Which watts are the right watts in SS amps?


Hello Sports Fans!

More than a few people over the years on these pages have said only those SS amps which double down in output power as impedance drops are truly special or worthy amps. Eg., 200 @ 8ohms; 400 @ 4 ohms; 800 @ 2 ohms; etc.

Not every SS amp made does this trick. Some very expensive ones don’t quite get to twice their 8 ohm rated power when impedance halves to four ohms. BAT, darTZeel, Wells, and Ypsalon to name just a few.

An amps ‘‘soul’’ or it’s ‘voice’ is the main reason why I would opt in on choosing an amp initially and keeping it. Simultaneously , I’d consider its power and the demands of what ever speakers may be intended to be run with it or them.

I’ve heard, 80% of the music we are listening to is made in the first 20wpc! I’m sure there’s some wisdom in there somewhere as many SS amps running AB, are biased to class A Only for a small portion of the total output EX. 10 – 60 wpc of 150 or 250 wpc.

After all, any amps true output levels are a complete mystery when anyone is listening to music anyhow.

I suspect, not being able to actually measure true power consumption, the vast majority of listening sessions revolve around 60wpc or so being at hand with traditional modern reasonably efficient speakers.

Sure, there are those speakers which don’t fit into the traditional loudspeaker power needs mold such as panels or electrostats, and this ain’t about them.

The possibility of clipping a driver is about the only facet in amp to speaker matching which gives a person pause while pondering this or that amplifier.

I feel there is more to how good an amp is than its ability tou double output power with 50% drops in speaker impedance.

However, speakers are demanding more power lately. Many are coming out of the gates with 4 ohm ‘nominal’ IMPs which lower with fluctuations in frequency. Add in larger motors on larger drivers, multiple driver arrays, and on paper these SOTA speakers appear to need more power.

IMHO It is this note which introduces great concern.

I’ve read every article I can find on Vienna Acoustics Music. Each one says give them lots of watts for them to excel.

Many times good sounding speakers I’ve owned sounded better with more power, albeit from arguably a better amp.

I tend to believe having more than an adequate amount of cap power is indeed integral. … naturally the size and type of transformers in play possess a strong vote for an amps ability to successfully mate with speakers.

Controlling a driver’s ability to stop and restart is as well a key to great sound and only strong amplifiers can manage this feat. Usually this gets attributed to ‘damping’ factor, but damping as I read it is more a shadow than a tangible real world figure as it depends on numerous factors. Speaker cable length alone can alter damping factors.

A very good argument exists about those mega watt amps voices. Each 500 or 600 wpc amp or amps, I’ve heard have had stellar voices too, not merely more watts.

So is it predominately these mega watt power house amps souls or their capacities that fuels the speakers presentation?

Would you buy an ‘uber expensive’ amp based more on its voice or soul, than on its ability to output loads of watts, even if you feel the amp may be somewhat under powered for the application?

Choosing this latter option also saves one money as the more powerful amps do cost more than their lower outputting siblings.

Please, share your experiences if possible.

Tanks muchly!

blindjim

Showing 5 responses by atmasphere

Almost invariably I’ve noticed in friends outfits, that some were noticeably IMO underpowered as the sound in the mids and bottom end was well, I’ll go with ‘soft’’ or fuzzy. Not to the point of most people’s notice, but to my own appraisal. Again, I came to this revelation by moving up in amp power rating and build quality as time passed so it was actually an incidental observation. Albeit, a valid observation no less.
@blindjim that description really sounds like the amp clipping- all bets are off at that point.
are you nutz even suggesting any of your amps would compete with the Gryphon I mentioned on a speaker such as the Wilson Alexia, or others even with similar hard varying loads.
Funny about that- John Giolas had our amps for years- Soundstage thought it was the best system they had ever heard. Going back decades, our amps have worked pretty well on the Wilson speakers. The newer speakers are lower impedance, but in practice retain the Wilson quality of otherwise being easy to drive. And as you know, if its merely an impedance issue, the ZEROs are always there to help any amplifier out.

I rather doubt that I'll get the opportunity to hear our amps against the Gryphons while driving Wilsons, but it would be fun.

In other words easy to drive speakers that are as close as possible to a pure resistive load, which Ralph there are not many good ones, Magies come to mind, not much else of worth, that why you push the Zero Autoformer.
This statement is false. The most popular speaker with our M-60 was for many years the Merlin VSM which is a 6 ohm non-resistive load. I don't push the ZEROs because of the Maggies (our larger amps have no troubles with them; but many people seem to like the idea of a 60 watt tube amp on Maggies **that** is when I push the ZEROs for Maggies owners), I push them as problem solvers for tube and solid state amps. Its a much larger picture than you want to paint: if it were really that small as you suggest we'd not have been able to be in business for 41 years...
Gryphon top of the line amps will blow to hell all the tubes in all the tube amps Ralph has ever touched. Along with all Classic Audio speakers and Technics DJ turntables. Nothing does power and current like big Gryphons.
The Gryphon amps are excellent! I was in the Gryphon room at CES years ago and witnessed a reviewer threatening the owner of Gryphon that if he didn't give the amp to him for free, it would be a bad review. The Gryphon owner had more ethics than that and it didn't go well; that reviewer pretty well shut down Gryphon sales in the US for over a decade. I admired them as they did amazing extrusions on their heatsinks, supported balanced operation properly and generally built an extremely high quality product.

Not sure how any amplifier blows a set of speakers and a turntable 'all to hell though'- that part of your statement seems nonsensical. Your statement about power **and** current does not make sense either and here's why: if an amp can make a given power into a given load (say 300 watts into 2 ohms) we can determine the current easily enough:

First, Ohm's Law relates voltage, current and resistance R=V/C

From that the power formula derives: 1 watt is equal to 1 volt times 1 amp.

If you state it in terms of resistance

The power formula is Power = (current squared) times resistance.

So plugging in the values: 300 = (current squared) times 2

solving for current squared we get 150, the square root of that is 12.25 amps.

From this I hope that you can see that it does not matter what kind of amp makes that power- the current will be the same; power (wattage) is the result of current and voltage together- current cannot exist without voltage.
The correct answer George, was ’no’: if two amps are making the same power into a given load, then the current is exactly the same. It was a trick question in a way. The trick was knowing Ohm’s law.

Now in this case:
Given the Magico’s impedance v phase graph, the amp with "ample current" will stay flatter in frequency response than the one that is "current challenged" especially at 50hz where impedance and -phase is at it’s worst.
- if the amp can make the power into the worst of the load then how much power will it make into loads that are not as difficult? The answer is ’less’.

So we can see that if a tube amp can make the power needed, it does not have to be a perfect voltage source to still get flat frequency response, as good as any solid state. Its simply has to be good enough to do that.

There is an issue here, the harder you make the amp work, the more distortion it will make. You can see this in the distortion vs frequency specs of all amplifiers. The distortion is audible too- in the form of increased brightness and hardness, caused by higher ordered harmonics to which the ear is keenly sensitive, as it uses them to sense sound pressure.

So a powerhouse amp might be able to drive some insane load, but there isn’t a reason related to high quality sound reproduction to do so. If you want the amp to strut its best, an easy load will have it making less distortion- it will sound more like music.

Regarding our amps, they were designed with intention to work with speakers that do not require feedback of the amp; this is done because a speaker that **does** require that of the amp will inherently never sound like real music- it will always sound like a hifi- maybe a really good one, but still a hifi instead of real music. See Norman Crowhurst, you can download his books from Pete Millet's website http://www.tubebooks.org/technical_books_online.htm

But you will not get the best from them until you hear it driven properly with a solid state amp that can drive this sort of load with current.
 
George, maybe you can clear something up because as far as I know, the above statement is outright false. If the amp is making a given power into the load of least impedance, is the current going to be higher with a high current amp as opposed to one that has less current?

BTW, this is a yes or no question...
The way each amp handled the paired speakers was fairly evident too in that the sound was tight. Quick. Clean.

Harmonics and dynamics differ from one setup to another but the speed and pacing were taught and pronounced. IMO those attributes are the result of power.
Actually that is the result of bandwidth. Output impedance can play a role in how 'tight' the bass is (but quite often, 'tight' also implies that the speaker is over-damped in the bass; while that gets you 'tight' bass it also means there is a loss of definition as the woofer is not allowed to move as far as it should).

The main thing you are looking for with your speakers is the ability of the amp to act as a voltage source. This is the idea that the amp can put out the same voltage regardless of the load impedance.

The thing is, the amp does not have to double power as impedance is cut in half at **full power**. This is why the CJ tube amp worked on the speakers- it does not have a lot of so-called 'current' yet could do the job just fine.

IOW, there are a lot more amps available to you that will do the job.