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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
georgehifi's avatar
georgehifi
10,312 posts
 
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



erik_squires
16,407 posts
 
It's not a matter of the first few watts. It is a matter of how the electrical frequency response changes based on the speaker.

A perfect amplifier has a flat electrical FR, regardless of the speaker. A weak amp may have it's FR adulterated by the speaker crossover, and that happens even before 1 watt.

Here is a measurements page from a Prima Luna design, to see what I mean:

https://www.stereophile.com/content/primaluna-prologue-premium-power-amplifier-measurements

You don't need an ideal amplifier to have good sound. Goodness knows most tube amplifiers barely meet this requirement, but it is a good indicator of the current drive, and guts of the amp.

Nelson Pass does make a related, but not the same, point about the first watt being most important. But he's talking about noise and distortion. He, rightfully, states that Signal to Noise at 1 watt is a far more important gauge of sound quality than Signal to Noise at full power (which we never spend time listening to).

Best,

E
czarivey
5,946 posts
 
Hmmm lemme guess:
In SS amps the "right" watts are perhaps ones delivered or possible to deliver from Right channel.

Case solved?
ghosthouse's avatar
ghosthouse
4,319 posts
 
Picking up on Erik Squires’ reference to Nelson Pass....

I recently purchased a First Watt F7 amp. It generates 20 watts into 8 ohms and 30 watts into 4 ohms, so it doesn’t "double down". On a couple different levels it seems to embody "the less is more principle". I also think it shows not all watts are equally "capable". I’m mainly using it with moderately efficient Silverline Prelude Plus speakers (nominal 92 db sensitivity). Sound quality is extraordinary with the Preludes and was absolutely astonishing when the F7 was used for a short time with 87 db sens. Totem Forests. It won’t peel paint but the sound produced is "to die for".

At the risk of being accused of exaggeration, listening with it is like going from B&W TV to color, if you will pardon the non-audio(phile) analogy. And this by comparison to many different higher power amps including tube mono blocks and, more recently, Hegel H200 and Merrill Audio Taranis (both still part of "the fleet").

In the interest of full-disclosure, while the sound with the Forests was absolutely magical (the best they’ve ever sounded) concerns about yielding to temptation and pushing the volume into clipping territory and damaging a tweeter led me to discontinue that experiment. SPL readings of upper 70s db at 10 feet diagonal from the speaker (C weighting; Slow response) were easily achieved beforehand with no sign of strain - very satisfying levels for late night listening. With the more sensitive Preludes, low to mid 80 db peak SPL are regularly registered at the same 10 foot listening position. Completely satisfying levels for the kind of listening I do.

So, in reply to Blindjim’s question, "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?" The answer is "yes"...except for the uber expensive part.  The F7 lists for $3000.

(FWIW - I believe NP credits Dick Olsher with "the first watt is the most important watt" comment).

For more info:
http://www.firstwatt.com/pdf/prod_f7_man.pdf
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