In search of low powered tube amp that isn’t overly hot

I am interested in recommendations for a low powered tube amp that is excellent sounding that won't make my room overly hot.  Speakers are high efficiency so I can get by with 10 and maybe even less than 5 watts. 

@mcanaday Several years ago I hand-built an amp for my bedroom setup. It had to be reliable since I was likely to fall asleep while playing it. I listen to it quite a lot. Finally someone in the industry asked why I wasn't marketing it. I didn't think anyone would want one, since usually lower powered tube amps aren't taken all that seriously. I wanted something built to the level of part and circuit quality as you expect from a higher powered amp so that is what I built. It makes 5 Watts/channel. 

But a couple of years ago a speaker manufacturer was adamant: 'why aren't you marketing that??' I really didn't know what to tell him,  but since it had cost nearly the same to make 10 chassis as it did one, when I originally designed the amp I had 10 chassis made even though I didn't think it would go anywhere.  

I don't think an SET can keep up with it- so far anyway, not heard one that could. Plus its a lot more compact, being able to sit on a sheet of notebook paper with room left over. I'm of the opinion that if you really want to hear the best of tube amps, a lower power push pull amp of no more than about 20 Watts, using a miniature pentode power tube (wich is important since they are designed to be very easy to drive, so allow for a very simple circuit), sits right at the sweet spot. If you design it right, it has the potential to be one of the better sounding tube amps available, SET or no.

I built this one up with black transformers and a blue chassis.  

The Music Reference RM-10 Mk.2. 35w/ch produced by a pair of EL84's per. John DeVore chose this as the "medium" power tube amp in his reference system.

There are a couple of Elekits that might fit the bill.

The TU-8400 which can be used with a variety of octal based tubes and the TU-8900 which takes the 4 pin 300B or 2A3 tubes.

The 8900 is not a project for someone who has never used a soldering iron but they can be found pre-built.

I use the 8900 in my 2nd system, fed by an Eversolo DMP A8 and driving a pair of Harbeth P3ESRs. In my case it lives on top of a bookcase but given an open back with at least 6 inches above it and to the sides Google AI suggests you should be OK.

The 8900 is a very good sounding amp - I have had in my "big rig" driving Atria IIs.

My "summer amp" is a Coincident Audio Dynamo 34SE MK.ll. I use vintage Mullard (for the EL34 power tubes), and vintage RCA's for the 6SL7 input tubes. It puts out much less heat than my KT88 based regular amp, and sounds very good. It is not the current model - there is a MK.lll and other amps. But I got mine used for around $1200, and it was a bargain. I have efficient horns, and this little guy lights them up effortlessly. 

Anyway, look at Coincident, new or used.

David

@mcanaday 

dynaco by will Vincent 

he is in idaho and sells on usam

brands himself as laboratory west

very solidly built amps and lots of happy people with them