How much power is enough power?

[Hocky]

haha, I understand. I'll be looking forward to it. ;-)

 

[Neil H]

Class A Power

I would like to pose a related question to how many watts is enough.

How much current is enough. Most people talk in terms of 100 watt, 200 watt etc. power ratings. However, I would like to know how much current is really needed and what people mean when they say high current.

I have a Gryphon DM100 which is a pure class A amp rated at 100 watts. This is a quite large and heavy amp and seems to have much more power than the Classe 25 (rated at 250w into 8 ohms) that I use to have. It is running Summits at the moment but I have also had it powering Prodigys in the past which it did with ease.

 

[roberto]

I have a friend that uses a Jolida 300B (9 Watts/ch) with Vantage and he and I like what we listen, and it is a clean very musical sound...happy listening,
Roberto.

 

[kach22i]

I have a friend that uses a Jolida 300B (9 Watts/ch) with Vantage and he and I like what we listen, and it is a clean very musical sound...happy listening,
Roberto.

It's the first watt that counts most.

 

[tonepub]

It's the first watt that counts most.

There's no such thing as "the first watt."

There's no amplifier that sounds different with watt 1 than it does with watt 2 through infinity. And unless you are listening at whisper soft volume, you're always listening with a lot more than one watt.

Even with the CLX, which is fairly efficient, even at moderate levels, those meters jump up in the 3-400 watt range on peaks.

An amplifier either sounds good or it doesn't, and it either has a lot of dynamic range or it doesn't.

Unless you've got single driver speakers that have an efficiency of about 103db, you're always using a lot more power than you think.

 

[Dominick22]

I would like to pose a related question to how many watts is enough.

How much current is enough. Most people talk in terms of 100 watt, 200 watt etc. power ratings. However, I would like to know how much current is really needed and what people mean when they say high current.

I have a Gryphon DM100 which is a pure class A amp rated at 100 watts. This is a quite large and heavy amp and seems to have much more power than the Classe 25 (rated at 250w into 8 ohms) that I use to have. It is running Summits at the moment but I have also had it powering Prodigys in the past which it did with ease.

Neil,

While I am not an expert regarding class a, a/b, etc....I think that the main difference between the classes is how the power supply is circuited. I think that the main reason a class a amp is generally bulkier and heavier has more to do with its need for massive heat dissipation. I think this is because class a amps are actually inherently less efficient than other classes.

Someone please jump in if I am wrong because I am drawing from a very limited memory on this subject.

Dominick

 

[Neil H]

Neil,

While I am not an expert regarding class a, a/b, etc....I think that the main difference between the classes is how the power supply is circuited. I think that the main reason a class a amp is generally bulkier and heavier has more to do with its need for massive heat dissipation. I think this is because class a amps are actually inherently less efficient than other classes.

Someone please jump in if I am wrong because I am drawing from a very limited memory on this subject.

Dominick

What I was trying to get at is that mine is a high current class A amp. I am just wondering what is meant by that term. People mention high current but they never quote a a number of amps. I am wondering how many amps makes a high current amp or is it more complicated than just a number.

 

[Rich]

Neil,

Your amp is considered "high current" because of its incredibly beefy power supply and the tons of big capacitors it has. The fact that it is biased in Class A doesn't really play into how much current it can generate. Current is all about the power supply and beefy banks of caps. Most amp manufacturers don't give specs on how much current their amps generate, so it is not a spec that is easy to compare. The way to find out if an amp is beefy in the current department is to do a little research on how it is built.

If an amp can double its wattage output with a halving of impedence, then that is often a good indication of its current output. An amp that can remain stable and continue to double wattage all the way down to one ohm is generally considered a beast of an amp. But that is not always the case. With Class A and some tube designs, the amps put out the same wattage into any impedence load, but still can provide plenty of current. So you really have to look at the power supply and capacitor storage to know for sure.

 

[kach22i]

1. There's no such thing as "the first watt."

2. There's no amplifier that sounds different with watt 1 than it does with watt 2 through infinity. And unless you are listening at whisper soft volume, you're always listening with a lot more than one watt.

3. Even with the CLX, which is fairly efficient, even at moderate levels, those meters jump up in the 3-400 watt range on peaks.

4. An amplifier either sounds good or it doesn't, and it either has a lot of dynamic range or it doesn't.

5. Unless you've got single driver speakers that have an efficiency of about 103db, you're always using a lot more power than you think.

Note: added matching numbers to comments as a key

My opinion differs on just about everything you have stated, and here is why:

1. I used a Radio Shack power meter (measured in watts) back in 1978 with my 25 watt Scott receiver and 12 woofer Audio Lab (Fisher) speakers, the 1-watt rule applied to that set-up. Not trying to impress anyone (or make you laugh), just being honest about my first hand experience.

2. Amps and speakers sound different at different sound levels. "Different" in this case applies rather broadly and can be broken down into at least two situations. A: Small speakers tend to sound better than large speakers at low volumes, and not all speakers and amps have the same synergy at low volumes as high volumes. B; Amp clipping and straining "through infinity" can change the character of the amp sound and the way the loudspeaker presents it to the human ear. In addition I've gone stereo stores and listened to different amp/speaker combinations and low, medium and loud levels. They all acted differently, some excelled at low levels, others at high levels, and others in the middle. Some of what I heard had to be the amps character at least 50%, Right?

3. I've heard some upper end M/L's powered by some big Krell amps. The system was lack luster until the power was turned up. The system was very uninvolving at low and moderate sound levels, the amps were not made for the timid, they would have to look elsewhere.

4. Again some amps sound fine until you crank them up, others sound fine but much better when you crank them up. This personality change in sound reproduction has many reasons and we cannot ignore them, we must be curious to learn more.

5. I may be using more power than I think, sure that is true if drinking. Drinking effects the inner ear which is why we get wobbly and our hearing diminishes. This is why drunks end up shouting in a loud bar. However I don't drink very much anymore so I'm using less power than before, plus I'm considerate of my wife being rocked out of the house. I'd bet that I'm crusing at one watt most of the time, and if I recall correctly my old M/L Aerius owners manual even mentions this in one place.

6. I have never read more disagreeable things from you Tonepub, not even when you said I had a $50 turntable or claimed that some people are just to lazy to have children. This one takes the prize, a real whopper with five major falsehoods. Keep up the good work man, it's entertaining.

 

[JMAUSGP]

Note: added matching numbers to comments as a key

My opinion differs on just about everything you have stated, and here is why:


6. I have never read more disagreeable things from you Tonepub, not even when you said I had a $50 turntable or claimed that some people are just to lazy to have children. This one takes the prize, a real whopper with five major falsehoods. Keep up the good work man, it's entertaining.

Kach22i,

I actually thought Jeff's comments were pretty innocuous and both general enough on some points and specific enough on others that they would be pretty hard to dispute.

Specific as in,

3. Even with the CLX, which is fairly efficient, even at moderate levels, those meters jump up in the 3-400 watt range on peaks.

This is exactly what I have found with my CLXs.

And general in terms,

4. An amplifier either sounds good or it doesn't, and it either has a lot of dynamic range or it doesn't.

Hard to dispute that.....at least I thought.

Sorry, I probably missed something, the post just left me a bit confused, which by the way is very, very easy to do

But in my defense, I am very easily entertained.

 

[Dan Osib]

The fact is you can never have too much power. Common sense will tell you you've got the volume level too high. The more power you've got the louder you can turn up your speakers before distortion can be heard. Bear in mind this is with a good quality amp in use though.

 

[Bernard]

1. I used a Radio Shack power meter (measured in watts) back in 1978 with my 25 watt Scott receiver and 12 woofer Audio Lab (Fisher) speakers, the 1-watt rule applied to that set-up. Not trying to impress anyone (or make you laugh), just being honest about my first hand experience.

I wonder if that RS meter was able to track peaks.

3. I've heard some upper end M/L's powered by some big Krell amps. The system was lack luster until the power was turned up. The system was very uninvolving at low and moderate sound levels, the amps were not made for the timid, they would have to look elsewhere.

Could it be that the acoustics of the room were such that you had to turn up the system to make it sound decent, i.e nothing to do with the amp ?

 

[kach22i]

I wonder if that RS meter was able to track peaks.
Could it be that the acoustics of the room were such that you had to turn up the system to make it sound decent, i.e nothing to do with the amp ?

Maybe the Rat Shack meters not could dance like the big ones on McIntosh gear, then again when viewing McIntosh gear meters even they rarely move, and then not all that much. If owners of such systems would like to post a video I'd love to watch it.

Again I'm talking normal listening levels, you can strain the system to get the peaks, but then you have to ask is it just for show?

The second question of acoustics might come into play on the Krell system because of room size and non-near field listening. It makes sense the room comes into play and also because that owner said he likes to play it loud, and all the time.

Looking back to near-field listening experiences playing at low and moderate levels, the lower sound pressure levels just fit their situation best. In those situations I'd bet it never went over a single watt.

If I were an electronics equipment engineer I'd talk about transformer windings and path lengths but I'm not, so I'll leave you to find and read what ever articles on the topic please you.

 

[babydoc]

Power requirements for MS Ascents

Like the title says, for a given speaker, how much power is "enough"? I currently am using Ascents and it seems most people give them somewhere around 300-400watts. Are people buying amps that are rated those numbers at 4 ohms or at 8 ohms?

It is interesting to me that ML recommends 200w for most of their speakers, but everyone invariably runs 2-3-4 times that number. Why? And at what point do you decide that you've got enough power going to the speaker?

I had Ascents some years ago and ran them initially with Innersound (Sanders) ESL amps in a bi-amped mode. The ESL amps were rated at 300 w/channel and drove these speakers without difficulty in my room (20x15x8) at a distance of 10 feet from the speakers. I then switched to a Pass Labs X350.5 amplier which runs as a Class A amp for the first 40 watts. Given the listening volume that I typically use, I rarely ever left Class A mode to A/B mode. While the ESL amps were fine, the Pass Labs was more musical to my ears, less dry, and created a better sound stage.

If it were all about "wattage" then we would all find some way to get behemoth amplifiers into our rooms and crank them to the max. One of the paradoxes in the amplifier-speaker interaction is that specifications do not consistently translate into better sound. I am currently using Pass Labs XA-100.5 monoblocs on CLXs. This amp, rated at only 100 watts per side is more than enough for these speakers and bested its predecessor the X-350.5 in its soundstage and musical presentation.

If you are considering new amplifiers for your Ascents, you should have the option of auditioning at least a few of different design and power and let your ears be your guide.

 

[Craig]

For get the WATTS Remember Current. Stability into 1 ohm CLASS A = clean power

What C.A.P. said.

I think current or amperage has a lot to do with an amp's power output and shouldn't be overlooked or it's importance underestimated. I just wish amp manufacturers would include this rating in addition to the wattage rating. From my experience, tube amps seem to be much more powerful than what their wattage spec eludes to.

I would assume that the manufacturers recommended power rating always applies to solid state gear and not tube gear. I have a pair of 600 watt mono amps that I use on the Summits but sometimes switch out to a 16 watt tube amp on the Summits. They each have their own strengths but both sound pretty darn good to me. Yet neither one comes close to the manufacturers power rating.

 

[DrJRapp]

Audio power is like money...you can live on a little, but you can never have too much!

 

[tonepub]

Couldn't agree more!

 

[Dominick22]

Maybe the Rat Shack meters not could dance like the big ones on McIntosh gear, then again when viewing McIntosh gear meters even they rarely move, and then not all that much. If owners of such systems would like to post a video I'd love to watch it.

I agree and would love to see this as well. A McIntosh needle video would be awesome and it would be cool to even watch the needle as the volume was increased!

A big 2nd motion from me!
Someone please do this for us!

Dominick

 

[Hocky]

I A / B / C'd the Carver TFM35 vs Rotel RB985 vs Mc252 tonight and definitely decided that wattage isn't everything. The carver is the most power with 350 at 4 and was definitely more dynamic than the other amps, but it was too harsh and tinny sounding. The Mc252 is VERY warm and mellow compared to the carver, but felt like it was lacking some texture after listening to the crispness of the carver. The Rotel actually was a great compromise between the two and was my choice after several songs, but it is the least powerful of the 3 with 200w at 4 (and being a 5 channel...) and it did struggle at dynamics points with high volume. I think I need to try to find a bigger wattage Rotel and see what I think.

 

[Jimna]

I agree and would love to see this as well. A McIntosh needle video would be awesome and it would be cool to even watch the needle as the volume was increased!

A big 2nd motion from me!
Someone please do this for us!

Dominick

here here, bring the video!