Amplifier for Cornwall IV

A very cheap, but quite good sounding, approach would be to build the Elekit 300b amplifier.  Even if you don't have much in the way of soldering and other amplifier building skills, these can be learned on line and the it should be relatively easy to build if you go at it patiently.

A far more expensive alternative would be to buy the Synthesis A40 integrated amp with built in DAC.  This is a 40 watt per channel amp that runs one of my favorite tube type (KT66).  The built-in DAC is also quite good.

The Cornwalls sound very good with low-powered tube amps, whether  modern or vintage.  I would take advantage of its efficiency to utilize such amps because they tend to sound so much better than either solid state or high-powered tube amps.  Of course taste varies, so I won't say that any particular amp is terrible.  But, I will say that one should at least explore beyond the most popular options out there; look at options beyond Decware, Prima Luna and McIntosh.    

While I haven't heard solid state amps that sound quite like better low-powered tube amps, that is not to say that some remain nice choices.  I liked the First Watt J-2 amp I had in my system for a couple of weeks.  I have also heard some nice systems powered by Ayre amps and Rowland amps.  These days, solid state amps DO NOT sound harsh or grainy or unpleasant as they did in the past.  Rather, they sound a touch lifeless unless played loudly, and are not quite as engaging (one's interest in the music tends to wane earlier).  There can also be a slightly artificial "edge" to the attack of notes with solid state (also the case with many high-powered tube amps), but some people like that sound.

A local dealership that sells only tube amplification has a Parasound JC-1 amp.  I asked the owner why he has that amp and he said that he heard that it is one of the better sounding solid state amps.  He uses it for demonstrations where customers want to hear a direct comparison between tubes and solid state.  In other words, he uses the solid state amp to make sales of tube amps.  It works.