Tube Pre-amp (1 Viewer)

[Lee Scoggins]

what would be the premise for going with Tubes

The answer is a more accurate midrange and high frequency band. I got into tubes after having some ultra-expensive solid state gear because I work part-time on recording studio and live events and I was dissatisfied with the midrange portrayal by SS amps. I'm not the only one who feels this way either. David Chesky mostly uses tubes in his playback system and mastering suite and Bob Katz will generally only work with tube-based mic preamps.

In the past, the theory was that the "euphonic" nature of tubes and even order distortion was more pleasing but Conrad Johnson and Audio Research created new circuit topologies that moved away from euphonic, which by definition is not really accurate, to a neutral realistic sound. In fact, many of us believe that the midrange, arguably the most important area of the FR curve, is only really done right by tubes. But this is a debate like that between fine vinyl and fine digital - at any given moment you will find half the audiophiles and engineers on any given side.

The reason I stepped in is that I believe this "even order" discussion/myth, while partly true in the past, takes away from the incredible accuracy that firms like C-J, ARC, Lamm, BAT, VTL, Manley and others have achieved. I have a friend that has $9K Pass Labs X series amps. They sound wonderful but I still feel there is something missing in the midrange versus tubes, for instance.

Tubes do have to be replaced and biased so they are a bit more fussy but I feel it is worth it because they sound so right when I compare my studio tapes to that day's actual performance.

 

[Chu Gai]

well we musn't forget all the ways euphonics creep in there now like high output impedances that can exist on the amp end such that the output of the amp follows the countours of the impedance curves of the speakers. that essentially takes the effect of sticking in an equalizer into the musical path and shaping the countour of the sound.
learning to build or assemble an amp doesn't really teach you much other than learning how to put things together and solder. kind of like learning how to sweat copper pipe neatly or paint by numbers. if you're going to want to learn then you'll need to spend some time studying electronics, circuits, electrical theory, etc.
SET's or Single Ended Triodes, while relatively inexpensive to build, still cost a couple of hundred plus your time. The end result is that you get probably the worst type of tube amp there is: barely able to generate the power of a 10 watt light bulb, audible distortion, an enormous output impedance, inaccurate, colored, hum prone, etc. OTOH you now have the 'pride' of having made a poorly performing piece of junk with the knowledge that you'd never accept such crap performance from solid state.
However as always, it's your gun, your bullet, your foot

 

[Brett DiMichele]

LOL Chu

Tell me how you really feel? SETi rules!

 

[Scott_N]

Well Chu when I heard a pair of Cary CAD-805's they sure didn't sound like the worst amps i've ever heard. The CAD-300SE and the CAD-2A3SE both sound alot bigger than their rated power too.

 

[Chu Gai]

Well Scott, I'm not saying you can't have a preference for them or for the effects that they have on the signal fed to them. frequency shaping of the resulting audio spectrum by a high impedance output of SET is not likely something that's going to be talked about by the people putting these units out. Any idea what the value was for the CARY unit?

But really what do you actually learn from soldering and connecting a few pieces together?

Brett...how do I like tubes? They're fine, they're quaint, nostalgic, and they make even crappy recordings sound good. Accurate though, they're not.

 

[Scott_N]

They retail for $8995 a pair. I'm not a SET fan I like push-pull tube amps but I don't think it's fair to make a blanket statement about SET amps if all you have heard is cheap SET amps. The nice thing about this hobby is there are many choices.

 

[Chu Gai]

So an expensive SET amp gives you what? 40 watts of speaker dependant output shaping?
Understand Scott, I'm not arguing against one's preference. My comments have to do with issues of accuracy and fidelity.
How's about a separate thread? The site's gotten a little stale and controversy is good to get things hopping!

 

[Michael R Price]

Chu,

Tubes aren't that bad. Modern good quality tube amps with a decent amount of feedback, especially the push-pull ones, don't have such gross distortion. Just ask Brett, the AV20s have something like 0.2% at 1 watt? I think Cary was just a company that intentionally ignores the measured quality (and I probably wouldn't like the sound of 3% THD, either). Then there's the issue of solid state amps having distortions not revealed by THD measurements. I have a typical good amp with 0.005% distortion or something, yet the Class A Zen (sharing some of the tube deficiencies) still sounds better in ways.

 

[Jonathan T]

Guys, as far as music goes, I'm looking for a warm, full sound. Something that mimiks the broad sound you get when at a live performance. And I'm less conserened with accuracy. Also, I'm not out to learn about electricial theory by building an amp. I can solder, but I've never built an amp before. That was the learning curve I was refering too. As long as there are instructions, I feel I will be able to build the amp.

If a tube amp can give me this, then I'd be very intrested.

 

[Jonathan T]

Guys, I checkout DIY HIFI Supply, and I found this:
http://www.diyhifisupply.com/diy_kits/the_ella.html

What do you think of it? $500, but it's in Hong Kong and shipping s $++++. My father would never let me use his credit card to order that. Anyone else got another place that is similar to it but is in the US?

 

[Scott Oliver]

Um that is the amp I talked about above.

Do you they really make you pay for shipping from Hong Kong?
I know the manufacturer is China based but I thought DIY HiFi Supply was a US based importer and hence would already have those shipping costs covoered and built into the price. Interesting.

Anyhow, there is pretty good word of mouth on Audio Asylum about these kits, althought the majority of the talk is about the Billie but they are more of an SET crowd over there.

 

[Chu Gai]

What do you think of using your existing setup Jonathan and spending only a few dollars to get your SS setup to behave like a tube amp?
Or what about inserting a Behringer Ultra-Q into the signal path. That's got tubes and a couple of Parametric Equalizers. Far as I can tell, it's strictly analog for those fearful of digital. Basically you can 'dial in' the amount of tube effect you want. US cost somewhere in the mid 100's. Towards the lower end of that if you go and haggle in person. You can find them at your local pro audio shop.

 

[Jonathan T]

Scott, I realized that was the amp you were talking about after I posted it, while I was in the shower, oops.

As for shipping, they say that all items are shipped from Hong Kong, so I can't get a kit unless I can buy it from a US distirbutor.

 

[LanceJ]

If anybody has the issue of Sound & Vision from last year where a band (Phish I think) was asked to compare a tube system to a solid state system, read it because that article has some very revealing results of that comparison.

Quickie summary (this is from memory so little details might be missing):

The tube system made everything sound good. Bass was lacking though. Various metaphyscial adjectives were used to describe the sound.

The solid state system had a varying sound quality: some CD's sounded excellent, some good & some just O.K. Bass was powerful & controlled.

Fact: Every recording is made with different equipment, different people and different quality goals. And as the band members themselves commented, it was to be expected that each CD would have a different sound to it.

I personally don't want equipment that coats my music with "happy waves"; this way I will hear exactly what the ARTIST wants me to hear.

LJ

 

[Brett DiMichele]

Lance,

The only flaw in that theory is that the "Artist" has little
to do with what the actual product sounds like, the little
task falls in the hands of the people who Master the recordings.

So how do you know you are hearing "exactly" what the actual
"artist" intended? Many times the recording studio will tell
the artist "do this" "try this" "Lets try it like this" yadda
yadda yadda..

It all comes down to what you want to hear. If I want
happy waves I will fire up my tubes. If I want it to sound
the way it comes off the CD I will use S.S.

It's just one of those preference things I guess.

 

[Chu Gai]

and if you want justice, you'll invite the people who mixed the recording over while they stand barefoot on a wet carpet and toss them a high current source

 

[Scott_N]

Chu

What kind of accuracy? To the recording be it good or bad? Or in making you believe that you are hearing live music. I prefer to think of myself as a music lover rather than an audiophile. To me if a recording is shrill and dry and you have to clean out your ears after a few minutes that's like watching a movie for the explosions intstead of a good plot. I'll take good vinyl over good CD and i'll take good tubes over good SS.

 

[Kevin_R_H]

Scott,

You're treading down a slippery slope...

I thought of responding to Chu's previous post, but I know there is nothing I could possibly write that could change his mind. He seems to be a bright guy, and long ago I accepted that bright people are going to disagree sometimes.

I stopped trying to win arguments in High School.

Kevin

 

[Kevin_R_H]

Lance,

I will respond to your "Phish" post.

When an article states that they listened to "a tube system", and that "it" made everything sound the same, and that "it" was lacking in bass, you cannot extrapolate from that experience.

Let's say that Mario Andretti test-drove a tiny 4-door sedan, and stated he was cramped. I shouldn't extrapolate from that statement that all 4-door sedans are cramped for space, and that if you want a roomy car, buy a coupe.

There are scores of different tube manufacturers, and just as there is a difference in sound from a poorly designed cheapie receiver to a $25,000 pair of Levinson monoblocks, the same holds true for tube amps.

For example, let's talk about the generalization that tubes deliver wimpy bass. I own speakers that are considered a "difficult load". The designer states that if you want to utilize a tube power amp, you are strongly encouraged to biamp. Most follow his advice, but I don't. I run them full-range with tubes.

Despite this (and the fact my system is located on the 2nd floor of my house), I can absolutely rattle the windows and shake the floor using regular redbook CDs.

In addition, on 3 occasions, I have had friends bring over pretty nice SS amps for comparos. One was the Classe' 300W stereo block. Another was a 250W McIntosh stereo block. And the third (the best of the group) was a 100W Pure Class A behemoth called the Audire Parlando.

I'm not going to wax poetic on my opinions of all the pros and cons (as to not offend any tube-phobe reading this), but the quantity and quality of bass is pretty easy to discern. Let's just say that no listener felt my tubes were lacking in the bass department (relative to their amps).

In audio, generalizations are risky. But generalizations from one example is ludicrous.

P.S. This is not to mention that the members of Phish probably lost a decent portion of their hearing long ago...

Kevin

 

[Brett DiMichele]

Kevin,

I will say one thing.. There aren't many affordable tubes
that will drive a good pair of full range mains with good
dampening over the large low frequency drivers. Yeah that
is certainly a blanket statement and it's also the truth.

"Affordable" I guess is the key word though. To one guy
15K for good tube amps may be completely affordable.

I don't think that a 1K tube amp would do it though.. I
would love to see one that would drive my 10's as cleanly
as Bob Carver can (For the price).

But yep there certainly are tubes that can drive full range
and produce loads of prodigious bass.