AMPS: High Power Vs High Current?

[pcosmic]

This is really a pretty simple proposition that idiots obfiscate.

A tube is a voltage amplifier it, is not and can not be a significant current amplifier.

A transistor and its derivations, can be both a voltage and current amplifier. It is in fact an excellent current amplifier.

Now a preamp is a voltage amplifier. A power amplifier needs to be both, but primarily a current amplifier.

So as a preamp the score is more even. However ICs have better specs and especially better S/N and reliability. So really no contest. Absolutely no advantage of a tube over SS.

In the power amp department the transistor wins hands down. No contest at all.

In order for a tube to be a power amp and current amp, it needs either a very high impedance load, or a transformer between output device and load. That entails huge disadvantages. For one thing the loudspeaker needs to be chosen very carefully. Big swings of impedance are a no no, or the output will tend to follow the impedance curve. Horror of horrors!

A good SS amp can provide enormous current if resources are devoted to it. This enables it to ideally cope with the impedance drop of baffle step compensation.

To maintain that a tube amp has any reasonable advantage over an SS amp is totally preposterous.

The trouble is there are know nothings abounding expounding far fetched nonsense.

The fact this argument persists is testimony to a poor educational system, and the avarice of those prepared to profit mightily from ignorance of others when they know better.

The impedance overall means nothing. It is the impedance in the power range that matters especially below BSC.

It really is not difficult. Lets take a 20 volt rail voltage. If the impedance is 10 ohms then the maximum current that could be delivered is 2 amps. In practice it would be a little less, but lets ignore that. So the power delivered would be 40 watts. Now lets assume we have a good linear SS amp. Now lets make the speaker impedance 5 ohms. So the current will up to 4 amps and the power to 80 watts. If it is a really linear amp dropping the impedance to 2.5 ohms will be 8 amps, and the power 160 watts. If it can't deliver the current for the power required by the input then there will be clipping. In practice an real world amps are not that linear, and the power into 2.5 ohms will probably be closer to 120 watts.

Now lets make the impedance 20 ohms. In an SS amp it can't deliver a higher voltage than the rail. So voltage clipping will occur at above 20 watts.

Now lets take a tube amp. We can get any voltage we want, by selecting an appropriate secondary tap on the output transformer. So we can match power to any impedance and have the power constant through any range of impedance as long as it is constant with frequency

However here is the rub. Few loudspeakers have constant impedance. So if we match a tube amp to the mean impedance of say 8 ohms, and say it delivers 20 watts max into the load. Lets see what happens in a real world load. If the impedance is 4 ohms at 200 Hz it will deliver 10 watts at that frequency. Now say the impedance is 6 ohms at 900 Hz, it will deliver 15 watts at that frequency. So this is how at max power at the clipping point a tube amps response starts to follow the impedance curve. So if you have a tube amp speaker selection has a huge impact on the sound you get. The reason being is that tubes can not increase current as load impedance is reduced, like SS amps can.

Now you can see why highly sensitive speakers with very simple, and especially no crossovers, are so popular in the tube community. Back in the tube days I used pretty much exclusively full range drivers with no crossover.

Lastly your quest to look at high current versus high power is just nonsensical. The two are the same side of the coin. A high powered amp is high current. A high current amp is high powered.

A low current amp that was high powered would need a high output voltage and a very high impedance load. That situation is not encountered in real world loudspeakers.

You see power is Voltage X Current, always, no exceptions. So at a given voltage then you can only increase power by dropping load impedance so current can rise.

This is really simple very basic stuff about which there can be no argument. Don't get confused by the ignorant pig dribblers wasting ink in the Audiophool press. These people are unfortunately too numerous to count, and make the Internet full of error, which is inexcusable since this matter is so simple.

Bravo! You have slayed many audiophools on this thread, my friend. We need more slaying like this on all the forums.

 

[pcosmic]

I aced Calculus III and Engineering Mathematics I, but I can't remember anything now to save my life.

These days there is an app for everything.

Back then using Calculators was a big thing. Now we don't even use calculators. Just use apps on phones.

Ah Calc III (Math 250!), I remember that. It felt like the hardest class ever when i was a wee young undergraduate drunk a lot. But, then, a decade later i was sitting in Math 8xx, "Stochastic Adaptive Control". I didn't have the pre-requisite, a.k.a, Math 7xx (some kinda advanced prob stats class). I sat in class and I could only see physics and math PhDs with mad hair and mutated facial features sitting next to me. There was no frat boy engineer in there, just me! Fear and loneliness gripped me hard, young lads. Everything on the blackboard looked like Egyptian hieroglyphics for a month. I went up to my advisor's office and screamed in agony, "wha,,,wha, wha did you do this to me? i don't have the pre-requisite and i haven't slept in days". She sez " But, youse is a PhD candidate, youse should be able to handle it!" ......Anyways, long story short, i did get a B in that class and killed my 4.0. You couldn't pay me worn out soul to take a math class EVER AGAIN, young lads!

 

[Bucknekked]

I don't know where we are in the wonderfully esoteric discussion these days. But, taking a look back through this thread I am reminded of one of my very favorite posts by @TLS Guy . I will give it a bump here because it makes me smile and laugh just to read it once again.

TLS Guy said: This is really simple very basic stuff about which there can be no argument. Don't get confused by the ignorant pig dribblers wasting ink in the Audiophool press. These people are unfortunately too numerous to count, and make the Internet full of error, which is inexcusable since this matter is so simple.

Bucknekked then said : "ignorant pig dribblers". I think that will be my favorite quote for the weekend. Up until I saw this, "audio cork sniffers" was the reigning favorite. I love a good piece of visual imagery.

 

[Gmoney]

Old thread, has anyone seen speakerman39? sure hope his doing good and ok

 

[AcuDefTechGuy]

Old thread, has anyone seen speakerman39? sure hope his doing good and ok

Good point. I have not seen him for a long time.

 

[Gmoney]

Good point. I have not seen him for a long time.

yeah I know he lives by himself in a apartment
He sure was cool dude to chat up audio with.

 

[Pogre]

I don't know where we are in the wonderfully esoteric discussion these days. But, taking a look back through this thread I am reminded of one of my very favorite posts by @TLS Guy . I will give it a bump here because it makes me smile and laugh just to read it once again.

Bucknekked then said : "ignorant pig dribblers". I think that will be my favorite quote for the weekend. Up until I saw this, "audio cork sniffers" was the reigning favorite. I love a good piece of visual imagery.

A worthy bump. I missed that one!

 

[Pogre]

yeah I know he lives by himself in a apartment
He sure was cool dude to chat up audio with.

He posted here not too horribly long ago. Don't remember where tho...

 

[Gmoney]

He posted here not too horribly long ago. Don't remember where tho...

I know has girlfriend in the Philippines wonder if he finally went he did say he was saving up to go

 

[Pogre]

I just read the first and second pages. I think ol' Phil just wanted someone to tell him a tube amp would work better than ss with his Dentons, lol.

 

[Gmoney]

I just read the first and second pages. I think ol' Phil just wanted someone to tell him a tube amp would work better than ss with his Dentons, lol.

Yeah Sure hope he doing well miss the ole dude! I know he likes bookshelve speakers. I thought of getting a tube amp just for the Cool factor

 

[Pogre]

Yeah Sure hope he doing well miss the ole dude! I know he likes bookshelve speakers. I thought of getting a tube amp just for the Cool factor

Phil is a bit of an odd duck, not that that's necessarily a bad thing. Seemed like he was constantly changing out audio gear. Never really satisfied.

 

[Gmoney]

Phil is a bit of an odd duck, not that that's necessarily a bad thing. Seemed like he was constantly changing out audio gear. Never really satisfied.

yeah he would buy speakers a lot than sell them off than buy more. A true Audiophile

 

[Mikado463]

who says tube amps can't help create a 'mesmerizing' experience !! .............

 

[KEW]

Old thread, has anyone seen speakerman39? sure hope his doing good and ok

I pinged him the other day to check on him and he is still around and kicking. He is taking a little bit of a break from the forums. I have done this on occasion myself when I realize I am getting behind on other aspects of life!
I always can count on the guys here to keep the wheels rolling during my hiatus!
As for this thread, it is pretty old, but I know I will often read something about someone enthused with a new piece of kit and the enthusiasm is contagious. I find myself wanting to try what the other person is excited about!
I have however spoken with Speakerman39 many times about system options and he is pretty level-headed about it and will make a post like this to do a reality check before going out and buying something. I wish more people did that! As you know we see way too many people who buy then look for confirmation/admiration of their gear which they don't get.
It is a disappointing aspect of this hobby that there are guys who will talk like they have a very good knowledge of electronics and come up with some BS and they know just enough to make it sound good. It can be very hard to resolve their story with other opinions from seasoned audioholics with an electronics background. I appreciate the way Phil confronts this directly in a thread like this one he started, as you can be sure there are others who have the same question but are not willing to pursue it to the extent he does!
He knows it when he hears what he likes and is ever "questing" for the next speaker!

 

[William Lemmerhirt]

I don't know where we are in the wonderfully esoteric discussion these days. But, taking a look back through this thread I am reminded of one of my very favorite posts by @TLS Guy . I will give it a bump here because it makes me smile and laugh just to read it once again.

Bucknekked then said : "ignorant pig dribblers". I think that will be my favorite quote for the weekend. Up until I saw this, "audio cork sniffers" was the reigning favorite. I love a good piece of visual imagery.

Indeed, his British eloquence knows no bounds! I always appreciate his directness.

 

[Bucknekked]

It is a disappointing aspect of this hobby that there are guys who will talk like they have a very good knowledge of electronics and come up with some BS and they know just enough to make it sound good. It can be very hard to resolve their story with other opinions from seasoned audioholics with an electronics background.

@KEW
One of the most disappointing things in this hobby for me was when I started getting a look at some of the systems various OP's have installed at their homes. Back before I joined AH I did not have a regular forum home so I was adrift in a sea of hyperbole. One day there was a pissin' contest on a forum between several OP's and part of the solution was to post pictures of what they actually had installed. That post was a revelation to me.

One of the loudest, nastiest and most opinionated OP's in that thread posted his system and I was shocked at the junk that was in the room. Not just the audio gear, but, the living conditions and the room were dystopian at best. The reason for his nasty viewpoint was pretty clear: they guy lived in a dung heap and his gear was fit for the room.

One of the things I appreciate here on the AH is most people post what they play their music or theater on. Pictures abound. Descriptions are complete. It doesn't tell you everything, but, it does give each OP some creedance. @TLS Guy is a great example. His posts can be direct and sometimes tough on the OP. But, when you look at his systems and background and what he's accomplished in the real world, he has earned his stripes. So it goes around the forum with 90% of the OP's: they are willing to back up their opinions with the gear they run. It doesn't always make them correct (oh, no !), but it gives them a leg to stand on.

 

[Gmoney]

Yeah what’s up when they say Hi current and they go 35 amps peak? PENG what you say on this

 

[M Code]

Yeah what’s up when they say Hi current and they go 35 amps peak? PENG what you say on this

A high-current spec has little meaning unless..
They disclose more info about the measuring procedure, including load, time interval, driving frequency...

 

[Gmoney]

A high-current spec has little meaning unless..
They disclose more info about the measuring procedure, including load, time interval, driving frequency...

thanks M!