubes Brick, or the Universal Audio Solo 610, about the cheapest pieces that implement tubes properly on the market now.

If you're decent with soldering and electronics, you can make several of the cheap tube mics out there sound good with modifications to the tube, capsule, transformer, and key capacitors. There are one or two cheap tube mics around here that people swear by, but I've yet to hear their virtues.

Remeber, keep repeating to yourself, "there is no such thing as toob sound..."
Believe me, I was a sucker once and fell for it myself.

Craig

 

[dgatwood]

The tube NEVER has the same function as a transformorer in a microphone. And yes, if the tube is doing it's job in the mic, it is amplifying the signal (but not up to line level obviously).

Well, depends on what you mean by the function of the transformer. A transformer can do two things: drives the outputs and change the gain of the signal. In a dynamic mic, the transformer boosts the gain significantly, and in a ribbon mic, doubly so. So from that perspective, the tube does at least partially replace the transformer's function.

As for driving the outputs, though, you're right. AFAIK, tube mics always use either a transformer (which is typically low gain) or a FET to balance the output.

 

[craigmorris74]

Good point, especially in regards to ribbons and dynamics. I was in the condenser mindset.

Well, depends on what you mean by the function of the transformer. A transformer can do two things: drives the outputs and change the gain of the signal. In a dynamic mic, the transformer boosts the gain significantly, and in a ribbon mic, doubly so. So from that perspective, the tube does at least partially replace the transformer's function.

As for driving the outputs, though, you're right. AFAIK, tube mics always use either a transformer (which is typically low gain) or a FET to balance the output.

 

[pylet2000]

Just to play devils advocate here...

If every other variable were equal, a tube driven device would sound "better" than a transistor driven device. More correct, it would sound different, and when things sound different you get personal preference, and in comes the debate. But it's kind of a silly statement, given the broad generalizations we're making.

I think the main point is that properly designed tube devices are pricey, and the prevelance of cheap tube contraptions on the market along with marketing hyperbole has created some well deserved anti-tube sentiment. And in that light, it's true to say that the common 'toob' junk running around is glorified and overpriced junk. If solid state gear were as poorly designed and as poorly outfitted as the low end tube stuff, it would also sound like trash.

But in comes my opinion on the matter, a proper vacuum tube driven device that is designed well and made with decent components will sound better than well designed, well outfitted solid state device. Audio is the only area where the vacuum tube excels over the transistor, to my ears at least.

I've built a simple (but properly outfitted, read $$$) tube hi-fi amp that sounds better than many solid state hi-fi amps (again, to my ears, there are folks that swear by solid state hi-fi and that's fine), and it comes down to subtle dynamics and smoothness, things that seem to get lost in the physics of solid state amplification. Solid state hi-fi tends to sound VERY clear and defined. Tube amps can sound 'smoothed over' in comparison, but overall in the spirit of recreating a musical performance I think tubes do a better job of conveying the performance energy nuances in the mid range.

The sad thing is that it requires the knowledge to build your own tube contraptions (expensive) or LOTS of money to buy the well designed tube gear (VERY expensive). And given the condition of the vacuum tube market, mixed in with the cheap tube resentment, I think we can see the writing on the wall for where the vaucuum tube is headed, at least commercially...

 

[mshilarious]

The tube NEVER has the same function as a transformorer in a microphone. And yes, if the tube is doing it's job in the mic, it is amplifying the signal (but not up to line level obviously).

Yes, the tube is amplifying, but mainly in the strict sense: adding amps (or mA, more likely).

The basic job of the tube is to provide a buffer for the extremely high-impedance condenser mic capsule. Another way of putting that is impedance conversion, or simply current gain.

While a tube can (and often does, but see below) add voltage gain, that is not the main function of a tube in a microphone. After all, large diaphragm condenser capsules are very sensitive and put out plenty of voltage--just very very little current.

So it's not exactly proper to say that a tube mic "amplifies the signal, but not up to line level", since the main job of the mic's amplifier circuit (whether FET or tube) is not to provide voltage gain.

The job of transformers in microphones is very different according to the type of microphone. In a dynamic mic, it will be a step-up transformer. That's because a dynamic capsule is low-impedance (like a speaker) and low-level. The transformer adds volts at the cost of amps. So you have a mic-impedance output at a higher level than the signal straight off the capsule.

In a condenser mic, it's usually the opposite: a step-down transformer. These are very common in tube mics, because despite what I said above, tubes used in mics are better at voltage gain (although there is also significant current gain, and we could argue about plate vs. cathode design, etc.), so the tube will increase the level somewhat, which is given back in the output transformer. This is necessary because the tube output impedance is still kinda highish (tens of Kohms, still better than many, many megs!), so the transformer converts that extra voltage into extra current, for the required low output impedance.

Of course, the tube could simply be followed by a solid-state stage, which wouldn't lose the voltage like the transformer does, but: a) that would be a really hot output signal, and b) transformers are cool

 

[mshilarious]

Audio is the only area where the vacuum tube excels over the transistor, to my ears at least.

Also high-power radio transmission! But it's kinda hard to hear that directly

I've built a simple (but properly outfitted, read $$$) tube hi-fi amp that sounds better than many solid state hi-fi amps

It could very well sound better, but a simple tube power amp is likely to have either low output, very high distortion, or a combination of both. Of course, it's good distortion, and that's what you like.

Tube mics tend to have to have much lower distortion figures, since they are published as the basis of the mic's power handling spec (at 1% THD). I used to make a tube mic that had 1% distortion pretty much at any level. It made it hard to list a spec . . . sounded good though

The sad thing is that it requires the knowledge to build your own tube contraptions (expensive)

The only thing truly expensive about tube designs are the transformers. Maybe the tubes if you pick something exotic, but I don't see the need. The cost of a good output transformer could choke a horse!

And given the condition of the vacuum tube market, mixed in with the cheap tube resentment, I think we can see the writing on the wall for where the vaucuum tube is headed, at least commercially...

I really don't think so. The people that don't like toob gear don't buy it, they buy high-end tube gear or high-end solid state (which I think you are underestimating).

The people that want a $100 tube amp buy it, maybe they are unhappy later, maybe they aren't.

Whatever their relative value, there remains a market for both.

 

[cusebassman]

I still want to know if anyone has looked at the design of the K2 and determined that it is using its 6922 properly, or if it is like most other cheap toob garbage. Doesn't really matter since I like the sound of it so much, but for curiosity' sake, I'd like to know

Time to google and see if there are any known K2-specific mods... mwahaha

 

[mshilarious]

I still want to know if anyone has looked at the design of the K2 and determined that it is using its 6922 properly, or if it is like most other cheap toob garbage. Doesn't really matter since I like the sound of it so much, but for curiosity' sake, I'd like to know

I would have to think it would be extremely rare for a tube mic to run far out of spec. I mean once you go to the trouble of an external power supply, there is little to be gained from cutting the voltage . . . you can always measure the voltage at the supply pins and see.

 

[Vagodeoz]

Wow, a lot of technical answers hehehe but you guys cleaned up some serious doubts I had.
In my original post what I meant was:
Recently I have been getting into the analog part of recording, and I love a good analog sound (Pink Floyd...).
So, if I was looking for an "analog" or "tube" sound or whatever you want to call it. (you all know what I'm talking about)
Would it be better... let's say... a 3000$ Tube Neumann with a 2000$ Non-Tube Pre-amp? Or a 3000$ Neumann with a 2000$ Tube Pre-Amp?
I know "better" is relative, but I would like to know the difference in sound and performance that the tube makes in different parts of the gain stage.

Obviously those prices aren't within my budget (I barely have an Art Studio MP), but it seems that figures for 1k$+ tube gear are totally different for 1k$- gear.
Anyway, in my case it would be something like comparing one of the cheapest MXL tube mikes ($200) with a cheap LDC (Behringer B2-Pro) with my Art Tube MP (or maaaybe in the future, a Studio Projects VTB1)

 

[Farview]

If every other variable were equal, a tube driven device would sound "better" than a transistor driven device.

"better" is, of course, subjective. It's no secret that almost all of the most coveted mic preamps are solid state. Neve doesn't hve a tube model, nor API, Trident, great river, etc...

In fact, I'm hard pressed to name a tube preamp that has that kind of history. The vipre is really good sounding, but that showed up less than 10 years ago.

 

[mshilarious]

Anyway, in my case it would be something like comparing one of the cheapest MXL tube mikes ($200) with a cheap LDC (Behringer B2-Pro) with my Art Tube MP (or maaaybe in the future, a Studio Projects VTB1)

Well, I don't have personal experience with MXL's tube mics, but I do know that mods are very popular. And that makes sense; if you have two mics from MXL that cost $200, one is tube and one is not, which is likely to have better parts? The tube mic has to have a tube, a transformer, a special cable, and a power supply. Those are expensive parts. So the $200 FET mic might just have better parts, maybe a better capsule (although maybe not). If you take the tube mic and swap the tube for something better, clean up the power supply, etc., then you'd have the equivalent of maybe a $400 tube mic.

But if you want something out of the box for $200, I know there are plenty of decent FET mics in that range . . .

 

[Vagodeoz]

Well, I don't have personal experience with MXL's tube mics, but I do know that mods are very popular. And that makes sense; if you have two mics from MXL that cost $200, one is tube and one is not, which is likely to have better parts? The tube mic has to have a tube, a transformer, a special cable, and a power supply. Those are expensive parts. So the $200 FET mic might just have better parts, maybe a better capsule (although maybe not). If you take the tube mic and swap the tube for something better, clean up the power supply, etc., then you'd have the equivalent of maybe a $400 tube mic.

But if you want something out of the box for $200, I know there are plenty of decent FET mics in that range . . .

Makes sense... but doesn't it works the other way around with pre-amps?
The tube pre-amp will also need a tube and some extra stuff I have no idea about.
So let's say... a DMP3 (about 150$ for two channels, it's supposed to be the best pre-amp on it's price range) vs a Studio Projects VTB1 (which is about 120$ for one channel, and it's supposed to be the best tube option at it's price point)

So a "cheap" MXL tube with a "good" Dmp3, or a "good" MXL non-tube mike with an ART Tube MP... hmmm...

Too bad there aren't any tube mikes below 200$, so I could easily try this by myself. The only exception was the MSH-4 (RIP).

Edit: I just made a poll on the analog forum that has a lot to do with this topic.

 

[craigmorris74]

A couple of times now, tube has been equated with better, and I really think that's a bad precedent. But, I will agree that when it comes to bang for your buck solid state is the way to go.

If you want Pink Floyd, all their (post SOS) records were recorded on solid state desks.

 

[Vagodeoz]

I want old pink floyd (atom heart mother), beatles, the doors...

 

[cusebassman]

I would have to think it would be extremely rare for a tube mic to run far out of spec. I mean once you go to the trouble of an external power supply, there is little to be gained from cutting the voltage . . . you can always measure the voltage at the supply pins and see.

Thanks for the prespective. I am rest-assured in my discovery (from a year ago when I bought it), that it is "true tube" since swapping out the stock for a nice Telefunken made a pretty noticeable difference in sound, and as you say, why go to the trouble of building around a power supply if its going to run starved anyway... "for appearances" only goes so far - I would imagine anyone buying a valve-based mic who doesn't know what they are really looking for wouldn't understand what the PS would be for anyway, so why bother

Of course, then I look at something like the MXL 960, and wonder how they can make that thing so cheap. Simply a similar design but with much cheaper components in place, I suspect?

 

[Farview]

Recently I have been getting into the analog part of recording, and I love a good analog sound (Pink Floyd...).
So, if I was looking for an "analog" or "tube" sound or whatever you want to call it.

All mics and all mic preamps are analog. Solid state is still analog.

That's what most of us are trying to say. What you are looking for doesn't necessarily come from a tube, or have to have a tube in the signal path.

A U87 (solid state) into a Neve 1076 (solid state) is a warm, analog type sound. It will sound 'better' and more 'warm' and 'analog' than a MXL tube mic through an ART tube MP.

You're looking in the wrong place for the sound you want. I would also be willing to bet that you are really looking for the feel of those old albums and not really the sound of them.

The vocals on some Beatles songs are really distorted and muffled if you listen to them. If I did that to one of my clients, they would want it re-recorded for free. It's not that the sound of the records were that great (by todays recording standards), it's just that the combination of the song and the textures that they got gelled together to create something larger than the sum of it's parts.