It was a really cold winter this year...seemed to start in October in Central NY, and as of this review IT IS STILL HERE. Given the length of the season and minimal available outdoor activities, I was able to really sit down and listen to my system with probably more of a critical ear than I have had since adding the superb Blue Circle Audio 2K4sh custom amp that Gilbert built for me. When I first got the amp, I spent considerable time with the Tube and SS control knobs that Gilbert added (akin to the BC 307) to get the tonal balance to my linking in a general context, then small deviations (sometimes more tube, and in some cases more SS, which gave the sound more impact (with drums especially)). During that time, I had exchanged more than a few emails with Gilbert, on some of the triumphs I had as well as some of the challenges with having this much flexibility versus an on/off switch of the standard model. To be honest, having an unlimited amount of sound tailoring can be bane as much as bonus. It is kind of like a buffet - so many choices and the feeling that you may not get what you want in the end, with the circular conundrum of repeated excursions from the listening position to the amp...small adjustment...return...listen...wash, rinse and repeat.
During our correspondence, Gilbert informed that he had newly modified the tube to SS blender circuit (beyond what he did on the BC 307 and my amp) with a novel modification to the 6SN7 tube circuit in the new Amherst Audio by Gilbert Yeung Design (AAbGYD) NSI-G. It didn't take me long to reply (minutes, I think ) and ask if he could modify my amp to the same effect - given my ever evolving requirements to "shape shift" the tonal balance and color saturation of the amp's sound, depending on and potentially specific to the a genre of music (or specifically to a single LP or CD). He said he would need to see my amp of course, so that he could determine how to go about the upgrade. I was all ears.
Then, something entirely unexpected happened. He sent me a note stating that he wanted me to first hear if the mod he did on the variable 6SN7 tube control would be something I wanted to do or not. I said, hey, that makes sense. He then asked if I wanted to listen to the NSI-G in my rig. What?? I am not a dealer or reviewer (or somebody who could actually afford that amp), but you want me to take her for a spin?? Why not, right?? The only stipulation, my end of the bargain if you will, was to write a review...this review of the NSI-G. After the shock dissipated, we settled on a date to meet and I got the NSI-G after it had been at Bob Neill's place for his test drive. Once back from a 8 hour roundtrip journey to Middletown, NY, and the loving support of my wife (God love her) helping me bring in two huge boxes into the music room, I was finally able to extract the power supply and the amp with a bit of brute strength and get it place (on carpet sliders, no less, which made it mobile) and hooked her up.
I have read and re-read what both Bob (Amherst Audio) and George (Entracte Audio) have said about the NSI-G (solid reviews by both gents), but NOTHING could have prepared me for what this amp did with only a couple hours of warm up in my system. I spent the better half of the first evening cursing to myself (aka "you gotta be f&%$ing kidding me).
My 41" Sonus Faber Liuto floor standers became 7' tall - something that to this day boggles my mind. Soundstage depth was incredible, but the width (the width, I tell ya...) was on my front porch (like, through the right wall wide) and into my kitchen through the left...it was all enveloping, and key aspects of performer orientation were delineated in a way where you could hear how many feet apart the artists were from each other and "around them as well", like no other amp I have ever heard. This is something that you rarely hear done with such authoritative precision and was certainly shocking to the senses of this humble reviewer. Additionally, the stage didn't shrink or collapse under load (complex passages, higher volumes, etc.), it just became a grander version of itself. The 80 watt/ch NSI-G never strained or hardened at volume like some amplifiers do and in my experience higher demand passages, at volume, can collapse the stage and performer orientation dramatically. Not the case here...and truly world class!!
Another strange but beautiful phenomena was how I could actually see in my minds eye Cannonball Adderley's alto saxophone physically manifest itself 8-12 inches in front of the speaker on the classic jazz standard "So What" (Mile Davis Kind of Blue 180G LP reissue) in such a way that you could reach out an grab it! In all my years listening, I have never had "that physical experience" appear before me....pretty incredible abilities....I am really liking the the NSI-G at this point (and dreading the day it will be boxed up again and out of my music room.. ).
Given the adjustable capabilities of the NSI-G, I had to go about testing various combinations of "Tube" and "SS" controls on the sonic picture this amp kept painting. There has been much debate on this forum regarding tube and solid state amplification...an almost religious discourse by those (me included) brave and boisterous souls who will "lay it out there" to defend the indefensible....i.e. where does truth live???? It doesn't take long to ascertain where I stand on the issue, as well as other voices relaying their experiences to the contrary. I went into this review with eyes wide open. I first ran the NSI-G in fully SS mode, listening closely and forming the mind's eye view of the musical landscape. I then moved to a combination of SS and tube compliments and made the same mental measurements. What I can say, is that the controls allow a contour of texture, liquidity, color and saturation - much like you get with types of painting materials. To me, the all SS version was like watercolors; transparent, clear and concise with a see through quality that commanded attention, more so than allowing me to simply relax. Adding more tube, with the SS, moved the sonic fabric more towards acrylic and oils - dense, saturated and beautifully human. The SS + tube mode sounded familiar (a given for me), but at a level of aural articulation I could have never imagined. It was the best of both worlds, yet I could respect the "watercolors" presentation as fulfilling as well....never thought I would say that, but it is true.
In closing, I cannot thank Gilbert, Bob and George enough. Gilbert for continuing to test the limits of design and artistry, and Bob and George for setting the table regarding what they heard (and providing key points for me to evaluate in my rig). I could have developed a 1-line review of the NSI-G...this amplifier is transformational and at the same time brings such an honesty to what it plays, in any mode you wish (tube + SS, SS only, etc.). Is it the best amp I have ever heard...for now, yes!!
Mark
My Sonic Tonic - Act I: AAbGYD NSI-G Review
My Sonic Tonic - Act I: AAbGYD NSI-G Review
Last edited by masluck on Tue May 14, 2019 8:19 pm, edited 2 times in total.
Re: My Sonic Tonic - Act I: AAbGYD NSI-G Review
The system hammered the rest of the review for some reason...will finish it tomorrow...