AMPS: High Power Vs High Current?

[speakerman39]

Folks, I have been doing a lot of reading on both integrated SS and/or tube amps. That being said, I keep coming across a strong preference for higher current amps as opposed to high power amps powering low sensitivity loudspeakers.

My Dentons are only 86 db sensitive which is a bit on the low end of scale. As such, would I be better off with a high current integrated amp OR a high power integrated amp? Does it make any difference albeit power wise between SS integrated amps and integrated tube amps? In other words, would I be better off with a high current SS integrated as opposed to a high power integrated tube amp and vice versa?

Just trying to understand the key differences between high power and /or high current. Need a real simple crash course. Can any of you offer me some help here? Lastly, anyone know anything about the hybrid tube amps that have a tube pre-amp section and a SS output section? Thus, tube IN and SS OUT. Any help appreciated. Thanks!


Cheers,

Phil

 

[TLS Guy]

Folks, I have been doing a lot of reading on both integrated SS and/or tube amps. That being said, I keep coming across a strong preference for higher current amps as opposed to high power amps powering low sensitivity loudspeakers.

My Dentons are only 86 db sensitive which is a bit on the low end of scale. As such, would I be better off with a high current integrated amp OR a high power integrated amp? Does it make any difference albeit power wise between SS integrated amps and integrated tube amps? In other words, would I be better off with a high current SS integrated as opposed to a high power integrated tube am and vice versa?

Just trying to understand the key differences between high power and /or high current. Need a real simple crash course. Can any of you offer me some help here? Lastly, anyone know anything about the hybrid tube amps that have a tube pre-amp section and a SS output section? Thus, tube IN and SS OUT. Any help appreciated. Thanks!


Cheers,

Phil

I think you are reading a load of BS. High power and high current really amount to the same thing. In higher impedance loads amps generally become voltage limited as there is not enough rail voltage to deliver more power. In lower impedance loads, the amp generally becomes current limited as not enough current is available to provide the power.

I think you have been on some audiophool sites where the authors are as stupid and ignorant as pig dribble.

The fact is the more linear voltage and current that can be supplied the better.

A hybrid amp makes no sense at all.

 

[speakerman39]

I think you are reading a load of BS. High power and high current really amount to the same thing. In higher impedance loads amps generally become voltage limited as there is not enough rail voltage to deliver more power. In lower impedance loads, the amp generally becomes current limited as not enough current is available to provide the power.

I think you have been on some audiophool sites where the authors are as stupid and ignorant as pig dribble.

The fact is the more linear voltage and current that can be supplied the better.

A hybrid amp makes no sense at all.

Well, I have always thought that higher current amps were able to handle lower impedance loads. What confuses me is that at lower impedances, amp power is generally increased. So, then more power translates to more current right? So, I get a lot of what you are saying. I am in total agreement regarding rail voltage/current limited.

So, you are saying it does not matter how the power is obtained via high power and/or high current? As such, lower sensitivity speakers just need more power to play as loud as higher sensitivity speakers all things being equal?

I do not know much about hybrids, but from what I am seeing they are becoming more common. Even Jolida makes one. Have never known them to produce junk. Just trying to discern the differences, if any, in these designs. Thanks!


Cheers,

Phil

 

[M Code]

Hmmm..
Big difference between high current and high power (voltage) designed amplifiers...
Todays' AVRs are typically designed for high voltage output power being tied into a looser regulated power supply so higher peak power is achieved with higher sensitivity loudspeakers... However certain old-school low impedance, low sensitivity loudspeakers are sealed box designs that need significant current to get the loudspeaker drivers moving as to output adequate SPL.. Thats why if one requires high current U better use a component power amplifier rather than an AVR.

A good comparison is in the automotive world of horsepower vs. torque.. High horsepower can provide higher top speeds but torque is what really gets the car moving..

Just my $0.02...

 

[speakerman39]

Hmmm..
Big difference between high current and high power (voltage) designed amplifiers...
Todays' AVRs are typically designed for high voltage output power being tied into a looser regulated power supply so higher peak power is achieved with higher sensitivity loudspeakers... However certain old-school low impedance, low sensitivity loudspeakers are sealed box designs that need significant current to get the loudspeaker drivers moving as to output adequate SPL.. Thats why if one requires high current U better use a component power amplifier rather than an AVR.

A good comparison is in the automotive world of horsepower vs. torque.. High horsepower can provide higher top speeds but torque is what really gets the car moving..

Just my $0.02...

Thanks! So which way would I be better off? Should I opt for a high current integrated SS amp or a high current integrated tube? Or it really makes little difference as long as the required power needs are met as TLS stated? Again, I have always thought that higher current amps can handle lower impedances better such as in powering multiple sets of speakers, no? What do you think of the hybrids that are becoming more common? Just curious is all.


Cheers,

Phil

 

[M Code]

Thanks! So which way would I be better off? Should I opt for a high current integrated SS amp or a high current integrated tube? Or it really makes little difference as long as the required power needs are met as TLS stated? Again, I have always thought that higher current amps can handle lower impedances better such as in powering multiple sets of speakers, no? What do you think of the hybrids that are becoming more common? Just curious is all.


Cheers,

Phil

PHIL..
IMHO...
1st things to consider are the room size, loudspeaker brand/model, source material and average volume SPL. A tube amplifier will be significantly limited in total output power compared to an SS amp. As the amplifier load decreases due either to additional connected loudspeakers or specific brand/model more current will be required. Tube amplifiers utilize an output transformer for impedance output and one simply changes its tap. Regarding hybrids no experience there. But I must tell U the later Hphex class-D amplifiers built by ATI sound pretty good to my ear..

Just my $0.02...

 

[KEW]

I believe the simple answer is that tubes do not last as long, are less efficient (more heat in your room), and cost more than SS.
The only "advantage" to tubes is they can color the sound which is why they are popular with guitar amps - they make the guitar sound fuller (like singing in the shower adds coloration makes my voice sound fuller). I suppose, in theory, if you thought your speakers sounded lean or austere, it might be possible to "lush them out" with a tube amp. But again, you are deliberately forfeiting accuracy.
So, unless that "advantage" is important to you, you are better off buying a more powerful SS amp with the extra money that the tube amp would cost. I would put the $600 Outlaw 5000 against any tube amp in that price range. I know it is a 5 channel amp, but having the bigger transformer and extra capacitance and only using it as a stereo amp gives you plenty of power and current (plus the flexibility to experiment/run it for up to 5 channels should you want)! Look at how much tube amp you can get for $600 and compare it to Gene's measurements on the 5000!
If you are considering spending more, I would say the Monoprice/ATI Monolith at $1000 for two channels (and add another $100 for each additional channel). Unless you need all 7 channels, I am fond of the 5 channel version ($1300) as a sweet spot as it adds the second transformer and again has the flexibilty to grow with you!

Lastly, if you end up deciding to "see for yourself", I would suggest the Audio by Van Alstine gear as probably being some of the better tube gear for the money (with decent power capability). Salk has partnered with Van Alstine for show displays/demos and that leads me to believe it is clean tube power!

But one of the first things that caused me to rule out tubes is knowing the tube would fail in the next couple to several years and the potential that it would do so in a very gradual/subtle way with out my realizing it until I played music I was very familiar with and heard the added distortion. I listen to a lot of new music all of the time and I might go several months before realizing that my nice system had been performing below its potential.

 

[TLS Guy]

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.

 

[speakerman39]

PHIL..
IMHO...
1st things to consider are the room size, loudspeaker brand/model, source material and average volume SPL. A tube amplifier will be significantly limited in total output power compared to an SS amp. As the amplifier load decreases due either to additional connected loudspeakers or specific brand/model more current will be required. Tube amplifiers utilize an output transformer for impedance output and one simply changes its tap. Regarding hybrids no experience there. But I must tell U the later Hphex class-D amplifiers built by ATI sound pretty good to my ear..

Just my $0.02...

Thanks for the info. Mr room is 1,440 ft. ^3 and my MLP is ~ 8' from my front-stage. I do NOT listen at extreme levels, but do like to rock out every now and then. Source will be a SONY 4K BR player and/or Pandora. Those are my main sources albeit cd's.

My main speakers are Wharfedale Denton 80th Anniversary speakers that I merely use for 2 Channel listening as my preference is on music. I do intend to experiment with some SACD in 2 Channel in the very near future. Never have owned a SACD and my Sony 4K BR can play it. I will, on occasion, watch a few 4K BR's that will also include my Klipsch R-25C center channel. There will be no surrounds and/or no subs involved. Most of my usage is listening to my music.

My question is not so much the tube vs SS thing, but rather high power vs high current designs. Have read several mentions that a high current amp w/less power is just as effective as a high power amp rated with higher power. That is where all of my confusion comes in to play here. Thus, I am trying to discern the significant differences between the two and what is audible and what is NOT. Where is one design superior to the other and vice versa.

Yes, I have much to learn about tube amps per se. Already working on that. That is why I have been reading about the new hybrids that are becoming more and more common. By all accounts they seem to be more affordable as well.

My Dentons have an 86 db sensitivity which is a bit low. Most of the owners of them seem to favor integrated high current tube amp designs. That is why I started this thread to learn more about high current vs high power amps. However, learning more about the differences between tubes and SS is also going to be of help. Personally, I am attracted to and prefer a more warmer musical presentation. That is the direction I have been heading in for a while now. Thanks!


Cheers,

Phil

 

[KEW]

Thanks for the info. Mr room is 1,440 ft. ^3 and my MLP is ~ 8" from my front-stage. I do NOT listen at extreme levels, but do like to rock out every now and then. Source will be a SONY 4K BR player and/or Pandora. Those are my main sources albeit cd's.

My main speakers are Wharfedale Denton 80th Anniversary speakers that I merely use for 2 Channel listening as my preference is on music. I do intend to experiment with some SACD in 2 Channel in the very near future. Never have owned a SACD and my Sony 4K BR can play it. I will, on occasion, watch a few 4K BR's that will also include my Klipsch R-25C center channel. There will be no surrounds and/or no subs involved. Most of my usage is listening to my music.

My question is not so much the tube vs SS thing, but rather high power vs high current designs. Have read several mentions that a high current amp w/less power is just as effective as a high power amp rated with higher power. That is where all of my confusion comes in to play here. Thus, I am trying to discern the significant differences between the two and what is audible and what is NOT. Where is one design superior to the other and vice versa.

Yes, I have much to learn about tube amps per se. Already working on that. That is why I have been reading about the new hybrids that are becoming more and more common. By all accounts they seem to be more affordable as well.

My Dentons have an 86 db sensitivity which is a bit low. Most of the owners of them seem to favor integrated high current tube amp designs. That is why I started this thread to learn more about high current vs high power amps. However, learning more about the differences between tubes and SS is also going to be of help. Personally, I am attracted to and prefer a more warmer musical presentation. That is the direction I have been heading in for a while now. Thanks!


Cheers,

Phil

Have you seen any impedance/phase curves for the Dentons? I think that is what would help you with the current vs power question. I think more current is required for lower impedances.

 

[speakerman39]

I believe the simple answer is that tubes do not last as long, are less efficient (more heat in your room), and cost more than SS.
The only "advantage" to tubes is they can color the sound which is why they are popular with guitar amps - they make the guitar sound fuller (like singing in the shower adds coloration makes my voice sound fuller). I suppose, in theory, if you thought your speakers sounded lean or austere, it might be possible to "lush them out" with a tube amp. But again, you are deliberately forfeiting accuracy.
So, unless that "advantage" is important to you, you are better off buying a more powerful SS amp with the extra money that the tube amp would cost. I would put the $600 Outlaw 5000 against any tube amp in that price range. I know it is a 5 channel amp, but having the bigger transformer and extra capacitance and only using it as a stereo amp gives you plenty of power and current (plus the flexibility to experiment/run it for up to 5 channels should you want)! Look at how much tube amp you can get for $600 and compare it to Gene's measurements on the 5000!
If you are considering spending more, I would say the Monoprice/ATI Monolith at $1000 for two channels (and add another $100 for each additional channel). Unless you need all 7 channels, I am fond of the 5 channel version ($1300) as a sweet spot as it adds the second transformer and again has the flexibilty to grow with you!

Lastly, if you end up deciding to "see for yourself", I would suggest the Audio by Van Alstine gear as probably being some of the better tube gear for the money (with decent power capability). Salk has partnered with Van Alstine for show displays/demos and that leads me to believe it is clean tube power!

But one of the first things that caused me to rule out tubes is knowing the tube would fail in the next couple to several years and the potential that it would do so in a very gradual/subtle way with out my realizing it until I played music I was very familiar with and heard the added distortion. I listen to a lot of new music all of the time and I might go several months before realizing that my nice system had been performing below its potential.

Thanks Kurt for your reply. This post is very helpful no doubt. However, my question centers more on high current vs high power integrated amp designs. I used the example of a tube vs a SS true. But, I am just trying to discern the differences of high current vs high power designs in general.

As you know, I am fascinated with tube amps and have been for as long as I can remember. Eventually, I am looking for something that will power my Dentons as loud as I need them to be. That though is the million dollar question as well. I do NOT listen at insane levels. Much more about SQ than SPL. But, I also like a more warmer presentation musically speaking.

There is no doubt in my mind that the tubes can do just that. Have not heard too many people describe a SS integrated amp as being very warm. As such, that is why I have been interested in tube amps for a long time now. My goal is to power my Dentons to get as much warmth out of them as I can. In the end, it really doesn't matter to me if it comes by way of a SS amp, tube amp, and/or a hybrid. That is, given my budget of say $500.


Cheers,

Phil

 

[speakerman39]

Have you seen any impedance/phase curves for the Dentons? I think that is what would help you with the current vs power question. I think more current is required for lower impedances.

No, I have not. But, honestly I do not know how to read them very well. My eyesight is not the greatest being diabetic. Care to interpret it for me? Or, explain to me how to read the impedance curves better? Might as well learn something new here I always say.

Cheers,

Phil

 

[speakerman39]

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.

Very well written. I do understand some of it. Honestly, not all of it. But, it serves as a good outline for me to do some more research and perhaps learn a bit more about amps altogether. Thanks for taking the time to write this up. It is most appreciated.


Cheers,

Phil

 

[speakerman39]

Have you seen any impedance/phase curves for the Dentons? I think that is what would help you with the current vs power question. I think more current is required for lower impedances.

Kurt, I found this here:

http://www.hi-fiworld.co.uk/index.php/loudspeakers/65-reviews/519--wharfedale-denton-80th-anniversay-edition.html?showall=1

I noticed that they claim the Dentons are 4 ohm speakers and not 6 ohm as rated. But, I do not understand how to ascertain much info from the impedance curve. Feel free to enlighten me here. Thanks!


Cheers,

Phil

 

[mtrycrafts]

Phil, you should play with Ohm's law and see what is needed and how it is not really an issue if an amp can deliver power that you need.

10V on the rail will not deliver a lot of current no matter what. You have a 3 Ohm load, 10V and you get 3.3A, period. You will not get more current with that 10V. It ain't an arc welder where your load is next to 0.

 

[speakerman39]

Phil, you should play with Ohm's law and see what is needed and how it is not really an issue if an amp can deliver power that you need.

10V on the rail will not deliver a lot of current no matter what. You have a 3 Ohm load, 10V and you get 3.3A, period. You will not get more current with that 10V. It ain't an arc welder where your load is next to 0.

Okay using your analogy here I read that the Dentons are actually 5.6 ohm overall. Using the 10v rail you gave that would equal 1.79 amps. Where or shall I say why did you mention the 10v? Just using it as an example? Okay so 1.79 amps at 10v. What does that actually mean? How would I apply that info? What can I discern from it? Thanks!


Cheers,

Phil

 

[TLS Guy]

Okay using your analogy here I read that the Dentons are actually 5.6 ohm overall. Using the 10v rail you gave that would equal 1.79 amps. Where or shall I say why did you mention the 10v? Just using it as an example? Okay so 1.79 amps at 10v. What does that actually mean? How would I apply that info? What can I discern from it? Thanks!


Cheers,

Phil

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.

 

[Bucknekked]

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.

"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.

 

[mtrycrafts]

Okay using your analogy here I read that the Dentons are actually 5.6 ohm overall. Using the 10v rail you gave that would equal 1.79 amps. Where or shall I say why did you mention the 10v? Just using it as an example? Okay so 1.79 amps at 10v. What does that actually mean? How would I apply that info? What can I discern from it? Thanks!


Cheers,

Phil

Yes, that is what it was, an example. You need to see what is the power rating of the amp in question, how it was rated, and into what load.


If you have speakers that dip to 2.5 Ohms, you will need more power capability. And, of course, speaker sensitivity matters as well. Also, rated power is continuous power, hardly what music or movie is about.

With your example above your amp needs to deliver 17.9 Watts. So, if that is the case, speakers 90dB sensitive in room should drive it to 100 dB for sure.

 

[PENG]

I agree with TLSGuy and others, 95% anyway that it's practically a moot point at best.

As mtry mentioned, ohm's law (okay let's include the power formula too) governs. If you buy an amp that can do 100W into 8 ohms, then as long as it is a well designed class AB amp, it will do around 125 to 150W into 4 ohms, obviously not continuously but for long enough to suit most music listening applications and a lot of speakers with dips to the 3 or 4 ohm range. Even my old Denon AVR-3805 that weighs 37 lbs 10 oz soak and wet had been tested to 2 ohms (even 1 ohm iirc) without going up in smoke and still able to put out close to 100W (again iirc).

So Phil, just re-read some of the S&V reviews on the AVR brands of the one you currently own and sleep well. Or be prepared to restrict your choices to the truly and literally "high current" amps that just keep doubling down (approximately) by Krell, Boulders etc.

Alternatively, you can also consider (or pretend) any mid range to flagship AVR as truly high current design if you de-rate them by a factor of 2 to 4. Example: A 140WPC Denon, de-rated (by you) to 50WPC will qualify as a truly high current amp, much truer than any HK AVR of the old days that were considered by many as high current amps, yet almost always get beaten by Denon's in S&V (HTM back then) by a good margin.