[capwkidd]

I have been doing some searching regarding tube info, finding allot, but it's pretty drawn out, I guess I am looking for cliff notes.

Anyone have a short wiki on tubes?

I was at RMAF last year, and I spoke with a rep from one company who was giving me all this info about the general sound of the various model tubes, which I do not really remember any more. I do know some things, kind of a swiss cheese knowledge. I am just looking for short explanations of things, like, the sound of certain model tubes (in general).

I am tube curious.... so a tube amp in probably in my not too distant future, but the big question is, what to get?

One thing I know, I love a strong, tight bottom end, that is why I primarily use a digital amp, and even though the one I have is said to have a "tube like" mid/highs, I am looking for something better.

I know about damping factor, and it appears tubes lack in that area, but that can't be the case for all tube amps.

Looks like the primary choice in tube amps is SET, because they have less distortion (so I understand), but what is the advantage of tube amps that can switch between triode and ultralinear?

I hear some tube amps do not have any feedback at all, and are pure class A .... who make such amps? All I really know about pure class A amps is that they do not have "cross over distortion", which I am not sure what that really sounds like.... I know one thing, when something does not sound right, it does not sound right.... listening fatigue is definitely an issue...

So, drop some knowledge on me.... Thanks.

[rbwalt]

if you want information on tubes then i recommend http://www.ramlabs-musicreference.com/. as far as SET's go they are big in the mids, truncated in the bass and highs.

r.

[SET Man]

Hey!

     I'm a big tube fan and a SET amps user There is something about tube that reminded me more of the real instruments.

     As for tube. Beside many different type of tubes there are also different designs/topologies of tube amps. Two most common type are Push-Pull/PP and Single Ended Triode/SET.

     The PP type is a way to get the most of power of tube. This involve splitting the signal into two halve and having two tubes, one driving - and one driving + side of the signal. The problem with this is that once you split the signal it is impossible to recombine it back perfectly. But it dose provide more power and better measurement than SET.

     The SET type. Usually use direct heated triode/DHT tube like 300B and etc. This is the first type of amplifier made. One tube driving both - and + signal. It is always on and operate in class A. Very inefficient. But it is the purest form. To get more watts you will need very big tube and very high voltage. Most purist choose to make SET with zero feeback but some can have some feedback for better control..... personally I like zero feedback. Also SET tend to have worst measurement compare to PP but most of the distortion will be 2nd order of which some say less irritated to the human ears. With SET amp and it low watt it is very critical to choose right speaker to go with.... high efficient and easy load to drive would go a long way with SET.

   There are more about tube. Anyway if you are new to this than get ready for info overload. There are tons of stuff about tube. I would say take it easy and try to hear as many tube amps as you can. Also, a little note.... tube amps tend to cost more than SS amp, especially SET amp done right, so be careful if you are going to buy those cheap tube amps that flooded site like eBay.

    I'm not an expert but I'm sure others will also fill in.

    Good luck and Don't get hung over with the technical side of it, just listen and see which sound right to you.

if you want information on tubes then i recommend http://www.ramlabs-musicreference.com/. as far as SET's go they are big in the mids, truncated in the bass and highs.

r.

   Well, that depend on what SET amp you've heard. Not all SET are created equal. I agree that most PP and SS amps have tighter bass. But that is subjective. I find my SET's bass to be tuneful, better texture and have better natural decay than many amp I've heard both SS and PP tube amps. As for the high good SET with good design and quality output transformer can have very extend high that sound more natural than most if not all SS amps. Well at least that is how I feel with my own system.

    Well, it is all a personal preference.

Take care,
Buddy

[roscoeiii]

What speakers are you using?

You'd mentioned damping factor, and I find that speakers not only differ in terms of how much power they need but also in terms of the damping factor of the amp involved. A poor damping factor match can lead to speakers either being overdamped (constrained bass response) or underdamped (bass is a big boomy and not as well controlled). In my amp journey I have had problems with both overdamping and underdamping. Synergy, synergy, synergy.

[sebrof]

Anyone have a short wiki on tubes?

I know about damping factor, and it appears tubes lack in that area, but that can't be the case for all tube amps.

I hear some tube amps do not have any feedback at all, and are pure class A .... who make such amps?
So, drop some knowledge on me.... Thanks.

Actually some good info in Wiki, although not really short.

Damping factor is not "lacking" per say, but almost always lower with tube amps, specifically tube amps with no Global Negative Feedback. Single Ended amps, whether single ended triodes (SET: 300b, 2A3, 45, et al) or single ended pentodes (EL34, KT88, 6550, et al) often have no GNF. So with certain speakers an amp with a high DF would be "lacking" as in not a good match.
As others have mentioned, a SET amp is pretty much the purest amplifier in that it's almost always class A (i.e.: Tubes run with the throttle wide open all the time) and usually low power, but not necessarily the best (I think they are, but that's just me). SET amps are usually the most limiting in that you really need to create the system around them more than other topologies. There are hundreds of ways to make great sound; SET, PP tubes, SS, in all sorts of configurations. It depends a lot on the speakers and the rest of the system.

[bunnyma357]

I'm not particularly technical minded, and I found this guide to have a lot of good info, if you can get around the "cookbook" writing style.

www.anthemav.com/downloads/anthem/misc/a-taste-of-tubes/download


Jim C

[capwkidd]

Primary speakers right now are Zu Essence.... I am looking at getting Tannoy to replace them, so, all very efficient speakers...

What speakers are you using?

You'd mentioned damping factor, and I find that speakers not only differ in terms of how much power they need but also in terms of the damping factor of the amp involved. A poor damping factor match can lead to speakers either being overdamped (constrained bass response) or underdamped (bass is a big boomy and not as well controlled). In my amp journey I have had problems with both overdamping and underdamping. Synergy, synergy, synergy.

[capwkidd]

I see the Cary 805's that where used in a couple of rooms at the Newport show are SET class A, with feedback you can adjust.... I'll listen to theses with the Tannoy's again

Actually some good info in Wiki, although not really short.

Damping factor is not "lacking" per say, but almost always lower with tube amps, specifically tube amps with no Global Negative Feedback. Single Ended amps, whether single ended triodes (SET: 300b, 2A3, 45, et al) or single ended pentodes (EL34, KT88, 6550, et al) often have no GNF. So with certain speakers an amp with a high DF would be "lacking" as in not a good match.
As others have mentioned, a SET amp is pretty much the purest amplifier in that it's almost always class A (i.e.: Tubes run with the throttle wide open all the time) and usually low power, but not necessarily the best (I think they are, but that's just me). SET amps are usually the most limiting in that you really need to create the system around them more than other topologies. There are hundreds of ways to make great sound; SET, PP tubes, SS, in all sorts of configurations. It depends a lot on the speakers and the rest of the system.

[capwkidd]

I should be able to compare Cary 805's to my NuForce 9 SE2's.... that should be interesting.... Tube Vs. Digital.... let the fight begin!


There is a question..... What do any of you think of the Cary 805? I see they have similar stereo integrated as well.... I wonder how they sound in comparison?

Bunnyma357: Thanks! I'll be checking out that link...

[Steve]

I have been doing some searching regarding tube info, finding allot, but it's pretty drawn out, I guess I am looking for cliff notes.

I am just looking for short explanations of things, like, the sound of certain model tubes (in general).

One thing I know, I love a strong, tight bottom end, that is why I primarily use a digital amp, and even though the one I have is said to have a "tube like" mid/highs, I am looking for something better.

I know about damping factor, and it appears tubes lack in that area, but that can't be the case for all tube amps.

Looks like the primary choice in tube amps is SET, because they have less distortion (so I understand), but what is the advantage of tube amps that can switch between triode and ultralinear?

I hear some tube amps do not have any feedback at all, and are pure class A .... who make such amps? All I really know about pure class A amps is that they do not have "cross over distortion", which I am not sure what that really sounds like.... I know one thing, when something does not sound right, it does not sound right.... listening fatigue is definitely an issue...

So, drop some knowledge on me.... Thanks.

Alot depends upon the designer and the design. First though, the maximum damping factor possible is not so high as one might think.

Remember the DC resistance of the voice coil, let alone other resistances, affects the overall damping factor. For an 8 ohm speaker we might be talking 6 ohms DC resistance voice coil and 3 DC ohms for a 4 ohm driver voice coil. So the maximum damping factor for a speaker might be in the order of 1.3333 or so.   

With that being said, if one compares the output stages of a SS output amp and tube amp, one sees the high collector to emitter resistance between B+ filter caps and output, while with a tube output stage one sees only the OPT primary impedance between the B+ filter caps and output. So the isolation between the two types of output stages is quite different. B+ sagging will be more noticeable with tube than SS.

Relative wise, SS amps usually have much more capacitance in their power supplies than tube power supplies have, relative to voltage and current drawn.

The differences between SE and PP can be quite small, with PP usually offering a little more bass while SE sacrifice a little bass for more midrange, depending upon the design. Phase splitters can be carefully designed for almost no perceptible degradation.

UL offers almost the same power output as pentode/tetrode, but with lower output impedance/greater damping factor. UL usually has wider frequency response at both ends of the audio spectrum.

Triode operation usually offers even wider bandwidth than UL (for a given OPT), and with lower output Z/greater damping factor than UL. Power output is much less in triode mode than either UL or Pentode/Tetrode mode. Some claim that triode operation is not as dynamic as UL/Pentode/Tetrode operation, but I won't comment more on that.

Cheers.