[sts9fan]

I have a pair of Paradigm Studio 60's that I am running with a reciver now but I think I want to upgrade to some sort of amp. My question is why do tube amps usually put out less watts compared to a ss that would be used for  the same speakers. Also how many watts of tube power would I want for my speakers?

[miklorsmith]

Tube amps generally put out less power because each individual output tube provides limited amplification.  You will see some very large (200 wpc) tube amps, but these generally have many, many output tubes which collectively are very, very expensive to replace.  Economically, you're best off with tubes amps that are no bigger than you need for your application.

My solution is to have upstream gear with tubes that are smaller, cheaper, and fewer so that a replacement event costs $25 instead of $1,000.  Couple this with SS.  If you're seriously looking into tube amps, check availability and prices of the tubes the amplifier uses.  It's not a bad idea to have an extra set (or two or three for rolling) lying around, just in case.  Also, check how bias is set for that amp, as the adjustment can vary from automatic to technically inclined.

[sts9fan]

by upstream do you mean the cd player??

[Marbles]

by upstream do you mean the cd player??

Or the pre-amp...

[Parnelli777]

Jolida JD 1501A hybrid integrated- $650.00 without remote, $750.00 with.
Used at around $450-550.

You'll get a good start with the tube sound for dirt cheap. Your speakers are fairly efficient, 100 watts is more than enough. If you want to spend more, take a look at the Jolida JD 801A.

[Afterimage]

Integrated hybrids are not a bad idea.  I don't know what you budget is, but the Unison Unico SE is also one to consider.

[JLM]

The waveform of a single frequency signal is in the form of a sine wave, and looks like moving a loose rope back and forth on a floor, with constant distance between the top and bottom peaks.  Your speaker drivers move back and forth the same way to reproduce that frequency.

At an amps maximum output the waveform is still smooth and the distance from top to bottom of the waveform has reached the amp's limit.  When the amp is pushed too hard (beyond its rated output) the tops and bottoms of the waveforms flatten out, looking like they've been clipped off.  This is what what people refer to as clipping.  

Clipping is especially bad for the speaker.  Instead of the drivers moving smoothly in and out like the rope as it follows the single frequency waveform signal it has to stop moving completely and instantaneously as it hits the flat clipped portion and hold position.  Then it must start moving, again instantaneously.  This holding position, high acceleration, and high deacceleration is not what the speaker was designed to do.  It generates excessive heat and can melt the voice coil, ruining the drivers.

Tube amps "soft" clip, meaning that the transition from the natural curve to flat has rounded edges.  Solid state amps "hard" clip, meaning that there is no transition.  The audible difference is obvious!  To avoid clipping suggested amp ratings are often made higher for solid state amps.

[_scotty_]

JLM, actually the flattened part of the wave form as viewed on an oscilloscope is essentially DC with a constant maximum power level. This is what generates the the voice coil heating and may also result in the driver cone exceeding its maximum excursion limits and popping right out on the floor.
 Instantaneous acceleration in response to an electrical signal is what the loudspeakers were designed to do and is not by itself a cause of driver damage.
 sts9fan, to specifically answer your question, tube amplifiers can sound more
dynamic and powerful than solidstate amplifiers. Because of this, many people feel satisfied with lower powered tube amps.  The soft clipping aspect,
courtesy of JLM, also contributes to this perception.  At the end of the day amplifier power is your friend. More speakers have been damaged by too small an amplifier than too big an amplifier.
Scotty

[JLM]

Another aspect to consider in shopping for amps by power rating is the logrthymic relationship between watts and dBs.  So 90 dB is twice as loud as 80 dB and it takes 10 times the power to achieve with the same speaker setup.  BTW a 3 dB increase requires a doubling of power.  Your speakers are rated around 90 dB/w/m, meaning that one watt will produce 90 dBs at a distance of 1 meter (in open space).  In a 1500 - 2000 cubic foot room (typical residential rooms) the room gain plus the gain from having a second speaker balances out the loss from sitting more than 1 meter away from the speakers.

It would be really good for you to buy/borrow a sound pressure level (spl) meter and test tone CD(s) to find out how loud is loud and what frequency range you need/want/use.  The vast majority don't realize how little of the 20 - 40 Hz or 10,000 - 20,000 Hz ranges are contained in music.  IMO the "requirement" for 20 - 20,000 Hz is marketing hype and has done for more harm than good with it's biggest benefit going to the pockets of manufacturers and retailers.  The majority of listeners are usually surprised too at how low of spl's that they're using (most keep average levels under 85 dB).  So based on average levels you'd need less than 1 watt per channel.

But thanks to the digital age, the reality of live music, with it's wide spl range (roughly +/- 50 dB) can be fully reproduced.  Note that various forms of music peak between 100 and 110 dB.  OTOH these are very loud and generally are not domestically acceptable.  From above, to reach 110 dB from your speakers you'd need 20 dB of gain or 100 watts per channel (wpc).  Amps that soft clip have typically 3 dB of additional headroom, you'd only need 50 wpc.  This is theory.  In real life you could probably get by with much less and be very satisfied.  This leads to another whole aspect of pulling together a good audio system, synergy between components, but this post has gone on long enough.

Scotty,

You're right, far better to have too big of an amp than too small.  But best to have an amp that clips gracefully (softly) to remove the issue entirely.

The sudden de-acceleration of hitting a brick wall or of taking a 20 foot radius turn at 100 mph is quite different than slamming on the best brakes alone or pulling 20 lateral G's.  In this case speakers = cars, neither are designed for those sudden starts and stops or turns.  Acceleration rates vary, but neither cars or speakers are designed to hit brick walls, make 100 mph hairpin turns, or clip.