First Watt SIT amps

[hvbias]

Anyone heard FirstWatt SIT-1 or SIT-2? Nelson is pushing the boundaries of solid state with these cool little devices

How can you not get excited, transfer curves that resemble triodes, but with all the benefits of solid state (low output Z, etc)?

http://www.6moons.com/audioreviews/firstwatt12/1.html
http://www.6moons.com/audioreviews/firstwatt14/1.html

Exciting times, but unfortunately the speakers I like are low efficiency. But this quote by Nelson Pass from 6moons gives me hope they'll make their way into the Pass lineup

"There's more of this sort of thing in the works. With the XP30 preamp Wayne catered to a couple requests - dual sets of outputs independently adjustable for biamping, much lower output impedance and much higher gain options. The latter two make it an excellent front end for an amplifier, providing all I need for various follower output stages. Now I can just cobble them together and listen apples to apples. It's very interesting and illuminating to isolate the specifics of different devices, topologies and so on and trying to correlate them to the subjective side of things. So far there have been a few surprises and I'm hoping there will be more but it's terribly complicated.

"One thing that has helped is that we are now running four sets of Tannoy 15" HPD drivers in Jensen Imperial enclosures all with Joe's special crossovers. They are extremely revealing of the phenomena of interest and this puts our listeners more on the same page so the turn-around time for subjective testing is greatly speeded up. Bigger power is definitely for the future. The Yamaha 2SK77 parts are rated at 300 watts, which would definitely get me into the 75 watt @ 8 category à la Digital Do Main but without the multiple stages, feedback and degeneration. Pricing and availability of that part remain to be seen. Alternatively I can start paralleling SIT-1s but realistically First Watt is not likely to go beyond about 25 watts. Far more probable is that you will see some of these things embedded in the next generation of Pass Labs. When they heard what you heard, my partners acquired a particular gleam in their eyes." - np

 

[cjfrbw]

Modern equivalents of the old VFET amps originally built by Sony and Yamaha in the late 70's/early 80's. I had a Sony TA 5650 for years, use a TA 4650 now in Santa Cruz. I have a TA 8650 that I am trying to repair with my rudimentary DIY skills, long term project.

The Sony VFETs don't have the complete richness of tubes, but the tonal decay/ambience is smooth and natural. Separation of instruments/voices in the sound field are non pareil, even compared to tubes, and detail/dynamics are solid state-like without the solid state tin megaphone effect or the graying/glaring. Depth is three dimensional rather than solid state flat.

 

[AudioBear]

We've been 300B tube amp people for many years, we've tried others but always came back to 300B amps. On a chance listening to a pair of First Watt SIT-1 amps... all that changed. We now own a pair of SIT's and are very happy indeed, they seem to have a more extended treble and bass than our best 300B's but still have that lovely 3D sound stage and smooth detailed mids and highs. Perhaps they just lack a touch of presence compared to valve amps, but if they do we're not missing it

Try them, you maybe pleasantly surprised if you have relatively efficient speakers.