Yeah 75 amps would be a nasty load on even a high output charging system because as long as the radio was on and amp powered up the full draw of current would be there. That is the downside of class A amps they are always running full throttle from power up to shut down. Again, they also generate tremendous heat as well and hate being overdriven. However, if you get everything set perfectly they are nice sounding amps. I just feel that the extra power consumption is not feasible in a 12v car setup (and apparently so does Butler since they only use tubes in the preamp).

 

You're correct, tubes do consume more power, primarily because of the need to heat their filaments. However, I don't consider the consumption excessive, nor do thousands of other tube afficianados. Incidentally, I'm not selling anything, and I don't really want to get into a "tube vs. solid-state" discussion. It's been done to death on many more appropriate forums. I was really only interested in whether anyone here had installed one for mobile use. A special power supply is required, and I'd like to hear about experiences with this.

Regarding longevity, yes, tubes wear out eventually. However, most are rated at thousands of hours of use, and when they finally go, it's a simple matter to plug in a replacement.

I'll conclude by noting that the comments above regarding heat and distortion are simply wrong. Vacuum tubes are always hot, that's how they work, and distortion levels are very low in properly designed amps. Incidentally, I've also designed circuitry with solid state devices from audio to well above 20 gHz. I'm intimately familiar with both technologies.

Happy listening!!

 

I personally believe it's great to have someone posting here with something more than "hearsay" knowledge. Glad to read your posts thus far. Keep it up.

 

The below clip is taken from an expansive write up at:

http://www.guitaramplifierblueprinti...lection330.pdf

"Tubes do not have the “on-off” aspect. They are always conducting and flowing the electron flow. This is one of their differences. This is
not better or worse, it is different. Before you think or buy the fact that sticking a tube in the front end of a digital or solid state amp is
going to turn it into a tube amp, think again. It may give you everything you are looking for, and that may be just what you wanted, tube or
no tube." (Part 1, pg. 4)

This is noted because the Butler amp uses this type setup. However, that review has great information and is very lengthy if you want to review it.

Now speaking factually, I have personally heard many Butler Tube Drivers and yes it is a nice sounding amp. Would it be my choice? No. I prefer the McIntosh amp and esoteric amps over the Butler Tube Driver for a variety of reasons, none of which having to do with sonic impression (because quite frankly in a double blind test I can promise you not one person could tell the difference between the three).

If you feel that you can hear a difference between a tube and a solid state then you should take Richard Clarks $10,000.00 amp challenge cause he is saying you can't and has proven many golden ears wrong.

Anyway, not trying to slam tubes, just saying that they are different and IMO not practical for car audio (that goes for any true class A amps not just tubes) because of power demands. It actually is the main reason that most people believe so heavily in tube amps because unlike others they are always in an on state.

 

I don't have time to read the entire article right now, but the sentences you've quoted are incorrect and probably (I assume) out of context. By technical definition, devices operated in class AB1 push-pull do not conduct all the time. The author is appears to be describing class A, but that has never been mainstream for high-power amplifiers. Nearly all high-power amps are AB1 push-pull, and that includes both tube and solid state. No, tube amplifiers won't equal solid state for efficiency, but we're not talking orders of magnitude difference.

 

I had written a lenghty reply and it came out as curt no matter how I worded it. That is not my intention but I do want to say this much if the amp is a tube hybrid then it is nothing more than a solid state amp with both even and odd order harmonics present. If the amp is a pure tube it only has even order harmonics. If the amp is pure solid state it only has odd order harmonics. Even order are much more bearable to listen to but the odd orders present in your higher quality AB amps is so minimal that you can't detect it at all unless driven well below it's intended impedance.

This is all really a moot point with class discussion but I assure you a true tube amp is Class A, uses more power and generates more heat as a result of it's inefficient operation for the full 360 degrees of the power cycle. The only thing that you could possibly say for most tube amps that make them remotely like an AB is that some modulate current to reduce power consumption.

Here is a link that explains the differences and offers schematics of each as well as some charts. It may be useful for those interested in knowing more.

http://sound.westhost.com/class-a.htm

 

Are you actually suggesting that there is no such thing as an Class AB all tube amp?

 

I am not saying you cannot build a tube amp as class AB. There are class A tube amps there are class AB tube amps and there are Class A that act similar to AB but are still class A but are merely power modulated.

What I am stressing is that if a tube is used in anything other than class A it will add both even and odd order THD and therefore the discussion becomes a moot point. That is of course unless you like adding the even order THD to your music. In that case rock on. If your like me where I want the cleanest possible amp available, then you will not find a tube amp that will have distortion levels lower than best solid-state amps. Again, even order and odd order is what I stress and only meant to briefly touch on amplifier class to make a point since most true audiophiles will use a bi-amp setup using both class A for tweeters and AB for the low mid to sub. Apparently more was read into the statement than I intended. I tend to be guilty of this at times having a bad habit of not making my point totally clear until pushed.

You see where I am coming from yet? Let me try once more. These are the points I have been trying to make.

Tubes:
Power hungry
Create more distortion (be it even order)
Generate tons of heat
In AB setup create both even and odd order harmonics
Can be volatile to vibration
Are old technology
Are more expensive
Have a cult following
Are over-priced for what they are
Have a shorter life expectancy
Are over marketed for something they are not

Solid-state

More efficient
Generate less heat
Take up less space
Longer life expectancy
Less distortion than tubes
More stable to voltage fluctuation
More affordable for high quality

Is that better?

 

That's incorrect. A push-pull tube amplifier stage cancels even-order harmonics at the output transformer. It outputs odd-order only. OTOH, a single-ended class A output stage will generally produce mostly even-order energy, with odd-order content to a lesser degree. So, the harmonic energy is determined not so much by the type of amplifying device (tube or transistor), but rather by the circuit configuration.

I can't imagine where you heard that. I have approximately 12 tube amplifiers in my house at this time. Of those, nine are commercially manufactured class AB. You can believe me when I tell you they are not merely "like" AB. In fact, class AB tube amplifiers were invented years before the transistor. If I remember correctly, the patents fall in the late '20s or early '30s. Again, this has nothing to do with the amplifying device, only with its application to the task. Solid state amps are also designed for both class A and AB (and other classes as well).

I know you posted a link, but the article references class A amplifiers only. For a much broader spectrum of vacuum tube tutorials, check the link below. These were written by the masters of their day:

http://www.audioxpress.com/resource/...lass/index.htm

Also, just for a taste of all the tube audio resources on the Web, here's one link that will get you started:

http://www.worldtubeaudio.com/directory/directory.htm

I'm still hoping someone with a tube amp in their vehicle will chime in. After all, trucks are especially well suited for this. Considering their relatively enormous GVW, what's another three-hundred pounds of tubes and transformers?

Happy listening!

 

My comments are in curly brackets:

Happy listening!!

 

Come on, Chris. Your lack of knowledge of this "old technology" is showing through to us "cult" members. Give it up. Anyone with knowledge of tube technology is not impressed.

 

Can you tell an audible difference from a tube amp and a solid state?

If you say no. Then why would you want to possibly use a tube being that it is so obvious they cost more for the same quality and sound no better?

If it is merely because you like the look or nostalgia from a tube then that is great.

All test results I have ever seen comparing an equally priced tube to a likewise equally priced solid state for clean signal reproduction has proven that the solid state amp reproduces sound cleaner, with less power consumption, and more true power output available.

So I guess I am just wondering why again you want to use a tube amp?

My reason for using them in the past was just to see if I could build one and to see for myself what all the fuss was about. I was not impressed. My Carver cubes sounded just as good as any tube I have ever heard and so did my Hafler 500s. My other amps cost way less that the Audio Art tube my friend just insisted I compare them to.

 

There are numerous online forums (such as http://www.audioasylum.com) where that question could be better discussed.

FWIW, I'm reasonably familiar with Bob Carver's designs and Hafler, too. I was heavily involved in audio througout that entire period, starting when Hafler was selling his tube work through Dynaco. I also remember when Bob Carver's wife left him, took the company (Phase Linear) with her, and sold it to Pioneer. Carver later invented an ingenious multipath distortion elimination scheme for FM stereo reception that was integrated into several of his tuners and receivers. The Cube, OTOH, was not his best work, and a great many failed ("blew up") shortly after leaving dealer's shelves. Hafler's MOSFET stuff does sound very good, but only because it comes the nearest to equalling his earlier tube work.

I'm sorry to hear you didn't have a better experience when you auditioned the tube equipment. It really requires something of an investment in the entire system to extract the benefits. When you get it right, Sheryl Crowe will whisper in your ear and Green Day will be in your face.

Happy Listening!

 

I've been in discussions with you before, Chris, and I know that this is headed nowhere. You are obviously very knowledgeable about audio, and if you do not hear an audible difference between tube amps and solid state, then by all means you should not spend the extra $$ to have one.

 

Chris -

I agree with most of what you have said, especially about the listening tests.

Julian Hirsch once set up an A-B-X switch box to allow blind testing of amps. Guess what he found:

If the amp is properly designed and operated within it's design parameters, humans could not successfully identify which amp was playing at the time.

That really pissed off the audiophile community, but the facts were right there for everyone to review. If I remember correctly, he invited several recognized "golden ears" to take the test and they too were unable to score higher than 50% accuracy on identifying the playing amplifier.

Remember Bob Carver's M 1.0t amp ? He modified it to sound identical to a Conrad-Johnson tube amp costing 12 times as much. Guess what - he had to ADD distortion to the low end so that it would sound like the CJ. Of course, the 1.0t had WAY more power and was priced in the $500 range. Reliable ? I bought mine in 1988 and it still works perfectly today. It has withstood thousands of hours of use at high output levels, into planar speakers (demanding load), and it still works flawlessly.

So, I guess I am saying (not to you, Chris): If you like tube equipment, buy it and enjoy it. Don't insult everyone's intelligence by suggesting that solid state audio gear hasn't eclipsed tube gear performance. Lest everyone forget, the object is to ACCURATELY reproduce and then amplify the original recording - nothing more, nothing less. While adding a "warm" tonal flavoring to the music (the usual description given to the sound of tube amps) may be something you enjoy, that does not indicate that the tube amp is superior.

Now, who wants to argue about LP's vs. CD's ???