Herron M1-1A monobocks, what do you think?

I also have the entire Herron set-up (VTSP3Ar02, VTPH-2, one pair M1-1A, one pair M-150, all Herron cables), except for digital. The M1-1A amps are wonderful and a great match for upstream components. I have not had a problem with low impedance speakers, running a 3.5-way system with low impedance (down to around 2.5 ohms) bass section. Clean and tight. I use the pair of very early M-150 amps on some < 4 ohm subs (below 30hz) with a large boost. No problems.

My M1-1A pair came after Herron did a breakin. But they still sounded a little better after a month or so. I leave them on 24/7 so I can't comment on warm-up time.

I really like the M1-1As. They are very detailed, great dynamics, very tight timing, nothing harsh. Neutral perspective, vanishingly low distortion. Everything sounds "right" in a way that I have not heard in any other system using other electronics.

IMO, the Herron M1-A1s seem to have the best attributes of both tubes and solid state. They are a very nice step up from the already excellent M-150s. I have no want for an upgrade.

I like the Herron cables with them. Clean, honest, no filtration, no distortion. Cable resonance seems to mate very well with Herron's gear. I use the standard power cables supplied with the units.

I have the VTPH-2 and VTSP-3Ar02 on Vibrapod Cones. Only use StillPoint cones under the turntable (original VPI Aries Extended / JMW-12). I want to try the Vibrapod Cones under the amps eventually. Also want to add solid laminate bamboo cutting boards under the amps. In the meantime, I'm just enjoying the music.

One small note: IMO, different cables with Herron gear can provide somewhat variable results. Stick to pure copper, no silver in the audio circuit. I've heard a few pure copper cables besides the Herrons that sounded good in my system. Every time silver is introduced, the treble seems to harden, instruments lose that natural presentation.

I hope I am not hijacking this thread but I am using a VTPH-2 and VTSP-3AR02 and have been thinking about whether to replace the stock feet with something that will provide better isolation. I looked up the Ultramini's and Vibrapods on the web but have a question--How are you installing these? Do they thread into the chassis in place of the stock feet? Has Keith provided an endorsement for their use?

I use the Vibrapod cones under the VTPH-2 and VTSP-3Ar02 chassis pointing up. I have not removed the stock feet. Biggest improvement came with the phono stage but the pre-amp was better, too.

The Vibrapod cones are free standing, no studs coming out of them. I do not use them on top of Vibrapod discs. I just haven't tried that configuration so I can't judge the difference. But at the cost of Vibrapods, the experiment is certainly inexpensive.

I've spoken with Keith about the Vibrapod cones but can't recall the conversation except that he was cautious about making any suggestion or endorsement.

I would not try to thread anything into the spot where the stock feet are attached in Herron electronics. Check with Keith Herron first as there is very little clearance between the circuit board and the chassis. I do recall Keith saying something about that.

Under any circumstances, I'd still check with Keith to get his latest opinion.

Herron equipment is outstanding. The diligence Keith puts into his work is second to none.

I will swim against the current here and say I was underwhelmed.
Herron Audio is well-respected by all and enjoyed by many but, in my system, while the M1A amps sounded nice, clean, and pure, they did not display the same level of dynamics, impact and depth as the better amps I have owned.