Watts! How many do we need?

@pindac

My most recent experience of a Valve Amp design producing 3 Watts Output, has been a revelation.

3 Watts of valve amplification may be sufficient to drive some very efficient speakers in a small room in nearfield listening mode. It may produce all the fine attributes you mentioned but for most meduim/large speakers in a medium/large room setup this wattage will certainly not be sufficient.

In the context of how many watts we need, with all the virtues of valve amplifiers, 3W/10W/20W will not be able to energies any meduim/large room in any satisfying way in many/most cases. One should also be guided by speaker's recommended amplification.

In my case,  I was once interested in a very high end 50W valve amplifier but when I spoke to the manufacturer they said for my speakers and in my room 50W will not be sufficient! I will need 160W valve amp to be fully able to energise the room and get the best out of my speakers.  There must be a reason why the company also sell 250W valve monoblocks. My speaker's recommended amplification: 50-1000W into 8 ohms. Sensitivity: 90dB  .

@rshank64

@rshank64 In posts made, I attempt to only write and share of experiences had.

As this report made is the description being offered of a very very recent experience had, the content has a relevance to the Topic of this thread.   

I am not reporting on a Audio Retailers opinion.

The Speakers were placed in a room with Dimensions approx' 24' (7.5mtr) x 17' (5mtr) approx' 6' (1.8mtr) from the rear wall), 2' (600mm) fom the side wall, with a spacing between the Speakers of 12' (3.6mtr).

The first row of seating was 10' (3mtr) extending back in two more rows to approx' 15' (4.5mtr)

Between a group of eight in attendance, of which none were a nearfield listener, and one attendee is a active Audio Retailer, another attendee a retired Audio Retailer, there was only talk of the very positive impression that was being made by the 3 Watt Output Amp' within the whole group. The Group were not familiar with such a sound that was present, Voluminous Soundstage, with noticeable/notable separation, accompanied with detail retrieval that was hard to fathom, how it was able to manifest as an end sound. The designer made it known where some of the electronics in use were not conventional, and are a contributing factor.  

Five Sources were used, both Digital and Analogue, using Silver Interconnect Wires and Silver Wire Speaker Cables.

Immediately after the 3 Watt Ouput Amp's demo, a 30 Watt Output 300b Power Amp was put into service.

There was zero audible evidence this Amp' was doing a Better Job of Driving the Speakers and Coupling to the Room, even though the 3 Watt Amp' was using much of the VC to attain similar dB levels. There was plenty of evidence to show how the two designs are separated through an end sound produced 

As good as the 300b is as a design, where the circuit is TDP designed Transformers and is using interstage Tranxs, as well as a very careful selection of resistors that have been highly thought off over the years.

The assessment (not hearsay) for the the new concept design Prototype 3 Watt Output Amp' has been an indelible experience leaving a large impression for an attraction to it. The Amp' is very much worthy of being commented on, especially in a Thread of this Topic.   

Enough to cause a brown-out in your neighborhood at will. 

@pindac
Thanks for the detailed description  of your experience and surroundings where this demo took place.
That is indeed a very impressive performance from a 3W valve amp.  It is very encourging to know that there are new valve designs in development which may change the way we experience audio.
Hope this product will be made  available to all to evaluate, purchase and enjoy in the near future!

@larryi 

If watts tell half the story, which advertised spec of the amplifier is a better indicator? I understand amp x volts = watts. However, based on my basic search, amplifier specs don't advertise/disclose this info.I need one more variable.