Tube amps under $7500

If you go with a pair of Atma-Sphere M-60's (a great amp, which I have owned) or S-30, for use with a 4 ohm loudspeaker you will need the Z-Music Transformer, which raises the impedance the amp sees. OTL amps don't like low impedences.

Ayon Spirit. You can use it as a power or preamp or integrated 

@bdp24 Appreciate the warning. At this stage I should focus on amps with dedicated 4 ohm tap.

@passthedutchie Like you I would naturally incline to KT150s and wonder why the unit costs $400 less with these vs. stock EL34. 

Always a BIG fan of RM’s Music Reference work…including the power amps…but they are super neutral ….hardly overly tubey but very very musical… get fantastic RAM tubes for them !  9 mk2 or the 200. IF you have fairly efficient speakers or don’t listen loud, try to find the RM-10 version w hand wound by RM transformers…. a grail amplifier…imo….

Yes, as I mentioned above, OTLs may not work with a low impedance load.  Adding a transformer to lower the amp’s output impedance sort of defeats the purported advantage of being transformerless.  I personally don’t care about such theoretical problems and like the sound of iron anyway.  The M 60 and M 30 are very good sounding to me, although a touch lean (i.e., not warm).  The Joule Elecktra OTLs were warmer sounding, but some developed problems with their tube sockets over time so one must take care buying those amps.  The bigger Atmasphere amps sound very good and are a touch warmer, but even used they might be beyond your budget.  The bigger Atmasphere amps use more output tubes in parallel to increase output and this also lowers output impedance so they should be even more compatible with your speakers than the M 60 or M 30.  When they are compatible with your speakers, OTLs kick ass-they make the music so lively and dynamic without being harsh.