Anakchan's post -
Analog Squared Paper Exhibit Table
Now I had planned to stop by Shikada-san's table months in advance 'cos he was going to pick up my TUR-06 for a charging, and power module upgrade. For those who haven't been following the A2P thread, he's effectively a one-man show popping out 2-3 amps a month max as not only does he have the amp to make, he sews the leather casing himself too. And recently he fell ill which put him further behind in his deliveries. So when I met him in May, he already mentioned about the upgrades but couldn't take my unit in for the upgrade until now. As a gift, for his constant attention to me and my unit, I gave him a pair of Lorenz DF91's which were extremely hard to find. I think he was pleased with the gift.
Anyway, something new he's come up with is a small portable amp that's current driven. The SIT Amp stands for Static Induction Transistor and (assuming I understand Shikada-san's translation) is very much triode-like. This amp as he's done it is also a current based amp. As such I fed it into his other mini SS amp which is voltage driven (at his suggestion). I probably should have brought some higher impedance cans with me to try his SIT amp. It sounded impressive but I couldn't tell if it was the SIT or his mini SS amp.
First thought - Lies! Bad translation! Impossible! SITs are out of production.
1 ==> In the 70s Yamaha and Sony released some legendary SIT (V-FET) amps. Very smooth and pleasing sound. I quite like this technology as does an interesting balance between tubes and solid state.
The specialized SIT chips went out of production and that was that. There is strong demand for these amps but since there are no replacement SITs, once they go...
2 ==> But a few years back, an American company called Semi South produced some SITs for military applications and Nelson Pass purchased a small quantity:
Unfortunately Semi South went out of business. So other than Pass' small stash, SITs don't exist.
3 ==> Well, someone has access to SITs. A Japanese tycoon has a side audio business and somehow convinced Japanese industrialists to produce SITs for his Digital-DoMain amps. I understand he is the only audio guy with access to these SITs
4 ==> But...it looks like a Chinese firm may start production this year and has already delivered some early samples
==> This could be an interesting solid state alternative from Analog Squared. Look forward to more news here. Biasing a V-FET amp up moves things more towards class A and improves sonics but energy consumption and heat production move up significantly. This will be a good challenge for a "portable" solution.