If I remember correctly MLundy has a BHK preamp and a pair of the new M1200 amps running the NX-Otica MTM.
He'd probably be the best person to talk about the BHK setup.
But yeah its all super subjective..
Yes, my current set-up with the NX-Otica MTM/dual servo sub combo includes the PS Audio DirectStream DAC, BHK preamp, and M1200 monoblocks and yes, this system sounds gloriously addictive.
However, over the past 3-1/2 years I’ve had the ‘Otica monitor/sub combo, I’ve had many different electronic setups. These have covered a wide variety including an AudioQuest Dragonfly DAC with a 5wpc OddWatt Poddwatt integrated tube amp with a preamp output for thesubwoofer, a Geek Pulse X Infinity DAC with a DODD Audio zero gain preamp and PrimaLuna Prologue 4 35wpc stereo tube poweramp, a PS Audio Stellar Gain Cell DAC/preamp (GCD) with the Prologue 4 power amp, the PS Audio Stellar GCD with a PS Audio Stellar S300 stereo solid state amp, to the current setup described above.
This is the important take away, the NX-Otica MTM monitor/dual servo sub combo is an exceptional sounding speaker regardless of what you have in-front of it. The write-ups of my rooms at the last three Lone Star Audiofests will attest to this. The fact that these speakers sounded so good with modest electronics yet kept significantly improving with each level the electronics went up is a testament to Danny’s skill as a designer.
My advice to the original question is to determine what type of outputs your sources have then, within your budget, get a DAC and/or preamp that will accommodate these inputs and has the type of output to the power amp you want. If you are going to use separates and want to be able to run a balanced cable, the preamp needs a balanced output and the power amp(s) need a balanced input. If you are running a balanced cable from the pre to power amp, use the A370 XLR3 version of the sub amp. That way you can run balanced cables to the subwoofer too. My BHK preamp only has one set of balanced outputs so I run XLR cables from the preamp to a balanced splitter close to the power amps. One leg For each channel of the splitter can have the inline filter caps which would be connected to the power amps driving the ‘Otica monitors while the other leg is left full range for the subwoofers.
At about 95dB efficiency, the ‘Otica monitors can be driven by just about anything. The simplest configuration is an integrated DAC/preamp/poweramp. The upside is only having one electronic component. The downside is you won’t be able to keep the low frequency energy away from the monitors. The next simplest would be two components, A DAC/preamp and a stereo power amp, then you can have the DAC preamp and power amps as individual components.
When choosing a preamp, consider getting one that not only has inputs for your current sources, but will also accommodate any source you may add. As for which brands, as long as you choose components from a company or companies that take sound quality seriously and, if from more than one company, are compatible with each other, you will have a system that you will enjoy listening to.