How many Tube watts do I need?

Ericus Rex · « **Reply #20 on:** 20 Dec 2010, 01:51 am »

I, and others on this forum, find that watt for watt tube amps seem to be louder than ss amps. Engineering types have told me that tubes are able to deliver transient peaks better than transistors and this could be the reason. I personally don't know how or why it seems that way...it just does! So I don't consider 40 watts of ss power as equal to 40 watts of tube power as other members suggest...at least not in practice.

TheChairGuy · « **Reply #21 on:** 20 Dec 2010, 02:29 am »

Well, I heard a different reason why tube watts seem BIGGER than solid state watts

I've read it's because the breakup at it's peak output is more gradual, maybe even euphonic. So, SS watts kinda' drop off a cliff more suddenly...while tube amps compress and distort more, but it's easier on the ears to handle at and after that limit

Def not an engineer or theorist on this...just heard the story on watts differently than you have.

John

Ericus Rex · « **Reply #22 on:** 20 Dec 2010, 01:21 pm »

Maybe both reasons are correct, John!

JLM · « **Reply #23 on:** 20 Dec 2010, 03:33 pm »

As eluded to above, typical tube amps watt for watt have beefier power supplies than solid state amps, which helps them cleanly handle peak power. Some of this relates back to the specification games some vendors play to look good on paper. (Unfortunately most specifications are still based on 50 year old standardized methods are now considered crude and largely pointless, but the unscrupulous use to deceive the unwary.)

Another reason is that tubes clip (meaning exceed their useful power limit) "softer" (a term borrowed from NAD) than solid state so they are less likely to blow drivers. The term "clip" relates to what a simple single frequency waveform looks like on an oscilloscope when the circuit being tested is overloaded. The top and bottom of the sine wave is suddenly flattened out at the limit of the circuit. Your speaker tries to follow the same waveform, but can't suddenly stop in mid-motion. Something has got to give, so the energy previously being used to move the cone/dome is released as heat that can melt voice coils. Note that the circuits themselves can also be damaged from the heat produced by clipping. Solid state tends to flatten (clip) suddenly where tubes "round off" that sudden motion, which tends to result in less damage and abrupt distortion.

A third reason tube watts may seem louder is the lack of damping compared to solid state. Damping relates to how well the driver motion is controlled by the amp. Poor damping is described as loose or flabby, especially in bass. Newer tube designs tend to have better damping while some solid state are so tight they can make for a sterile, even constipated sound. Regardless, less damping will make the sound seem louder and this points to one of the most important synergy issues in audio.

DTB300 · « **Reply #24 on:** 21 Dec 2010, 01:19 am »

Quote from: Ericus Rex on 20 Dec 2010, 01:51 am

I, and others on this forum, find that watt for watt tube amps seem to be louder than ss amps. Engineering types have told me that tubes are able to deliver transient peaks better than transistors and this could be the reason. I personally don't know how or why it seems that way...it just does! So I don't consider 40 watts of ss power as equal to 40 watts of tube power as other members suggest...at least not in practice.

So lets say we play a 1k test tone just so we can set a volume level to test two amp types. We are not looking at sound quality at this point in time, just a test to see if one amp plays "LOUDER" - not a "SEEMS LIKE" it plays louder. Does one play louder or not? If not, it is just marketing BS to make you think you are getting more for your $$$$.

Okay: We have our pre amp all set, our source all set, our speakers all set. We then play the tone and get a electrical reading out the back of the amp speaker terminals. Let us start with the SS amp first. We now record our voltage reading, and we might as well record amperage while we are at it. Now we measure the SPL from the speaker at 1 Meter with our SPL meter mounted on a tripod so it to stays in the exact same place. Now it is time to switch to the Tube Amp, and setup everything the same as before. Time to measure: Will there be an increase in SPL's with the Tube Amp in place?

Should speakers change SPL levels even when fed the same amount of electrical properties? They shouldn't right? Maybe it is just a preference of the type of sound one is looking for and not really SPL measurements.

If this seems all rather absurd, it is. It is all about the sound and not word play....

Tyson · « **Reply #25 on:** 21 Dec 2010, 02:49 am »

Or, you could actually listen to a speaker playing music instead of tones. People are saying they notice a difference between tube amps and ss amps of similar power ratings. An engineer plays around with test tones, hurumphs, and dismisses such absurdity. A scientist (on the other hand) notices that perceptual phenomena don't align between the 2 amp types, they ask "why?", and start investigating. Such is the difference between an engineer and a scientist....

eclein · « **Reply #26 on:** 21 Dec 2010, 03:17 am »

My DAC has a tube in it, when I first got it the sound changed and I refer to the sound as "golden" like. Its like when cartoonists draw a trunk full of gold and jewels and they always draw that yellow shimmering outline signifying the brilliance that's in the chest, that is how I would best describe tube sound. That sound type hooked me in bigtime, I'll always have some tubes somewhere in my rig that's why I want to try a tube amp.

Ericus Rex · « **Reply #27 on:** 21 Dec 2010, 01:04 pm »

Quote from: DTB300 on 21 Dec 2010, 01:19 am

So lets say we play a 1k test tone just so we can set a volume level to test two amp types. We are not looking at sound quality at this point in time, just a test to see if one amp plays "LOUDER" - not a "SEEMS LIKE" it plays louder. Does one play louder or not? If not, it is just marketing BS to make you think you are getting more for your $$$$.

Okay: We have our pre amp all set, our source all set, our speakers all set. We then play the tone and get a electrical reading out the back of the amp speaker terminals. Let us start with the SS amp first. We now record our voltage reading, and we might as well record amperage while we are at it. Now we measure the SPL from the speaker at 1 Meter with our SPL meter mounted on a tripod so it to stays in the exact same place. Now it is time to switch to the Tube Amp, and setup everything the same as before. Time to measure: Will there be an increase in SPL's with the Tube Amp in place?

Should speakers change SPL levels even when fed the same amount of electrical properties? They shouldn't right? Maybe it is just a preference of the type of sound one is looking for and not really SPL measurements.

If this seems all rather absurd, it is. It is all about the sound and not word play....

If what makes tubes seem louder is actually the delivery of the transients (attacks of notes) then a test tone will show no difference between the two. Same with white noise and an SPL meter. A watt is a watt is a watt. Tubes don't make extra watts out of nothing. However, tubes and ss do sound different (if you disagree with that statement you shouldn't be commenting on this thread at all) and the sonic signatures of tubes (vs. ss) give them a perception of sounding louder than equal ss watts. And if John's reasoning is correct about the softer clipping than you could say that tubes actually do go louder before becoming unbearably clipped.

JLM · « **Reply #28 on:** 21 Dec 2010, 01:28 pm »

Quote from: Tyson on 21 Dec 2010, 02:49 am

... Such is the difference between an engineer and a scientist....

I'm an engineer and take offense. IMO an engineer artfully applies science. I believe what you're describing could be termed a "technocrat".

Few realize that true science is nothing more than practicing the scientific method of observation, questioning postulating, objectively testing, and drawing logical conclusions. In a society that has benefitted from science (engineering really) it has replaced the understanding of the method for simple worship of the end gains. And so "science" is taught as acceptance of scientific "truths" without questioning.

DTB300 · « **Reply #29 on:** 21 Dec 2010, 02:42 pm »

Quote from: Ericus Rex on 21 Dec 2010, 01:04 pm

If what makes tubes seem louder is actually the delivery of the transients (attacks of notes) then a test tone will show no difference between the two. Same with white noise and an SPL meter. A watt is a watt is a watt. Tubes don't make extra watts out of nothing. However, tubes and ss do sound different (if you disagree with that statement you shouldn't be commenting on this thread at all) and the sonic signatures of tubes (vs. ss) give them a perception of sounding louder than equal ss watts. And if John's reasoning is correct about the softer clipping than you could say that tubes actually do go louder before becoming unbearably clipped.

Yes, tubes do CLIP differently than Transistors. No matter what the sound, I NEVER want to clip an amp while listening to music. Distortion is distortion, no matter if someone says it is "better" distortion - another BS term to sell stuff. If someone wants to buy a Tube amp to clip - power (or lack thereof) to them. Now for a guitar player clipping their amps...that is something totally different....

The sonic signature makes an amp sound better MUSICALLY, not louder. The perception of "louder is better" falls right in line with Super Sizing Mentality in this world.

I do not think a blanket statement of Tube Amps can deliver transients better than SS is again more marketing stuff. Both can do it well, both can really suck at it.

Tube amps and SS amps CAN sound very different, but I have heard as many crappy sounding Tube Amps as I have heard crappy sounding SS amps.

All of this should really be about, what type of sound do you like in your rig in your home? If you like Tubes, buy tubes, if you like SS, buy SS. Buy as much power as you can afford for the amp which sounds the best. Do not worry what ANYONE thinks about your purchase or setup, it is your own rig in your home and "F" anyone who will say otherwise. It is about YOU and the MUSIC, not anyone else.

So saying that something seems (edited out for Ericus Rex)....well...here are some examples:

1.   It SEEMS like I won the Lottery, but my bank account is still low
2.   It SEEMS like I drive a Ferrari, but it still says Hyundai on the side
3.   It SEEMS like I wear a Rolex but the face still says Timex
4.   It SEEMS like I am wearing pants, but it sure is drafty in here

Ericus Rex · « **Reply #30 on:** 21 Dec 2010, 04:39 pm »

We all just said they "seem louder". "Seem better" is your own misinterpretation of the above posts. "Louder is better" is again your quote, not mine.

TheChairGuy · « **Reply #31 on:** 21 Dec 2010, 05:57 pm »

Quote from: JLM on 21 Dec 2010, 01:28 pm

I'm an engineer and take offense. IMO an engineer artfully applies science.

Having worked with many engineers of various kinds in my profession and as hobbyist....I find most Engineers doggedly apply science to tasks; artful is not normally an apt description for what they do.

But, neither would I want most Engineers to apply art to science...they are there to (hopefully) take often hair-brained conceptual ideas from more creative types to reality.

I have the same expectations of 'artistry' from an Engineer as I would from any Accountant...that is, not at all.

Different folks with different strokes.....it all fits like a wonderful puzzle in the end

John

rollo · « **Reply #32 on:** 21 Dec 2010, 06:58 pm »

If you would like to borrow an Audio Research Classic 60 to check out a tubed amp come and get it. 60 watts of triode bliss. I am in NYC. Compared to an older Bryston 4B when driving Maggie 3As the AR had better dynamics and played just as loud. Go figure.
With the Pipedream speakers my SET [ 18w] plays the same as the AR. I can detect no difference other than character of sound.

charles

Quiet Earth · « **Reply #33 on:** 21 Dec 2010, 07:54 pm »

Quote from: eclein on 19 Dec 2010, 09:25 pm

the first amp I was lusting after was like 8 Watts, an expensive 8 watts and sounds like not enough...

It sounds like not enough (watts) when you listen to the amplifier in your room with your speakers? Or it sounds like not enough because so many people are convinced that you need to have a minimum number of watts based on some speaker data that they read? Listen for yourself and go with your first instinct. Always buy the better sounding amplifier, not the one that has more power on tap.

FWIW, my room is a little bigger than yours and my 8 watt amplifier provides more than enough power for all kinds of music, both loud and soft. My speakers aren't much more efficient than your JBLs either, if at all.

chrisby · « **Reply #34 on:** 21 Dec 2010, 10:15 pm »

all pontificating and personal insults aside, and getting back to eclein's original question - from the initial description, I'd opine you could probably be very happy with 30-35watts of decent tube watts - particularly if as Quiet Earth alludes above, it's for your own listening pleasure, and not impressing your "expert friends" - an ultimately impossible task as it's a moving target

guess watt? - not even all tube watts are "the same", either dynamically or tonally, and the only way to be sure is to taste test a few in your own system

this of course is much harder to do these days, as the few bricks and mortar retailers still carrying any vacuum tube equipment tend to the higher price ranges, of which there are many noble candidates

if you're willing to try the DIY or kit route, there is suddenly a much wider array and budget from which to choose

eclein · « **Reply #35 on:** 21 Dec 2010, 10:38 pm »

I'm all about what sounds best...if it's 2 watts or 200 it doesn't matter to me as long as the sound is right.

Thanks guys for all the input.

davidrs · « **Reply #36 on:** 21 Dec 2010, 10:59 pm »

Quote from: eclein on 19 Dec 2010, 04:46 pm

I am seriously considering getting a tube integrated or tube amp and I don't really know how much power I need.
My room is like 12 X 16 roughly and my current speakers- JBL 4312A's are rated 91db sensitivity and I listen nearfield at comfortable levels, when other audiofools drop by they usually want to turn up the volume.

Hi Eclein,

My room is around 13X26X9 feet.

Speakers are 94dB 8ohm, three active drivers, two passive woofers.

Speakers are 9 ft from each other, 5 ft from the front wall. I am 12 feet from the center point between the speakers.

I generally use my tubed integrated with its Pentode setting: 60wpc KT88 push-pull.

With this setting, I usually listen at the 9 to 10 o'clock position. Never over 11 or below 7, often enough at 8, as I am doing now.

In its Triode mode 35w, add +2 'hours' to each value, for ~roughly~ the same spls (to my ears, not measured).

Hope that helps.

- David.

SteveFord · « **Reply #37 on:** 22 Dec 2010, 12:59 am »

Here's my two cents - I'd do 60-100 wpc as it's always nice to have some power in reserve. It will also allow for some flexibility if you get some less efficient speakers sometime down the road.
That offer from Rollo is incredibly generous, I'd take him up on it and see if that's got enough power for you.

srb · « **Reply #38 on:** 22 Dec 2010, 01:09 am »

Eclein, I also agree you should have some power in reserve. May I recommend a pair of the Audio Research Reference 610T monoblocks with 16 X 6550C output tubes and 600W per channel (@ 16 ohms - not sure what the power output is at 8 ohms)

Steve

eclein · « **Reply #39 on:** 22 Dec 2010, 02:09 am »

Steve, I'm not sure that's big enough..you have no idea how much I needed a good chuckle, I'm currently residing in my local hospital awaiting further testing to find out why my chest feels like it's wrapped in a huge elastic band and both legs are numb from the knee down-the upside is the food is made to order and my room with flat panel tv is nicer than alot of the finer hotels I've stayed in.
Free Internet!! I'm not dead so life is good!