I am happy to announce that I finally got around to finishing the article “Beast With a Thousand JFETS” and it is posted HERE. Those of you who have seen the coverage of the 2011 Burning Amp Festival have wondered what the hell that was in the photos, and now you can see it with more detailed design information so that you can dream of making your own.
The F6 article has also been posted HERE on this site as well as 6moons. The amplifier is sufficiently unique and pleasing that I have decided to go ahead and make a few available for sale. If you want one, keep an eye on this page for the announcement.
And there are whales today.
The design of the F6 is complete, and was the subject of a talk at the Burning Amp Festival last month in San Francisco. The edited transcription of that talk can be found HERE on 6moons, and will appear on this site later on.
At this moment plans to produce this in quantity have not solidified, although I will build a few, even if only to use as a reference amplifier. Even if you can't buy it commercially, the article contains all the information you need to build it yourself, and I also refer you to the F6 thread on www.diyaudio.com
Sad to relate, SemiSouth, the manufacturer of Silicon Carbide (SiC) Jfets and SIT devices has announced that it is closing its doors. Fortunately for First Watt, I have a large inventory of the parts used by the J2 and the SIT-1 and SIT-2 amplifiers. These products will continue to be made, and there are plans for new product in the future using this technology.
B4's are shipping. You can access information from the link: B4 Manual
The F6 is still waiting for the smoke to clear, as is the Beast With a Thousand Jfets and some new unmentionables...
SIT-1's and SIT-2's are shipping. The first run of each is going to the U.S. and Japan, and sales will expand to the rest of the world in the second runs.
New article being posted today, the F5 Turbo
The F6 design is done and I'm listening to one, but the article will have to wait a little bit.
Also, the SIT-1 and SIT-2 amplifiers are approaching the end of the production line. More information on these will be posted shortly. B4's are also in production and will follow on the heels of the SIT amplifiers.
My son and nephew have gone off to pursue their own careers, so it's just me. I'm old and slow, so you'll just have to be patient...
Seems like yesterday, but as I type this I note that it's been a year. Oh well, I'll try to make for it with lots of new announcements.
The explorations into SITs (Static Induction Transistors) that began with a custom fabrication for me by SemiSouth in 2010 have begun to bear fruit. Two designs have emerged which will be made available shortly. I have written an article on these devices which will appear in the next issue of Linear Audio magazine ( www.linearaudio.net ) and also a shorter introduction on the subject that you can read: SIT intro. This can also be downloaded as a pdf file: SIT intro.pdf
The SIT-2 put in an appearance earlier this month at two audio shows in Japan. The result of over a year's work with the SIT transistors, this stereo amplifier delivers exquisite audio with single-stage single-ended Class A operation without feedback or degeneration. They are in production now, and will be available for purchase in January.
Also displayed in Japan, the SIT-1 is a mono-block version of the same amplifier with an even more severe aesthetic – the SIT is the only semiconductor in the circuit, surrounded only by resistors and capacitors. It features a user adjustable operating point which helps to optimize the performance for individual loudspeaker characteristics. This amplifier is beginning production and will appear late January.
At long last, the B4 will be available for sale in January. This is the adjustable electronic crossover which delivers 6,12,18 and 24 dB/octave slopes and is adjustable from 20 to 1260 Hz in 20 Hz increments and 200 to 12600 Hz in 200 Hz increments. DC coupled Jfet buffers with no feedback give 0.001% distortion and bandwidth from DC to 500 Khz.
The B2 is finally in also production. This little box is a must-have for people who are serious about using dual amplifiers (bi-amping) to drive loudspeakers through their passive crossover networks. It has a very high input impedance and a low output impedance and allows wide adjustment of the relative levels of the low frequency amplifiers versus the mid/high frequency amplifiers.
F5 Turbo – The F5 already has a reputation for delivering current into lower impedances. Can you imagine an F5 with a supercharger on the output stage? This DIY mega-update to the crowd-pleasing F5 will appear here and on-line in time for Christmas.
F6 – A new and unusual Jfet amplifier design using a unique feedback mechanism. Ten units will be produced and the design will be posted for DIYers. Expect this at the beginning of 2012.
Do I look tired? Happy holidays.
Copyright 2011 General Amplifier