First foray into tube amps

High Efficiency Speakers:

• Klipsch Heritage - easy to find to buy and sell used
• Volti - a step up for more money 
• Omega
• Zu

If you are willing to sell a kidney, you should also check out Songer Audio field coil speakers.  The field coil Audio Note speakers are interesting too, but that would require selling both kidneys.

If you can get to the Washington DC/Northern Virginia area, check out the Deja Vu Audio shop for both their custom tube amplifiers and custom horn speakers.  Their lowest cost horn systems are around $15k and they sound terrific to me.  All of the tube amps they make are low in power.  These days, most of the amps, linestages , phonostages, and DACs are expensive, but they also sell stuff from other manufacturers and used gear traded in by customers.

What exactly is that BBC mid-range magic? No bass, no treble? ....which leaves a BBC sucker with some mid-range, I bet.

I love that BBC mid-range magic, and think I want a little more warmth than I have 

I been sat in front of on a few occasions pre covid a Maxonic Field Coils, they were part of a £200K -ish System. 

I can't state how impressed I was with the Speakers , as much listening was about the influences on end sound from other devices.

I even heard a £20K-ish Phono Cartridge used with these drivers, about  £100K of transducers allocated to one system, not too common that one.

I will state, that I never felt a better speaker was required to get the handle of what was undergoing demonstrations. 

Hello! 

First foray into bottles....  nice.  The absolute FIRST RULE in buying tube amps, the manufacturer must be around and stand behind the product, otherwise you’ll have an expensive paper weight and a hole in your wallet.  

Next, ask yourself how much heat gain inside your listening room can you tolerate?  Have forced air AC, or just limited to good old windows with a box fan in it?  

The aforementioned are absolute, especially servicing your amp.  For example, old Mark Levinson amps like the 336, 33H, 33, etc. are SS, but for the purpose of this discussion, in my experience,  shops generally do not like servicing these amps.  These amps get very hot because they are biased high, hence they cook the caps.  The ONLY place I’ve gotten to service my old 436 was 3MA in TX, and George Meyer on the west side (of Los Angeles).  Okay, enough of that...  

How are you with a multi meter and taking the covers off amplifiers?  If you are not comfortable with removing the top case, then you MUST buy an amp where all the tubes are exposed.  Old style tube amps, they require hand basing with a multi meter; if this is not your jam, then an amp that auto biases the grid to heat the tubes is mandatory.  

Next, what is your tolerance for buying expensive tubes like KT 150 and KT 170 bottles?  If you do not like doling out bucks to replace tubes, then your choice is a less powerful amplifier.  Do not get a big VTL, or  Audio Research 750 or 610 amp.  

Have you considered maybe a hybrid amp that uses a tube input stage but uses output devices for the hard work?  A signal tube does not work as hard as a power tube, generally.  

Then lastly there is budget.  I mean you can go from a few thousand to multiples of thousands of bucks.  

Anyways, enough of the psycho babble. 🤣  In your post, you said you like midrange warmth.  Let me start with Lamm amps.  These guys are something else.  I have ML-1.1 monos, and they are glorious, 3D in front to back, left to right, and everything in between.  Midrange is beautiful.  Lamm makes all tube amps, and hybrid amps that carry the house sound but they bring more in the way of transient attack, better dynamics, and a more bass.  These are expensive so if your goose that lays your golden eggs is on vacation, buy used of these.  

I’m rambling on here so I’ll make this short.  Some solid state amps do a great job at doing midrange bloom and romanticizing the presentation to some degree.  This would be Pass Labs Class A amps.  The ".8" is the current generation and the ".5" is the previous.  I personally like the greater midrange warmth of the .5’s.  I really like the midrange bloom of the older Aleph series of amps.  Okay, last thing, there is this thing about preamp plus amp and their interaction to reinforce the that house sound if both are from the same manufacturer.  Equipment that has symmetry between one another is very important.  Some preamps don’t play nice with some amps & vice versa.  Last, last bit of advice, listen to it with you own music when you go audition the amp. Happy bottle amp hunting.