Watts are watts?


So it's been said that tube watts aren't the same as SS watts. This always struck me as nonsense, but I'm open to hearing what others think. In particular, I've been wanting to delve into tubes...whether in the form of a tube preamp or a tube or hybrid integrated. So....I'm sure that 90 watts would easily drive my Goldenear Tritons 1s. But how about if I decided to return to Maggies? I would normally never even consider that little power for Maggies...hence the question. Are tube watts really "stronger" than SS watts?
secretguy
No doubt that the amp/speaker pairing is important for good sound, and it's true that lower sensitivity speakers need more power than higher sensitivity speakers, however that's just part of the pairing issue. Generally, it's best to use higher impedance speakers with tube amps and speakers with benign characteristics of their impedance/phase angle relationship. You may find a combination that works OK for you, but IMHO, I don't consider the speakers mentioned to be very "tube friendly".
The thought is that when driven in distortion, clipping, that tubes will generate more pleasant sounding harmonic components than solid state amp.  More 2nd and 3rd compared to 7th and 11th overtones.  Ideally, you shouldn't be driving any amp into clipping.
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Watts are watts except when there is some dynamic headroom built in, let’s say 3dB.
Then watts are not watts.
Watts are watts, except when it comes to my preference for tubes over solid state. I found, after many years of having both types and from different manufacturers, that tubes are what makes my music brain happy. I prefer the envelope around the midrange far more with tubed phono, pre and power amplifiers.
I drove Maggies for a while with a 150 watt NAD...it never broke a sweat. On the other hand, a 125 watt HK crapped the bed.
For the most part, when I've had Maggies, I had at least 225/channel.
Are tube watts really "stronger" than SS watts?
Of course not, the differences lie in how the two types of amps operate and, thereby, the application. Tubes are current source devices whereas SS amps are voltage source devices. What this means: IDEALLY a SS amp will maintain a fixed voltage whatever the load resistance (or other parametres). Accordingly, the IDEAL current source will provide a constant current to a load despite changes, in load resistance, etc. As you know speakers are variable loads (depending upon frequency etc.) so the inherent characteristics of each circuit will invariably affect the audible result when driving any given speaker.

As mentioned above, tubes are generally happy with high impedance speakers, full-range speaker units (due to their impedance & phase characteristics that are often countered by the tube amp’s output circuit characteristics).

Most mainstream speakers have been designed to operate with voltage circuits—however, this doesn’t mean you do not get excellent results with tubes in many cases; there are even tube circuits without output transformers that offer characteristics of both designs... (one of Atmasphere's team is an Agoner and very knowledgeable on this subject-not surprisingly!). Regards
Back in the mid-70’s, I considered both Maggie’s and DQ-10’s. Both present inefficient loads for amps. Ended up getting the DQ-10’s, based largely on sonic preference. (I might not have auditioned the Maggie’s in the best room—possibly being too close to a rear wall.) I used a Dynaco ST-150 (75WPC transistor amp) and then GAS SOA (80WPC solid state unit) for the DQ-10’s. Neither one likely had sufficient power to make the DQ-10’s sing.
You might consider a New York Audio Labs (NYAL) 300. Hybrid amp (4 tube front end, MOSFET output stage) of 150 WPC. Designed by George Kaye. I have the smaller version (NYAL 150) - 75 WPC. Excellent sounding amps, combing the virtues of both tube and SS circuits! And the tube front end allows for tube rolling to alter the sonic characteristics!
@celander: I still have a pair of DQ10's and a Son of Ampzilla (actually 2 of them!). I consider that a good combination. But you may just like to listen at higher SPL's than me, in a larger room!
Interesting stuff. Thanks for all the knowledge. I guess I should concentrate on getting something that works well with the Tritons that I have now, and worry about dealing with Maggies later , IF I do go back to them. (Actually, my Anthem integrated kills with Maggies. I just keep wondering what tubes would do for the Tritons).


@roberjerman yes, they were set up in a big room. How are your woofer surrounds? I got another set of DQ-10’s off eBay a few years back. The woofers were the first things to go. The legacy company was (is?) still in business, so I was able to get new woofers. 
What’s missing in watts is the output impedance of the amplifiers. This can behave in positive or negative ways depending on the speaker and it’s design.

Also, its important to understand how little watts have to do with loudness. Relatively. Doubling the power increases loudness only by 3 db. To get double the loudness, you need 10x the power. So the difference between 90 watts and 150 watts is less than 3 dB.

If you want to do the math yourself: 

change in dB = 10 x log ( powerA / powerB )


Best,

E
Good point! It’s the efficiency of the speakers. That’s why you only need 3 watts or whatever to drive horn speakers. Hopefully tube watts.
I powered my magnepan IIIa speakers with an Audio Research D125 (115 w/ch) tube amp for years with great results!

They played clear and very loud.
IMO, there’s no substitute for class A bias output, whether it be tubes or SS.  Think of a class b amp as a dragster idling at the start line and a class a biased amp reved up to 8K rpm. The flag drops. The idling car driver, then puts the throttle to the floor and can go quite fast, however, the car that was reved up to 8K rpm simply drops the clutch and is gone in a flash.  May be a weird comparison, but the class a amp is always wide open sitting there just waiting for a signal.  It’s very quick.  No pause or sluggishness to reproduce that cymbal, snare crack or bass drum.  You can heat your room with them in the winter, but oh what sound.
Actually I love the analogy, being that I'm a huge NHRA fan!
OTOH, I can't say I've ever experienced "sluggishness" in an amp. I think too many hears of being in the middle of live music has dulled my golden ears.
Great thread.....I recently purchased a set of vintage DQ 10's and am considering taking the plunge into some 'mega wattage'.  To me, they sound amazing with my Yammy SS but I remember still a friends Phase Linear 400 and KLH speakers from the 70's.  Wow......  And great anaolgy by @handymann !

I'm an electronics technician, and on paper watts is watts but according to my listening tests tube watts are more powerful, and for me, I leave it at that.
I have no engineering degree but I understand that speaking of speakers it is an impedance curve, that can be complicated. How do you really match an amp unless you customize it ? Aside from both being built by the same company, like Gryphon or MBL. Trying even dozens of different amps would unlikely get you there, especially if you want a near perfect match.
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