The heat you describe sounds like it's in the vicinity of 55 degrees C. If it were over 60 you probably wouldn't be able to hold your hand on it for a long time (old time rule of thumb for checking transformers, etc.)

The original Manhatten Project in WWII produced the first atom bomb, which was nicknamed "The Gadget".

  Isn't it only possible to do that in the morning of April 1?   (edit: missed out word "do")

  I suggest you read about the original "Manhatten Project": you will discover the meanings. These are just project nicknames used by Mike, not the eventual product name.

@Jason Stoddard can you dispel some of these Vidar myths that are surfacing, before it's even been officially launched? I'm sure some of them are nonsense.

  Have you got the latest issue?

  Amps depends on your mains voltage (here it is 230 Volts). I don't see your location disclosed. Use Ohm's law:  Amps = Watts / Volts.

  40 Watts... it's on the Schiit website, http://schiit.com/products/freya.

The problem with bridging stereo amplifiers to make mono block amplifiers is that, while increasing the "headline" power output, each amplifier output "sees" only half of the loudspeaker's load impedance.  So low impedance loudspeakers present a more challenging load.  In the example above, 4...

Why do you need a pair of bridged mono blocks? Those speakers appear to have 94dB / 1 Watt sensitivity. How loud did you want them to go?  A single stereo Vidar will drive 200 W into 4 ohms. That is +23 dBW, so will put you up to about 120 dB of sound pressure.

You need to know what the separate impedances are when bi-amping. Just treat the high and low frequency sections as separate speakers and do the maths accordingly.

Yes, loudspeaker design is such that often sensitivity is sacrificed for other design goals, e.g. small size or better measured specifications. physics means that there's no "free lunch".

  I think it's no different than people who buy cars with powerful motors (e.g. massive V8/V12). How much power do you really need to go to work and pick the kids up from school? It's satisfying when you put your foot down...

"Choke input" topology has the choke before the capacitors (directly after the rectifier). This has different physics from a "capacitor" input filter, requiring different formulae. You are describing a "pi" type of filter.

@Jason Stoddard - Do you have specs for running Jotunheim into 8 ohm loads?  It looks good for a 3 or 4 watts at least, from the 16 ohm and 32 ohm specs. Or does current limit kick in and spoil it?