Preamp choices:Short list


Ok so I want to transition to a truly balanced system. My current components are single ended only. I have 3 choices of pre's: BAT vk-42SE, BAT vk-23SE or Rogue RP-7. Are there any clear front runners? (Note the 42SE is older, carries risk of servicing?). Thanks
jimbones
I have a single ended triode par of monoblocks which I built because I can't afford to buy what fits my tastes. For my preampier I have always used a simple SET using either a 6J5, a 76, a 6P5, and finally Arcturis 27 because I like blue glass instead of clear glass and the 27 has a wonderful sound. I found an Alps volume control sounds more alive than the stepped attenuaters using the best metal foil resistors. They are easy to build and you can build the power supply in a separate chassis to keep stray transformer magnetic fields away from sensitive circuits. I have a 45 SET amplifier but I discovered Magnepan speakers which sound to me more like a live performance in the opera house than vastly more expensive and complicated cone speaker arrays with all their crossover and resistor, capacitor, inductor equalizer circuits to compensate for the back EMF electro-mechanical deviations in frequency response. But a 45 can't drive Magnepans. I ended up building a pair of 833A monoblock amplifier stages and replaced the output transformers on the 45 amplifiers with Lundahl LL2736 transformers the 600 Ohm outputs I connect between ground and the grids of the 833As which are very linear at 1000 anode Volts and zero grid bias Voltage (they draw about 115 ma.) I put the 833A amps on the floor next to the Magnepans and run thin Teflon insulated wires from the 350 plate Volt B+ out to the Lundahl 5k windings and back to the 45 anodes. This higher Voltage low signal current over the long distances from my 45 amp and preamp cabinet circumvents the dilemma of long speaker cables vs long interconnect cables and is insensitive to induced noise; it has all the virtues of high Voltage power-lines for cross country power transmission. Shielding and capacitance between wires is insignificant.
Even if I could afford the luxury of buying factory amps and preamps, I would lose the freedom of having exactly what  want and prefer.
I don't know if this fits your criteria but First Sound makes the most musically and emotionally engaging line-stage preamps I've ever heard. And I've auditioned quite a few high-end systems. Emmanuel's preamps are also upgradable (within certain limitations) so you can start with a preamp that's within your budget and later upgrade if you wish. You can contact First Sound with any questions you have.
Hello Jim,
I used the Rouge RP7 with a pair of Esoteric MG20 speakers. These are not bass heavy speakers. But they are very good detailed speakers that physically disappeared when played through the Rouge RP7. What I was very excited about was it balanced the sound beautifully without the use of subs. I used these speakers through a Mark Levenson and a Hegel 390 integrated amps. With these two brands they lacked a balanced sound they lacked bass. With the Rouge RP7 the sound was perfect. That says a lot about this preamp. 
I would second the recommendation of the PS Audio BHK Signature preamp.  There is a link on this page for a video of Bascom H. King talking about balanced audio.  

https://www.psaudio.com/bhk-preamplifier/