As valve amps are being considered, here is my latest DIY effort., Felicity.
Inspired by Andrea Ciuffoli's top level OTL amp, #3
I use a 12SN7 as the gain stage as I have a good selection of top quality NOS, and 5687 output valves (compatible with E182CC) as I have several; E182CC are on order.
I have increased the power supply voltage, allowing larger value load resistors above the 12SN7 and below the 5687, to keep distortion low.
The power supply is a typical one of mine. Valve rectified by 6BY5 (paralleled) as it sounds good. 3 stage supply with low resistance chokes in each stage, and poly/oil motor run caps (no electrolytics); tuned for fast clean transient response. The final stage is split by channel, making 4 chokes in all (one is inside).
Chokes add robustness to a PSU, somewhat like a degree of regulation. The supply is unregulated, as regulation may tend to be less organic and natural.
Note my words 'may tend', as I know there are many fine supplies of different types! There is no one perfect solution or we'd all use it. I choose my poison as I'm familiar with this kind of supply and it suits my taste, sounding a bit less like hifi if you see what I mean.
Volume control is a stepped attenuator with Dale resistors, excellent sounding, but I may fit a Goldpoint some time (I use one in another amp).
Output caps are Jantzen standard Z caps 100uF, polypropylene, fairly good caps, but it's about the best that will fit - their Z cap supreme are excellent but too big. But even this lowish quality cap is an order of magnitude better than electrolytics (see the tan d loss values if you don't believe me).
Even with only a few hours on it, the sound is good; very transparent, fast transients, good dynamics, musical, good vocals, decent tone. Unlike some valve amps, this is fast and powerful sounding. I know there is more to come in terms of sweetness and tonality with running in, but these are OK now; Kate Purcell's voice is fine, guitars have tone, and the music is rhythmic with a good beat.
I think it's going to be a bit special ....