LaoCao SIT Tests

[Nelson Pass]

A couple months ago I received some samples of the SITs from LaoCao in
China which are also being discussed in the thread

V-FET (SIT) amplifier production

I have some results of testing:

Attached are a diagram of the test setup, and the results of distortion vs
output for that setup expressed as output volts and also equivalent output
watts (as if it were driving a power amplifier follower stage).

In this case the bias figures were chosen to null the second harmonic.

Lowering or raising the output DC figure will increase the second harmonic.

The gain without feedback or degeneration is 36 dB, leaving plenty of
margin for feedback.

The output impedance is about 360 ohms.

In this setup the bandwidth is - 3dB at 200 KHz with the input seeing a
total source impedance of 400 ohms.

 

[Zen Mod]

F6-like FE feeding F4-like OS ....... with some serious SE bias ....

 

[Michael Rothacher]

Pretty neat. Wish those had been around when I did Ironamp.

Thanks, Nelson

 

[buzzforb]

F6-like FE feeding F4-like OS ....... with some serious SE bias ....

 

[kasey197]

The tube guys really need to see this !

If Kiven is right, we may be able to get these parts before too long.....

 

[L CAO]

Thanks, Nelson

 

[lgqliu]

 

[hitsware]

> The tube guys really need to see this !

What tube does it emulate best ?

 

[Nelson Pass]

Thanks, Nelson

No, Thank You.

 

[kevinkr]

> The tube guys really need to see this !

What tube does it emulate best ?

Some of us are watching. The curves appear quite triode like, as to what it emulates I can't say.

 

[cwtim01]

...

Please excuse me for asking, but I find it difficult to imagine how Lao Cao, a company that mainly make speakers, get into the semiconductor business. I guess the investment required to get the equipment and the skills would be huge, and I can't imagine how many VFETs you need to sell in order to break even ...

 

[indra1]

Considering the skyrocketing price of the nos SIT, no one offering current production, and the stir from Firstwatt SIT1, Sony VFET anniversary etc., I think the LCao SIT introduction is nicely timed. Priced moderately, a lot of amp manufacturers and kit makers will be interested.

 

[buzzforb]

When we will know about availability?

 

[vdi_nenna]

Considering the skyrocketing price of the nos SIT, no one offering current production, and the stir from Firstwatt SIT1, Sony VFET anniversary etc., I think the LCao SIT introduction is nicely timed. Priced moderately, a lot of amp manufacturers and kit makers will be interested.

What's the price?

 

[Michael Rothacher]

@L CAO. Let us know if you need more beta testing.

 

[Zen Mod]

someone need betabeta tester ?

 

[generg]

I seems I am always to slow…..

but I tell you…. I don't care anymore…..so it seems I am gamma gamma Tester….



right side a small Toshiba…..

 

[Zen Mod]

 

[juanitox]

I seems I am always to slow…..

but I tell you…. I don't care anymore…..so it seems I am gamma gamma Tester….



right side a small Toshiba…..

i' v got a pair of these , but only this schema to go with do you have another destiny for yours?

 

[Zen Mod]

All roads are leading to Rome