Tube vs. Solid State-Basic Question


So here I am with my first all tube amp, the Manley Stingray II. While I wait for my Merlin TSM-XMr's to be delivered I've got the Stingray connected to a pair of Definitive Technology BP7004 towers in my theater room. I also ran them with a few other amps....testing them with a Cambridge 550A amp with 60 watts. I was able to play the speakers with the Cambridge well enough, but on tough passages at higher than medium volume the sound got congested and even distorted above that level.

So now I connect the new Stingray, switch to Triode-Mode (just 18 watts) and I get equal volume (or more) with beautiful sound, dynamics and imaging....and that's 18 watts in triode mode! The extra watts of the Cambridge did not appear to be of any use. What's up with that?

So....can some folks more educated on tubes explain to me....like I'm a two year old how the low powered Stingray plays so well with so little power?

Next up was to switch out of the triode mode and get the full 35-40 watts from the Manley which could drive the speakers very loud in my fairly large theater room. While I'm VERY happy with the Manley Stingray, I'm also a bit confused at the power the thing seems to have in spite of it's lower power. In fact my fat Denon receiver (110 watts) cannot keep up with the Stingray.

All comments welcome!

Bob
robbob
there was a very long thread on this phenomenon here:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1267984978&&&/Power-output-of-tube-amps-compared-to-so

Watts is watts, but amplifier and power supply design can allow a certain amount of headroom beyond the stated power specification.
I had the same experience with a 30 watt ARS Sonum Filarmonia (great match for your Merlins btw). It completely out muscled an expensive and modded 200 watt AV receiver.
What you have with Manley is simply an good match with your speakers, cos this is the key. The rest is just the rest, so, enjoy!
Tube amps offer an wonderful option and that's the tube tonality, which you can change with tube rolling, while SS amps are pretty much done, unless your pre-amp or other pre-equipment also a tube based one that can have some influence on SS power or integrated amps.
For example my CD player output have 2x ECC82 valves and if I roll them it creates some tonality change at the end, such as better clarity, extension or bass. Each tube brand have their own sound sig, where Mullards are more warm with great mids, but can loose some detail. But TUNG SOLS are very rich, but not warm, having great extension and tighter bass. All these small things make the final picture bit differently and that's why tubes are very fun, however in your situation can be quite expensive as well, cos there are so many of them in Manley:)
There are some technical things involved to, but hoping that other members can tell you more about that part.
Other than that, congrats and enjoy!
I was told by a highly respected tube / ss amp manufacturer that what you are hearing has to do with the higher plate voltages that tube amps run with ..... Simplified explaination for sure but it is basically in the design of tube versus ss amplifiers ....
Tube watts do sound and feel much meatier than solid state watts. Match to your speaker is important of course.
Art
I have one additional comment to add in addition to what's been offered already. It is my understanding that when a tube amp clips, meaning the volume and complexity of a passage overwhelm the tube amps ability to adequately drive the sound, the clipping is not objectionable to the human ear. However when SS clips it is very objectionable. So even if the Manley were to be overwhelmed you may no be able to identify it.
Massive power supplies help. How much does the Manley weight vs the Cambridge?

Also, when you look at specs, you will see dynamic headroom. Some amps can put out peaks anywhere from 0db to 3db to 6db or more. What that means is that some amps rated at 32 watts will sound lousy as soon as they try to push 33 watts, while other amps with let's say 3db of dynamic headroom can handle 64 watt peaks without any noticeable loss of sound quality. Many times you are only playing at 5 watts but may need 10 times that for peaks in the music.
The thing I always go back to is what an "old timer" told me..... that unless there is lethal voltage under the hood, there wouldn't be music. Where do you get lethal voltage....tubes. O sure, I like some SS designs and sound, but tubes usually consistently sound musical. SS is hit and miss. The damping factor is so high with many SS designs they simply don't let the woofer move enough and put the brakes on before the harmonic structure has completely formed, giving a thumpy popping sound in the bass so all the notes sound the same. I don't call that music. However, there are some SS designs very musical like Pass, Bryston, Halcro, Levinson, Ayre, and others, but for the money, tubes gets it done. The key thing mentined before is the matching with your speakers, this includes the damping factor, efficency, etc. A 30wpc tube amp will not cut the job on Maggie 3.6 panels in a big room. You need some real horsepower say more than 500wpc. A speaker with a sensitivity of greater than 95 will do well with many amps at 20wpc or more. Trust your ears, and match amp with your speakers and enjoy the music. Speakers with a sensitivity of 100 plus dB will do well with half of a watt and 10wpc is overkill. It is also about the sensitivity.....Jallen
Well....I bought the Stingray II because Bobby suggested it as a great pick for my soon to arrive Merlin TSM-MXr's. Of course quite a few chimed in to say the Stingray/Merlin pairing was made in heaven, but I just did not expect the Stingray to sound so good with a pair of Def Tech speakers bought at Best Buy!

That's not a knock on the Def Tech BP7004's either. They're quite good, but were bought for home theater as the main course. The Stingray has them singing.

Bob
Welcome to the wonderful world of tubes !!
Enjoy your new system, love the nusic, and have fun !!
Happy Listening !
I found the Stingray to be exceptionally powerful for its rated output.

They are just well made amps enjoy!

Also enjoy the Merlins...
I also think you are hearing the very loose use of power specs in a receiver rated at 110 watts in your denon vs the Manley.
Also when a tube amp does clip the result is less anoying to the ear than a solid state clip;which can destroy a speaker in a heartbeat.
Also since Bobby recommended the Manley he would be most familiar with system matching of the Merlins;which you are going to really enjoy.
I think you may see a post from Atmasphere on this question
and if Ralph does post pay attention to his response as he is one of the best designers in the audio industry and also a audiophile.
Enjoy the new world of tubes and if you have any questions just post and you will get excellant advice the people in the hobby and business!!!
Most good quality amps specify output as RMS watts over a particular frequency range at particular distortion rates with all channels driven simultaneously. It used to be common for mass marketed AVRs to use a less stringent specification of wattage, I think they may have called it something like music output, but I don't recall. So, watts may not be watts in specifications depending on how they're defined. The wattage available for a 1 kHz signal one channel at a time will be very different than that for 10-100,000 Hz all channels driven simultaneously. Then there is distortion, which typically rises rapidly above the level of the output specification. And then there's gain: In the days when I was concerned with tube amps, an MC 60 could deliver its 60 watts with a 0.5 volt input, whereas a Dynaco required a 1.5 volt input to deliver 60 watts. Wattage output is not the same as gain, and what amps provide is gain.

db
i play bass guitar & love tubed amps. my '64 gold fender bassman used 6L6GC's. love my ss gallien-krueger, it emulates tubes. my 44wrms fender worked onstage at dances w/up to 1200 people. i never miked thru house systems. my g-k has 700wrms +50wrms thru a bi-amped horn. told 5x the rms power needed from ss compared to tubes for similar volume, tho unsure of actual ratio.
Since the Def Tech's have a self-powered woofer, they don't require much in the way of wattage to sound their best, as you are only driving the the tweeter and midrange. No doubt you prefer the seetwer midrange sound of the Manley tube amp and it has sufficient power for the Def Tech's with their self-powered woofage.

Greg
Kingmacaw, interesting antic dote. I too experienced low wattage tube power using Marantz 8B's and DIY JBL 4530 15" Scoops in the early 60's. The system was a monster to transport and setup but it was way louder than anything commercially available. Then came the SS acoustic 360/361 which was difficult to use in small venues which lead to the SVT. The Ampeg was a slug with a great amplifier section and a pedestrian preamplifier and cabinet. I find there popularity today truly comical. The 200 watt acoustic was way louder with amazingly flexible tonal palette. I found the big difference was horns Vs. flat baffled cabinets.

The 360/361 has been creatively upgraded (not a reissue) by the original designer, Russ Allee. If you ever have a chance to play trough one don't pass it up.