jubilee

[Guest " "]

....there are tube PCB's that can be used such as the attached which will accept an XLR or RCA input and drive an XLR output in a pure balanced mode using a dedicated tube triode for each phase of the XLR signal.

 

 

You guys have FAR too much time on your hands if this much effort is being used to figure out how to convert from unbalanced to balanced! 

....especially when you consider that the opamp option is presented for the purpose of adjustable level matching and is not required to simply convert the topologies. 

Bill Whitlock has beaten this proverbial horse to death with all of the information one ever needs.

Geesh, some can manufacture a connundrum out of anything. 

Yeah, I have plenty of time....glad to be able to contribute...btw...that PCB is 25 bucks.

[ClaudeJ1]

I checked and they are indeed B&C KPT904's.

I have no idea how they compare to K-69's, but I can tell you this: They sound DARN GOOD!

Bob

Trey told me they were better drivers.

[DrWho]

DrWho--

Yes, of course anyone can buy anything and roll their own solution - external boxes, or whatever they like. No worries.

I certainly don't agree however regarding "pitfalls" of frequency response. Great transformers have superb FR. They will go both lower and higher than any horn system I have ever encountered. I think the best sound possible is the Peach in HiZ mode with an audio grade amplifier. But, for those who are dedicated to using klub amps, and yet like the sound of the Peach, the transformer modded Peach will still outperform all the garbage kludgeboxes being used now, and for anyone who values the audiophile listening aesthetic, I think they'll find it is very, very little sacrifice from the regular Peach.

As for OpAmps, well of course, anyone, yourself included, should feel free to whip up any OpAmp creation you enjoy or prefer!

I think you might have misconstrued my point, which was that bad transformers exhibit rolloffs within the audible passband. There are all sorts of cheaper transformers that achieve the proper winding ratios, but will sound like crap. Distortion is another issue (again, with the cheaper alternatives).

Btw, have you listened to these "klub amps"? And are you referring to the ART Cleanbox or active crossovers as "kludgeboxes"? I guess the main reason I ask is because I think you would be surprised if you gave them an honest criticism. I'm not saying that I don't find any fault with them, but I think it's safe to say that those that have heard them would agree that the benefits far outweigh the compromises.

[DrWho]

Bill Whitlock has beaten this proverbial horse to death with all of the information one ever needs.

http://www.jensen-transformers.com/an/an003.pdf

[Deang]

I'm have one of these on the way. No transformer(s). They say that's good -- I guess I'll find out.

http://www.aphex.com/124A.htm

[bodcaw boy]

audiophile........Audiophiles are simply people who apply their perception and attendant discrimination to sound..........i have SOOOOOO been looking for a definition.....i guess i better throw my gear away.

in Christ, because of God's grace,

roy

[jacksonbart]

As opposed to "klub amps", how about we call them; "sound buckets" or "screw top audio".

[DrWho]

Either I have to learn to read better or you have to learn to write better, huh?

Probably the latter.... []

Klub amps are made to a good purpose - reliable, rugged,
high powered and cheap. Not an easy thing to accomplish. For 99% of the
population, nothing more is needed. They make all the sound anyone can
consume and more. Buckets and buckets of sound! But, just like the guy
who wants to resolve that really feint double star out there, there are
people who want to resolve every last layer of sound, every last
detail of the musical fabric and for that, they need a very different
kind of amp. Just as the optician CAREFULLY chooses glass and coatings
and so forth, the engineer can choose parts and topologies that
increase resolving power, increase clarity and so on. And, unfortuntely
just like the $5,000 refractor 'scope, these amps cost more because
more went into the design, building and parts than a basic klub
amp.

You forget one other aspect of "klub amps"...which
is that the majority of users of said amps are making their living
based on how
good the sound is. In other words, tonal accuracy is an absolute high
priority in these amps. And to use your analogy, I might also argue
that the increase in resolving power of the refraction telescopes comes
from an increase in efficiency....it pops up all the time in the world
in all aspects of life. Increased efficiency improves performance.

I am not
sure why people are so stubborn to recognize that aural perception is
VARIABLE among people, just as visual perception is variable, or taste
perception.

That notion implies the concept of "golden
ears" which I've become to believe is usually just a fabrication of
one's own arrogance rather than an actual ability to hear. I have found
it easy to provide all sorts of comparisons for "golden ears" where
they can never prove that they can hear the differences they claim. Some
argue it's a deficiency of the testing situation to which I would reply
that it is then the responsibility of the "golden ears" to find tests that
will validate their claims. Until then, I'll just rely on the huge
amounts of research validating true levels of human perception (which
I'm still learning more about everyday - don't wanna imply that I'm an
expert in that field...just that there are already experts doing the
work).

Along the same lines, I would question why some people are
resistant to the notion that what they enjoy may not be an accurate
reproduction of the original signal. I could care less if someone
prefers the sound of some kind of distortion, but to claim it as
accurate is where I have issues...or rather, it's annoying when
accurate reproduction is dissed. Everyone that has made the move to
Klipsch has no doubt experienced an increase in the number of bad
recordings sounding untolerable - the concept is mentioned all the time
on the forum, "a more accurate system is more revealing so it needs
better source material". Why is it ok to get rid of some of the bad
recordings, but not all of them? I understand that everyone has
different constraints limiting the amount of fidelity they can achieve,
but the thing that kills me is that so many people are very resistant
to the notion that better sound could be achieved. The instant anyone
mentions the notion that people can improve their systems, they get all
defensive - almost arguing that what they have could never be
surpassed. These notions especially come up all the time in Jubilee
threads - though I can't imagine why.... [*-)]

Let me be clear - - the sound of pro gear to my ears is like a steady diet of junk food.

Not
to be annoying, but I don't see how one could make that claim without
having listened to every piece of pro gear. What specific pro gear have
you heard? Better yet, have you listened to any of the gear being
mentioned in this thread? My guess is no, because you have already
established your biases many years ago. For what it's worth, modern
amps don't sound like anything from the 70's or 80's.

Another thing I very much dislike about audio is the quick
reaction to over generalize and attribute perceptions to the wrong
variables...and then justify it as some kind of higher level of
refinement.

I guess from your point of view
anyone going to cooking school or chef school is wasting their effort?
Anyone choosing a $150 gourmet meal when they could have had a Double
Bacon with Extra Cheese is wasting $148.

Using
your analogy, my argument would be drawing attention to the fact
that modern cooking schools use chemistry to enhance the flavor. I
would also argue that a modern cutting edge kitchen is going to
produce food that tastes much better than anything you would ever find
100 years ago. What I don't believe is that no progress has ever been
made
in any field of engineering. I would also argue that cost has
absolutely no relevance to science (a discussion of performance). Cost
is only affected by engineering, but like you point out, cost doesn't
matter for the highest levels of refinement.

[jacksonbart]

"sound bucket" works for me!

so you're more into tubers?

[bodcaw boy]

Roy,

Well, since you are an employee of the generous company hosting this discussion, I guess we ought to let you have the last and final word now shouldn't we?

wow deneen! that is so unelitist of you!! but even so, i would take mine as i like mine better......[8-|]

in Christ, because of God's grace,

roy

[bodcaw boy]

"That notion implies the concept of "golden ears" which I've become to believe is usually just a fabrication of one's own arrogance rather than an actual ability to hear. "

Awwww, you're red hot doc!

in Christ, because of God's grace,

roy

[Audio Flynn]

Doc,

Your Assertion #1: "You forget one other aspect of "klub amps"...which is that the majority of users of said amps are making their living based on how good the sound is. In other words, tonal accuracy is an absolute high priority in these amps."

Your Assertion #2: "That notion implies the concept of "golden ears" which I've become to believe is usually just a fabrication of one's own arrogance rather than an actual ability to hear. I have found it easy to provide all sorts of comparisons for "golden ears" where they can never prove that they can hear the differences they claim."
------------------------
Now then, that's a good example there of self-contradiction, right? First you assert that some people making their living with amps CAN and DO determine which ones sound "tonally accurate." But then not 30-seconds later you offer #2 which says that all such claims are arrogant fabrications! Which is it Doc?

What is "tonal accuracy" if not something which is heard and perceived? "Good" is subjective, isn't it? Why do stagehands and roadies have this ability to hear, but others are arrogant fabricators? ($12 word for "liar.")

You're very funny today! But, c'mon Doc, you can do better than that. You're a young whippersnapper at University, and I am an old fart with an addled brain, and yet even I could perceive the contradiction in that Whopper®.

I am not sure why people are so stubborn to recognize that aural
perception is VARIABLE among people, just as visual perception is
variable, or taste perception. Remember -- most people who are
so-called "stereo-nuts" or "audio enthusiasts" are not audiophiles,
they are just people who love to have and play stereo gear. Great! It's
fun! Just as most people who eat are not gourmets, right? They just
enjoy eating. Nothing at all wrong with that.

======================

Two great anologies Mark and associated long post!

Another that comes to mind is fine firearms. Any old 12 ga. Mossberg pump shotgun will put game on the table but the pursuit of fine shooting with a High grade Browning Citori for example is a totally different feel.

Granted my expereince with Klub amps and basic SS preamps is 10-20 years old and needs to be refreshed. I will pick up something like a Klub amp or a chip amp for the summer months in 2008 when tube heat will make my room uncomfortable some days, but my audiophile memory coupled with common sense convnces me it will be a big fall off rom my recntly upgraded 2 channel configuration.

VIVA Belles , VRD and BLueberry! [8-|]

[jon_010101]

You forget one other aspect of "klub amps"...which

is that the majority of users of said amps are making their living

based on how

good the sound is. In other words, tonal accuracy is an absolute high

priority in these amps. And to use your analogy, I might also argue

that the increase in resolving power of the refraction telescopes comes

from an increase in efficiency....it pops up all the time in the world

in all aspects of life. Increased efficiency improves performance.

DrWho, the appeal of klub amps lies in their efficiency, and their ability to produce relatively undistorted sound while pushing 100 Watts of power all day long. However, in an audio context, especially in a high efficiency system, they are simply too blunt of an object. When you have a bunch of class B stages running at LOW power, the amplifier becomes completely crippled by crossover distortion, and will actually exhibit greater distortion than a fine tube amp. Many push pull class A tube amps will have about 6dB less distortion than a typical class B solid state amp when measured at 1 Watt output power. And, that tube distortion is going to be primarily low-order -- 2nd, 3rd, and 4th harmonics. Nothing too awful. The klub amp will be producing far more "nasty" distortion, almost like a correlated noise signal riding on top of your music. Hence that grayed-out, crunchy, dry sound of a solid state amp at low power. Imagine using photoshop and trying to "sharpen" an image until the edges are pixelated. There's actually a loss of information. Certainly this can be avoided -- as engineers have know for a long time -- by using class A amplification stages for small signals with wide dynamic range. This isn't some conspiracy of audiophiles against pro audio guys. But each truly has a unique set of needs, which engineers know how to address, and which both groups need to understand. I love the sound of a good pro rig -- but take that system out of its element, and idle it along at 1W output, and the results will just not be as satisfying.

By the way, this also applies to preamps with op-amp stages. Take a look at op-amp data sheets and see how the distortion looks at 0.1Vrms output compared to 5Vrms output. If you are driving an amp, and need a low voltage signal (often <<.1Vrms), a tube gain stage can be a better source. That said, I have no problem with op-amps for gain stages, or output stages of line-level devices -- tuners, CD players, and phono preamps, where they can actually work a bit. But they, again, become a blunt instrument when driving a hifi power amp with a relatively tiny signal. A tube driving a transformer can be a much more elegant solution if one is willing to pay for it. This is the same reason why good tube or discrete FET microphones sound so much better than an op-amp mic. Efficiency rarely comes without sacrifice, and without added (avoidable) complexity.

JMHO.

BTW, Mark deserves a prize for his telescope analogy! I don't post much on this forum, but this thread was too interesting to avoid.

[bodcaw boy]

i would LOOOOOOOOVE to see your data.

in Christ, because of God's grace,

roy

[PrestonTom]

Well, Dr Who, I hope you have learned your lesson.

You have attacked deeply held religious convictions and have insulted many in the process. This is not about accurately reproducing a recording. It is about making things sound good. You can measure accuracy all you want, but you will be missing the point. You need to get at the issue of what sounds good. In other denominations we sometimes use the words - "musical", "lush", "harmonically rich" and "sweet". Are you going to insult them also?

Get with the program (you young whipper snapper). Those books are making your brain go soft.

Good Luck,

-Reverend Tom

[jon_010101]

i would LOOOOOOOOVE to see your data.

"Distortion in Power Ampfliers" by Douglas Self (on google) has some great examples of class B distortion. Not all "klub" amps are a trainwreck, but very few are optimized for lower power use, in contrast with a class A tube circuit (or even an audiophile solid state circuit -- or something designed for monitoring / mastering vs. concerts). BTW, Self's work for Cambridge on the 840A is worthy of much respect -- a clever method to transition between class A at low powers and class B for higher power, while avoiding AB operation. Even magazine measurements from stereophile or soundstage.com often show signs of various forms of crossover distortion -- and many tube amps (class A push-pull especially) will out-measure the sand-amp competition at the crucial territory around 1W output.

Any engineers feel free to correct or disagree with me here, though -- I'm a EE, but circuits are truly not my expertise.

[PrestonTom]

"This is not about accurately reproducing a recording. It is about making things sound good. You can measure accuracy all you want, but you will be missing the point."

=======

Tom,

Ok, we have a listening room with two amps and a CD player. I have a stack of old Rolling Stones CDs here. Tell me how you will determine OBJECTIVELY which amp is more accurate at reproducing what was recorded by the Stones. Bring all the instruments you would like to use - - assume they are free!

Hmmm, I suspect the engineers at Crown, were not using Rolling Stones CDs as their test signal. Perhaps that was their problem.

Good Luck,

-Tom

[sfogg]

Mark,

"Ok, we have a listening room with two amps and a CD player. I have a
stack of old Rolling Stones CDs here. Tell me how you will determine
OBJECTIVELY which amp is more accurate at reproducing what was recorded
by the Stones. Bring all the instruments you would like to use - -
assume they are free!"

That is easier then you think. Two channel FFT with a transfer function between the channels would do it. One channel of the FFT measures the input to the amp and the other channel measures the output of the amp. Have the amp feeding a real speaker (not a resistor).

The transfer function will show you the difference between input and output (both in FR and phase) and it will do that no matter what signal you feed it... including the Rolling Stones CDs. The greater the difference between input and output the less accurate the amp is to the source.

What is the output impedance of your pCats? Do you really think those are going to show less difference between input/output compared to a low output impedance SS amplifier when connected to a real load with varying impedance.

Anyone have a pCat near me? I'd be glad to run this test on one and show the results compared to the K2 you referenced above.

Too many audiophiles assume what they like must therefor be 'accurate.' Maybe it is, maybe it isn't... don't worry about it. If you like it that is what matters.

Shawn

[sfogg]

Mark,

"I don't know any audiophiles who believe that. I think they say, "God, Amp A sounds awful. I just want to turn it off. Amp A sounds really fabulous. I can't wait to listen to more music tonight." As best I can tell, it is everyone else talking about "accuracy.""

Are you serious?

Have you ever actually read any tubes vs. SS debate? Or vinyl vs. CD? PP vs. SET?

The debates are all based on the premise of 'accuracy' in one flavor or another. Look at Jon's post above. He is claiming the 'klub' amps have more distortion then tubes. More distortion is less accuracy. Your site talks about tubes being more 'linear' then SS...etc...etc.

Output impedance of the pCats?

Shawn

[jon_010101]

The transfer function will show you the difference between input and output (both in FR and phase) and it will do that no matter what signal you feed it... including the Rolling Stones CDs. The greater the difference between input and output the less accurate the amp is to the source.

 

What is the output impedance of your pCats?  Do you really think those are going to show less difference between input/output compared to a low output impedance SS amplifier when connected to a real load with varying impedance.

This reminds me of an interesting experiment I saw posted on diyaudio.com. A fellow first connected a solid state amp, then a single ended triode amp, to a speaker and measured harmonic distortion, comparing distortion levels at the amps' outputs and the distortion in the room. The single ended amp's distortion measured much higher at the output, but somewhat lower in the room, due to cancellation with the speaker's distortion. This result basically blew my mind, but it makes physical sense (and also demonstrates how high speaker distortion can be compared to amp distortion). Be sure to check out part 2, linked at the bottom... it gets even more interesting.

link

Of course, this is only a consideration of harmonic distortion, not frequency response, or resolution of transients or anything else, but I do get the impression that many audiophiles value low distortion (and non-objectionable vs. objectionable distortion) over ruler-flat response. Personally, I like having low distortion, high resolution, and natural response whenever possible, but distortion is in my opinion the worse of these evils ;-)