Nuforce Reference 20 Mono Amps Review
Equipment and Room:
Ayon CD5’s with 1980 NOS Reflector tubes (Transport, DAC and preamp combined). Nuforce Reference 9 V3SE mono amps (highly modded with on/off and fuse circuits removed, Furtech IEC, Mosaic boxes on top and mass-loaded with lead bags, isolated mechanically and electrically). Von Schweikert VR5 Anniversary MK2 speakers. All Master Built Signature Power cords, and biwire speaker cables. Masterbuilt Signature Ultra IC. Front wall, side walls and floor and windows treated for reflections. Room 38 by 22 feet.
Using live acoustic music and a grand piano in the same room with the system as reference, I finally had my system to a very nice place where all commented that it was clean, clear, revealing without harshness, and involving. All the mods to the 9's had improved them considerably over stock. It should be noted that I am blessed with very clean power. I am the only house on the outside transformer and the system is wired into a panel separate entirely from the main house. Prior to trying the new Ref 20, I had recently auditioned several amps in my system including the well respected Merrill Veritas, Hypheus Anvils, Chanel Island D500's and also the Hegel H30 in another system. I preferred my modded Ref 9's to all of them, so my 9's will be the basis of comparison. I really did not need the extra watts, as my speakers are sensitive but wanted to hear if the 20's might be beneficial in other areas while preserving the Nuforce magic.
After a longish wait for the first production models, mine finally arrived in an easy to open hinged wooden case with excellent deluxe foam packing, and soft cloth covers. I used an A-B-A-B comparison model, first playing the 9's, then the Ref 20's for a hundred hour break in, then back to the 9's and finally the 20's again. This took discipline because once I put in the 20's I was reluctant to remove them because I was enjoying them so much. I used my reference tracks spanning orchestral, classical solo (particularly piano, organ, and violin), jazz, pop, and rock. The 20 break in period was not bad, the amps were more detailed out of the box with an improved sound stage. By the end of test the 20's became more relaxed, liquid, and airy. I tried Metallica and Led Zeppelin to make sure that the liquidity was not artificial and when the music was supposed to be driving and edgy – it was in spades. Yet lovely and liquid music was more so than I have ever heard on any system. Piano which is both liquid and percussive with wood, string, and felt-hammer timbre was spot on.
When I reinserted the 9's it was not like they were broken: they were still sounded wonderful, but the 20's dramatically deepened the soundstage and also allowed the instruments on the edges and background to sound more realistic with more bloom and air. The 20's also have incredible micro and macro detail and at the same time are more refined and relaxed without losing the punch. I listened to a Caverna Magica piece where there is a man and a woman very softly speaking in a cave while other more prominent sounds are occurring. With the 9's I finally figured that they were speaking French; with the 20's I could easily follow whole sentences. Bruce Springsteen and other signers who are fond of slurring or mumbling words, were much clearer and yet natural. The 20's bass was even better than the bass terrific 9's, having more satisfying weight, bloom, and differentiation. All vocals were improved in naturalness. Close-miked harmonica and female singers which could be grating at high volume with the 9's, were just clean and present with the 20's. Timbral density and attack/decay, as well as speed were improved. All these were little improvements over the 9's (except much improved soundstage) yet the overall presentation is shockingly better and more natural. The feeling of enjoyment is very close to the best vinyl rigs in density, richness, and naturalness but with the strengths of digital. When I open my eyes the sense of the singers and instrumentalists being in the room actually increases, speaking to a big increase in presence without any forwardness. It feels equivalent to an entire system upgrade! I would encourage an audition for people with revealing systems, and feel the Ref 20's are competitive with amps of reference quality regardless of price.