It is the thermostat.
Sorta strange that it has insulation around it that would reduce its coupling to the air temperature. Wouldn't you want the thermostat on one or both heatsinks?
I believe insulation is integral in part from factory , at least I've seen them like that
as I understand position - it hangs on air in case , not heatsink
I have two idiot Cats , liking to lay on Papa's Koan M2 even in mid of Summer ....... so, while sinks are hot , innards can become scorching hot
as I understand position - it hangs on air in case , not heatsink
I have two idiot Cats , liking to lay on Papa's Koan M2 even in mid of Summer ....... so, while sinks are hot , innards can become scorching hot
I have a guess as to why he used them:Nelson.
Any sort of prize for correctly predicting this bit?
The laterals have enough tranconductance to do job, have around 0R5 internal resistance, and have a positive temperature coefficient. All of these factors facilitate an amplifier with so few parts.
Yes of course.
I had the same idea 9 years ago for the exact same reason (but without positive feedback).
I prefer simple circuits (I also prefer low gain amps for my efficient speakers), lateral mosfets allow that. They also tend to give lower distortion per Siemen of transconductance. The only reason to want more is for the damping factor, I achieved it through paralleling a pair of devices with an appropriate amount of feedback.
Nelson is brainier so he did it with positive feedback.
Edit: One other thing that can be said for the laterals (at least mine), is they match extremely well, so for the DIYer they may even work out to be cheaper than IRFP240/9240
I had the same idea 9 years ago for the exact same reason (but without positive feedback).
I prefer simple circuits (I also prefer low gain amps for my efficient speakers), lateral mosfets allow that. They also tend to give lower distortion per Siemen of transconductance. The only reason to want more is for the damping factor, I achieved it through paralleling a pair of devices with an appropriate amount of feedback.
Nelson is brainier so he did it with positive feedback.
Edit: One other thing that can be said for the laterals (at least mine), is they match extremely well, so for the DIYer they may even work out to be cheaper than IRFP240/9240
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I know it was just an accidental slip of the tongue. (or fingers in this case.)
Of course we know the cats are much more smarter than we are.
Of course we know the cats are much more smarter than we are.
I'd certainly be happy to reach the status of, slightly dumber than an idiot.
I know it was just an accidental slip of the tongue. (or fingers in this case.)
Of course we know the cats are much more smarter than we are.
fact (by default) that they're smarter than me , is not changing fact that they're two funny idiots
fact (by default) that they're smarter than me , is not changing fact that they're two funny idiots
Bright enough to know that the amp case needs more damping!
And they don't ride motorbikes...much too cold.
I have updated my schematic of post #218 using information gained from the 6Moons photos and everything simulates fairly well.
I estimate the open-loop gain of the jfet and output fet stages into an 8 Ohm load to be 42dB with all feedback removed. This was measured as the V(Out+,Out-)/V(gates,fbnode), where gates is the jget gate node, and fbnode is the wiper of potentiometer P3. With a closed-loop gain of 14dB that means that there is 28dB of negative feedback, which is a huge feedback factor. Perhaps I am incorrectly estimating the open-loop gain, but that gain factor is fairly consistent with the F5.
I estimate the open-loop gain of the jfet and output fet stages into an 8 Ohm load to be 42dB with all feedback removed. This was measured as the V(Out+,Out-)/V(gates,fbnode), where gates is the jget gate node, and fbnode is the wiper of potentiometer P3. With a closed-loop gain of 14dB that means that there is 28dB of negative feedback, which is a huge feedback factor. Perhaps I am incorrectly estimating the open-loop gain, but that gain factor is fairly consistent with the F5.
Attachments
Output FET bias adjustment, similar to the same pots in the F5, but without the additional resistor, thermistor, and current limiter circuit.