I am thoroughly enjoying my Jolida 3502, which can be had for less than half of your budget of $4000. It is versatile, dynamic, and sounds great.
You might also check out the PrimaLuna line, which a lot of people like.
I’ve had a "factory upgraded" Jolida 502p for years and am so impressed with its quiet and powerful presentation of tube slam and refinement I that I don’t hesitate to recommend this stuff…that 3502 looks cool, and hey, it’s still much less expensive than any comparable amp from anybody else. There are very few new reviews of Jolida amps, and simply zero ads in appropriate magazines…not sure if there’s a connection there, but modern Jolida (the MD guys) gear deserves some props for design and execution. Having personally compared my amp (a few times in my own listening space) to similar amps costing much more money from frequently reviewed manufacturers, I’ve felt the Jolida is simply better sounding, or at least every bit as musical as the much more precious stuff.
+1 Jolida! I've always liked their gear. My FX10 was such fun in a desktop office system. Always punched above its weight to be cliched about it. Very inexpensive, yet truly good sound and design. I always thought Jolida (MD) should have upgraded that model slightly, charged a few hundred more bucks for an extra input, better volume control...many folks would wonder...why pay more??? Their other models are stellar. I don't own those but have heard them in enough different folks systems to know how good they are.
I'll second wolf_garcia's and other's comments about the Maryland-based Jolida. Had a Jolida 502B for a decade. My intro to tubes. Good value for the money. The factory upgrade for it was another high value bargain. It responded readily to tube rolling. It's well within your budget. I liked the fact that biasing was manual (and easy to do, I might add). Only reason I stopped using it was I needed more power for some lower efficiency speakers. Good luck in your search.
I listened to a couple Primaluna integrateds and was searching for a used one and came across a Manley Labs Stingray II. I preferred the sound and ended up buying it about a month ago. So far I am very pleased with the sound - rich, warm with some nice low end punch. As a bonus, the American made amp features a unique industrial design that is pretty showstopping. All my friends, even those who don't give a hoot about stereo gear, have commented on it.
Bottom line, there are a lot of great options under your price point. You'll have fun discovering the options. Good luck!
for 5k you can get a used audio note meishu (the sweet spot in the audio note UK lineup). It is a very highly regarded integrated amp. I've had mine for 20 years and i get everything i want out if it in a 350 square foot room and 93db speakers. You will need fairly efficient speakers unless the room is small.
A must listen is the Audio Research VSi60 or VSi75.
They punch well above their weight, and have the solid ARC house sound.
I might be selling mine (VSi60) in the coming weeks, but it would only be to go to Audio Research separates. But I’m gonna let it take a swing at pushing my Wilson Audio Sashas (in bound) when the arrive.
I almost got Cronus magnum 2 but kept seeing so many on secondary market figured it wasn't a great sign. I wanted Manley, but too expensive, same with the Cary sli-80...I ended up going for primaluna Classic, which is a great sturdy amp that holds its excellent value, haven't seen those on secondary market really...I do wonder what more watts would sound like sometimes, but look forward to upgrading to the KT-88s...the primaluna supposedly lasts longer, putting less stress on the tubes...
I have had a few system tryouts and ended with the Primaluna Dialogue Premium with KT-88 and NOS Philips 12AU7 as pre matched with Rotel RCD-1072 driving the ProAc Tablette 2000 Signatures. For the money that I spent on this current system, I could not be happier. What I like of this system is the real natural sound with rich lush midrange and 3-D like soundstage.
I have a Mastersound 845 which is a wonderful SET design. It may be just above your price range but they also have a number of cheaper units in there range
The Due Trenta SE retails for just over 3 thousand pounds (English) which I think is round about 4 thousand dollars
They also have another 2 integrated a couple of thousand quid cheaper
I'm from the UK so the above links are for the UK importer, I would imagine Mastersound have a US importer
Mastersounds web site is
Beautiful Italian styling combined with sublime sounds = happy listener