Which camp are you in ??? And why are you there ???

[mike stehr]

dp

[sebrof]

He was kidding he never posts more then ironic little one liners. I think he's shocked (Or maybe dissapointed) we didn't end up in a flame war.

Is this where I bring up the Jubilee's or is this the wrong camp?

No. This a SET vs PP thread, cinema speakers are off-topic...

Wrong - This WAS a SET vs. PP thread.

Now it's just a big group hug. Sorry Jacksonbart.

[edwinr]

I haven't read the whole thread, but If you know you only need 2 watts, you can't just design/buy a 2 or 3 watt amplifier. At home my current tube amplifier punches out around 18 clean watts per channel. I know I probably only use say 5 or 6 watts during normal listening sessions. But if my amplifier was only 5 or 6 watts per channel, where's the headroom?

I know a little four cylinder car will hold the same cruising speed as a larger, V8, and use less fuel. But the big 'ol V8 will be just so much smoother and more pleasant to drive.

While we can argue about the relative merits of SET vs PP, my big problem with most SET amplifiers I have heard, is the lack of power and drive. In saying that, most of the SET amplifiers I have heard sounded really nice within their very limited power envelope.

I guess the best way to take advantage of the very low powered SET sound, is to use them with extremely sensitive transducers. In larger rooms playing fairly dynamic music, will my Belles be sensitive enough? Maybe a pair of Avantgarde Trio's with their 109db/watt sensitivity may be a better match... So I agree, you cannot fairly judge any amplifier unless you factor in what loudspeaker you are going to use. My 'little' CEC Classic Tube 53 sounds awful on my study's little bookshelf monitors (Wharfedale). If I had originally heard this amplifier on these speakers, I would never have bought it!

[CECAA850]

You make WAY too much sense Mark.

[sebrof]

I guess the best way to take advantage of the SET sound, is to use them with extremely sensitive transducers.

Well, more generally than that, the best way to use them is to keep them operating within their design criteria. So, more efficient drivers and lower volumes both help to achieve that goal.

I think it has to do with more than just rated efficiency. My SET seemed to really open up with a benign 8 ohm load, single driver speaker. Even though they are rated at 97db and my KHorns are rated at 104db, they both seem to play to about the same level before things start to go south. Doesn't impedance dips and peaks and phase angle at those points matter a lot also?

[NOSValves]

I think it has to do with more than just rated efficiency. My SET seemed to really open up with a benign 8 ohm load, single driver speaker. Even though they are rated at 97db and my KHorns are rated at 104db, they both seem to play to about the same level before things start to go south. Doesn't impedance dips and peaks and phase angle at those points matter a lot also?

Bingo you got it! Then factor in that music can send all kinds of different impedance dips and peaks in nano second changes back to the amplifier.... this is why I personally believe SET amps and even triodes in general have problems dealing with more complex music... triodes just can't seem to handle those wild impedance curves well to me. My own VRD amp with its Triode/Ultra Linear swtich can show you that in quickly... play some Jazz, acoustic or vocals it sounds better in triode mode. Throw some big band, swing music or rock and roll in and Ultra Linear quickly walks all over Triode.

[bkrop]

Classic money quote from mdeneen

"My problem with with the Prius is that it won't tow my boat,"

Priceless analogy!

[DrWho]

Those two sentences imply a logical contradiction, or a misunderstanding. "Headroom" is only meaningful if it gets used. If you are using the "headroom" above the 5W, then clearly you need an amplifier bigger than 5W. If you are NOT using it, you don't need it. There's no in between or maybe to it.

I think headroom in this case has more to do with the fact that an amplifier's distortion curve is not flat, and peak power is usually measured at ~10% THD....not somewhere you want to be operating.

[edwinr]

I know I probably only use say 5 or 6 watts during normal listening sessions. But if my amplifier was only 5 or 6 watts per channel, where's the headroom?

Those two sentences imply a logical contradiction, or a misunderstanding. "Headroom" is only meaningful if it gets used. If you are using the "headroom" above the 5W, then clearly you need an amplifier bigger than 5W. If you are NOT using it, you don't need it. There's no in between or maybe to it.

When I suggest you should know how much power you need, I mean how much TOTAL power, not just how much average power. Sure, if you mostly listen at an average power of 5W (which is quite high on horns), you will for darn sure need a much larger amp than 5W. You have to account for peak power and for dynamic range when you figure your power needs.

While we can argue about the relative merits of SET vs PP, my big problem with most SET amplifiers I have heard, is the lack of power and drive.

Then it's not the right amplifier for you - that's easy. The power is severely limited. So, if you need to exceed it, that is a prima facie argument that it is the wrong selection. If I said, "My problem with with the Prius is that it won't tow my boat," you'd laugh at me right? Of course that's a problem - the Prius is not meant for towing boats.

I guess the best way to take advantage of the SET sound, is to use them with extremely sensitive transducers.

Well, more generally than that, the best way to use them is to keep them operating within their design criteria. So, more efficient drivers and lower volumes both help to achieve that goal.

Since everyone else is quoting - I'll do it too!

Okay, Mark, you're kind of making sense. The peak power thing works for me. If I think about it, it would be rare given the swings in a musical signal for ANY amplifier to output it's continuous power rating.

And regarding the complex load that many speakers exhibit, to what extent does the crossover influence the ability of a SET amplifier to go loud(er)? I am thinking that the crossover does have a major influence, and this may be why some SET users favor single driver designs such as those manufactured by Fostex and others.

[HPower]

Mark,

It is no wonder why you build (built) great Hi Fi, and why so many cherish your gear...

You make sense [8]

[NOSValves]

Mark,

It is no wonder why you build (built) great Hi Fi, and why so many cherish your gear...

You make sense

Yup Mark is very gifted at both written word and verbal communication. I've stated many times he missed his professional calling in life. He should of been a college professor the world would of been better for it. In essence Mark has just put into written form what was already glazed over and over in this thread by many less talented in the art of written debate.

[davis419b]

Mark,

It is no wonder why you build (built) great Hi Fi, and why so many cherish your gear...

You make sense

Yup Mark is very gifted at both written word and verbal communication. I've stated many times he missed his professional calling in life. He should of been a college professor the world would of been better for it. In essence Mark has just put into written form what was already glazed over and over in this thread by many less talented in the art of written debate.

Coming from a very gifted guy yourself you could not have said it better !

[SSnyder]

You can't properly select an amplifier without first deciding how loud you want to play music. Not knowing how loud you want the music to be is akin to buying a tow truck without knowing what you intend to tow with it.

There's a good reason the word "power" is embedded in the term power amplifier. The capability to produce a given level of power will determine to a great extent what topologies are useful, practical or economical. And, topology will subsequently determine what kind of sonic signature you can expect from the sound.

There are all these comments about specific amplifier topologies, but they are too often made out of context of their application. There are some exquisite sounding 1/4W amplifiers, for example. Never heard them? Well, put on your headphones and get a high quality headphone amplifier sold by many people. Well - ok, I tossed in a ringer there, but only to show that power must be the very first consideration and context for evaluating any amplifier. No one would seriously attempt to evaluate a 1/4W headphone amp on a pair of living room speakers.

It's a faulty assumption to say that anything called a high fidelity amplifier can be hooked up to any speaker, playing any music, at anyone's listening level, and be compared to some totally different amp under the same conditions. That's just silly beyond discussion.

We don't take a truck and a sports car and run them over the same course for comparison just because they are both "vehicles." A guy doesn't buy a Miata, hook it up to a 25 ft. boat, and then *** that the towing is lousy. But we do that with amplifiers all the time.

The question of loudness has plagued listening tests for as long as I have been around HiFi, which is 40 years. When Joe says "loud" he means something utterly different than when Pete says "loud." I've witnessed this too many times to count. Loudness is relative to taste, just like spiciness is relative to taste.

There are a few things we absolutely know through careful testing. We know that very subtle changes in loudness change our perceptions of what we are hearing. We know that the human ear is mostly insensitive to modest amounts of harmonic distortion. We know that there is more to listening preference than the simple measurements often quoted as benchmarks for amplifiers. And we know that misusing an amplifier to the point where the circuits are clipping is usually very obvious and very annoying.

Given those things you already know, you can't expect a 2W amplifier to play as loudly as a 200W amplifier and remain within it's design ranges. Something has to give. And, the first thing that must obviously give is loudness.

If a person believes that need a 200W amplifier to play at the loudness they like, why would they even look at a 2W amplifier? If you never go louder than a 2W amp, why would you want to try a 200W amp for that purpose? Power costs money, and more power costs more money. So, buying more power than you will ever need means the money you spent is going towards producing power (e.g a bigger transformer, or more output sisters) than you will never use. Money wasted there can't be used in other places in the design.

If you begin with knowing your power requirement, then you can say, "Ok, every amp with at least that much power is in play for consideration."

If all I need is 2W of power, I can put every amp with 2W or more into my basket of possible choices. If I then compare them, using my appropriate listening level and music, I have the best chance of coming out with the one I like best. But if I need 50W, and I put 2W amps in the basket, I am just making a hash out of the selection process.

The argument over "what is the right loudness" is an entirely separate argument. I have no idea why, but there is some contingent of people who insist on defining what is proper loudness. If it doesn't sound like a 100 piece marching band in your living room, you are all wet, and not doing the right things, goes the commentary. I find that argument to be utterly pointless. I am only, ever going to listen at what loudness is comfortable to me. I could care not one iota if it is "concert hall level" or "marching band level" or "rock concert level" or "original loudness" or any other such arbitrary dictum.

So then, there will be applications where a 500W amp is useful, and applications where a 1W amp is useful. The only people that ought to consider buying the 1W amp are those who plan on listening at levels comfortable for those amps to handle.

Once that is established - that you aren't demanding more power than the amp can deliver - then you are left with what sounds best to your ears. And here finally, is where topologies can be appreciated for their benefits, and criticized for their shortcomings.

Anyone who has ever sat down with a blank sheet of paper and a pencil to design a new amplifier from scratch understands immediately that choosing topology is the process of arranging tradeoffs. There is no "best" topology, just as their is no "best" car engine. You start with some clear, definable objectives for the final result. Then you must see how each topology, and the many choices within it, will reach that set of outcomes. To say a topology is "invalid" just because it is old, is like trying to discount magnetism because it was discovered 2000 years ago. My goodness, if mere age was important, then the folded horn would have been rendered moot long ago! The topologies available today, each have their own advantages and disadvantages. The amplifiers exist because the designer felt the benefits outweighed the drawbacks to meet his/her design objectives. So, if in doubt, find out what the designer intended. If he/she says it's that way because that's the "only right way" to design an amp, run like the wind because they don't know what they are talking about. But assuming they give you a reasoned answer based on the pluses and minuses, you can use that to see if it fits your objective.

Cars have intended uses. Airplanes have intended uses. Amplifiers do too. If you exceed the intended uses of any of these things, you will have less than optimal results. Know first what you want to accomplish - find out what each can do - and then make a selection. The first step in that process has to be knowing what loudness you need.

he suttleties of music can not be understod by filistines HOW LOUD WILL IT GO BOOM BOM BOOM I'LL TAKE IT

A PREFESIONAL DRIVER COULD FULLY TAKE OF A CHEVET'S FULL CAPIBILITY BUT I BET NO PREFESINAL DRIVERS HERE. LAY-MAN WOULD LOOSE IN CORVET! TO PREFESIONAL RACECAR DRIVER IN CHEVET!!! SORRY FOR ALLCAPS DID NOT notive until now.

[oldmako]

I have no idea what this thread is about. Therefore I am not in either camp. I am wandering around lost in the woods. This discussion (and you gents) are several orders of magnitude over my head. But, I am trying to learn, as this stuff is both confusing and fascinating. Thanks for the interesting discussion. I'll go back to my old vintage SS stuff and shut up now.

[sebrof]

I have no idea what this thread is about. Therefore I am not in either camp. I am wandering around lost in the woods. This discussion (and you gents) are several orders of magnitude over my head. But, I am trying to learn, as this stuff is both confusing and fascinating. Thanks for the interesting discussion. I'll go back to my old vintage SS stuff and shut up now.

The question - What camp are you in, Low Power Single Ended or High(er) power Push Pull?

My answer - It's all good if done properly, including vintage Solid state.

[SSnyder]

well all pizza is good ever ate any bad pizza but som is better then others by a country mile the nowances are loss to the glutanus herd

now vulay vus comprende?

[SWL]

djnick....is that you? [:S]

[HPower]

well all pizza is good ever ate any bad pizza but som is better then others by a country mile the nowances are loss to the glutanus herd

now vulay vus comprende?

OK, which one of you guys left the gate opened [*-)]

[leok]

Can you audit the Channel Islands D•100B Monoblocks?

Clean low power that I think is better than SET and plenty of high power that is just as clean.

Leo

[Ski Bum]

Thanks Mark and everyone for sharing their opinions.

I'm in the 'music' camp. Got a couple SETs, more than a few conventional ss amps. They seem to all function adequately for what I ask them to do, but the SET's do have that almost psychedelic purity thing going for them. Mine even play nice with some speakers with which they should never work (multiple driver, complex crossovers, power robbing zobel networks...but the pairing works fantastically well, go figure).

Does anyone have experience with the old Quad 'current dumping' amps? Plenty of power, can push any load, unconventional but simple circuit with low part count, supposedly class A output. I've been curious about these for a while.