I recently purchased one of Holton Audio’s  One-Zero-Zero Supreme power amplifiers that I had been keeping an eye on for some time now and very glad I did. I’m not a sit down and take notes type of  bloke, but paired with my Osbourne Epitome loudspeakers, a whole new level of sound has opened up. Sounds like I’ve moved the speakers further apart but they are still in the same spot, not sure how that works. Hearing a lot of small details in my favourite tracks that weren’t there before, and a lot of extra punch in the bass, many apologies to the neighbours.  I will have to revisit my music collection now to see what I’ve missed. Will be an enjoyable chore. Anthony was a pleasure to deal with, and I can’t recommend this little marvel of an amp highly enough. Troy P Victoria, Australia

Hi Anthony  Thought I would let you know how your amp is going. Received the One Zero Zero Supreme and have been very happy with what I’m hearing, straight out of the box it sounded much much better than my 100w Rogue Hydra Pwr amp and 150W Consonance pwr amp, both of which get very good reviews, now after about 30 hours of use its sounding incredible. Soundstage which already was deep and wide has grown and also projects forward more now as well, Bass has more impact and depth,  also transparency and detail has increase dramatically. I have owned some very good amps over the years including Tom Evans SET amps,  Audio Aero Capitole and Stereo Knight monoblocks, I can comfortably say your amp not only competes with these great valve amps but in areas like bass and detail it surpasses them,  I’m sure as the amp gets more...

HPA-NXA50L I have built two mono blocks. Each has a 600 VA encapsulated transformer, a RCRC filter with 0,5 and 0,25 ohms resistors and 600.000uF electrolytic capacitors, inrush current limiter, a mains DC-filter and loudspeaker protection.  The  bias is adjusted to 2,85 A the heatsinks are about 50-51 degrees Celsius (125 F) when  warming up from about 22 degrees Celsius  is complete.  This should leave headroom for use even during a hot Danish summer. But a lot of cooling IS recommended and cooling can hardly be overdone. The sound is magnificent. No less. The soundstage is huge and very roomy, the tonal balance is very neutral. Details are abundant and very natural sounding.  They let you hear all the detail you could possibly wish for, in a way that sounds utterly right. The details are there, you can clearly hear them, yet they do not seem exaggerated, on the contrary,...