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Solid-State TUBES !!
floobydust:
Leader LSG-11 converted to solid state back in 1970. The wheel must be reinvented lol. It does run off a 9V battery now instead of mains.
If you left it with tubes but go from selenium to silicon rectifier, I end up adding a zener like 150V or 200V 5W to keep B+ from going too high. Or resize the 3kΩ resistor.
b_force:
I don't understand the whole negative and snarky vibe in this topic?
After a week of working with all kinds of micro's, DSP and multi-layer boards, I sometimes like to dive into some tube circuits, old tube radios and builds as well.
Why?
Because it's simple, straightforward and you can basically draw out an entire circuit on the back of an envelope.
You can also assemble and work on it on the fly basically, without having to stare at a monitor screen for hours.
The mechanical structures just looks a lot better than an unknown blob of something on some kind of multi layer PCB.
Is it "better", more efficient etc? No of course not!
It's just pure interest and fascination of technology and history in general.
For the same reason I have also converted solid state circuits to tube sockets, just simply to match the look-and-feel of the whole device.
Not everyone who works with tubes/valves is a total audiophool lunatic.
And still, what if someone is?
The very vast majority of engineers have a oscilloscope and DMM/benchmeter that they purely bought for kicks, specs and looks.
Most people don't even use 1/100th of the capabilities or barely know of all its functions.
In fact, I know and have seen many people who don't even use them at all!
Other people buy a fancy car, sofa or motor bike for no particular reason.
Same thing, just different.
wraper:
--- Quote from: b_force on August 14, 2023, 11:26:02 am ---I don't understand the whole negative and snarky vibe in this topic?
--- End quote ---
It's about making a stupid drop in solid state replacement for tubes rather than tubes as such.
floobydust:
It was already tried with Fetrons, look at the claims of millions of $ to be made in telecom swapouts.
Teledyne Fetron (late 1960's) but they flopped due to price, crazy expensive. I thought ~12x the price of a tube. It's too bad, the ENIAC surely could have used some ;) There were some HP400 and Tektronix 500 CA series upgrade kits too.
It may have been the high labour costs in making them, or the price point was too greedy I'm not sure.
Example inside they used 2N4881 HV JFET's 300V TO-5 IDSS 0.4-2mA along with a small 2N3823 for the input. JFETs from Teledyne (Amelco databook).
Today, you can find HV depletion-mode MOSFET's by IXYS to 1,700V. If that's your thing.
In winter time I get 100% efficiency with tube gear heating my house ;)
EPAIII:
The idea has been around for quite some time. It probably started with rectifiers.
The big problem is they don't heat the room in the winter like real tubes do. Or in the summer for that matter.
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