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
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.

To put it more simply:

No amp will exactly double all the way, anyone who advertises this is stretching the truth.
Ones that can come close to doubling (usually good bi-polar output amps) all the way to 2ohms, can push good current into hard to drive speaker EG: most Wilsons especially Alexia ( .9ohm epdr in the bass) and many other brands.

This is however not an indication of good sound quality, but your half the way there with a "very" important part of the equation to get it, but your half the way there with a very important part of the equation to get it. It's up to you then to sort these out with best one sound wise, as you taken care of the drive (current) factor. 

Cheers George
If a speaker is underpowered it won't perform at its best and may clip.  You need to find an amp that outputs the power your speaker needs and has soul.
This might help:  http://chuckhawks.com/speaker_spl_amp_power.htm 

Sorry it's not the full picture, nowhere does he talk about current into low impedance's, he's only interested in watts and spl.
He's only half the way there by talking about efficiency, not impedance loading and difficulty to drive into low impedance loads.

Cheers George 
Thanks all. Really.

The concern is how do you determine what amount of power is appropriate in advance?

And or, at what point should you become concerned with an amps power rating, if you know the speakers numbers, placement, and distance to the LP ?

As I understand it, on paper, a 91db sensitive speaker should develop 91db SPL at one meter (about 40 inches) with one full watt without room reinforcement.

At 2M with one watt the same speaker SPL halves so power must double. Add one more meter, and at 3m the power must double again to yield the same SPL developed at one meter.

Thus… at 3M a 91db sens speaker needs 4 watts. At one set freq. more if most of the bandwidth is being engaged.

Yes?   No?

In my own case, the LP should never be more than 10 – 12 feet away from the front baffles.

My guess is 200wpc is plenty for generating aforementioned SPLs. Even a 120wpc amp would work for that matter. I think.

Every speaker I’ve looked into with interest have sens of 88db or higher. Most are 89 – 91db.

Using an older Radio Shak digital spl meter on speakers of 93db from a distance of 9ft from their baffles setting the meter to average peaks, a 93 to 96DB range was enormously loud. Irritatingly loud IMO. Maybe one song only kind of loud if I felt the need to Pour Some sugar on it, or dig a Whole Lot Of Rosie! Once.

So clipping looks like the bigger deal. That and providing the speakers enough power to keep the drivers on pace firmly.

Amps I’m liking a lot in no real order are Gryphon coliseum ypsalon Alieus, Constellation Imagine series, PSA BHK monos, Bermister (not the biggest one) BAT 655, and Master Sound classic

I might well be worrying about nothing. Although at these prices worry seems a necessary evil.