R9 too big. Eats up more voltage than the bootstrap saves. Yeah, the gain goes thru the roof with a small Re on Q1, but it’s supposed to. Gain can be dropped back down by adding feedback back to the base of Q1 from the speaker output.
Hell with it. Time to stop beating the dead horse.
Hell with it. Time to stop beating the dead horse.
It would be the better choice because it is only one step. A follower sounds great, but the often necessary voltage amp stage adds impurity and audible distortion (noise).
I would use 2 n-channel mosfets.
No bootstrap in this way. Has nothing to do with audio engineering, audio electronics. That is woods and lawns engineering only;-)
The cap you think is a bootstrap cap (it isn't as you have it configured on a design like this) is actually killing the performance. Your circuit can achieve this without it.
The low supply voltage and FET's like these are a not a good combination tbh.
i also talked about lowering the voltage to 15V compared to the 34V, if the ZCA could make 5W without any additional gain stages this thing should be able to make the 5w at 8 ohms and 10 watts at 4 ohms without any problem.
and while i know it isnt that much power, i think it should be fine for near field applications such as a pair of speakers on my desk.
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Audible dynamics and volume and power have no relation to any power and load specifications. The quality of the parts is decisive: cleanliness and clarity. However, only about one of 10 transistors is suitable for audio in this respect. The IRF140, IRF240 are not audio transistors)-;
Build this amplifier with these, then go to TO-220 MosFets, then try TO-220 bjts. And by the way, make sure your speakers are clean and clear;-)
Build this amplifier with these, then go to TO-220 MosFets, then try TO-220 bjts. And by the way, make sure your speakers are clean and clear;-)
Mr. No, please take the above with a grain of salt (or the whole shaker). Continue with the simulations and building, to discover for yourself which statements are true.
BTW, IRFP240 and IRF240 have exactly the same guts inside.
BTW, IRFP240 and IRF240 have exactly the same guts inside.
im going back home and i picked up an 22ohm 5w resistor for the headphone amp and an irfp9140 for the complementary setup.
And if you wanted to keep it simple, and get the most out of it, I’d be looking at the ckt in post 42. The upper is a P channel, though, but one can obtain pretty much the same performance using a bipolar CFP for the current source. If you have a PNP small signal and power NPN capable of 15W on the heat sink, there you go.
The bootstrap idea properly implemented would overcome the voltage loss in the follower configuration, but without the schade feedback applied in #42 it won’t be well behaved. Mooly’s compromise in #46 surely works well, but doesn’t overcome the voltage losses. It may not be a big deal, but throwing away 3 volts out of 15 sticks in my crotch. Might not stick in yours, but since you started with an auxiliary supply I thought it might. As a learning exercise I’d still build it if I were you. Then go on the warpath for lateral mosfets with the lowest possible Vth. If you do start playing with lateral mosfets you will probably like them better for audio than old legacy hexfet types or anything modern. If you thought the IRFP240 was “unsuitable for audio”, wait till you try a 600W 200A type meant for solar inverters, and have it BLOW UP in your little 5 watt amp. Talk about a WTF moment.
The bootstrap idea properly implemented would overcome the voltage loss in the follower configuration, but without the schade feedback applied in #42 it won’t be well behaved. Mooly’s compromise in #46 surely works well, but doesn’t overcome the voltage losses. It may not be a big deal, but throwing away 3 volts out of 15 sticks in my crotch. Might not stick in yours, but since you started with an auxiliary supply I thought it might. As a learning exercise I’d still build it if I were you. Then go on the warpath for lateral mosfets with the lowest possible Vth. If you do start playing with lateral mosfets you will probably like them better for audio than old legacy hexfet types or anything modern. If you thought the IRFP240 was “unsuitable for audio”, wait till you try a 600W 200A type meant for solar inverters, and have it BLOW UP in your little 5 watt amp. Talk about a WTF moment.
Be careful of 9140’s. They were discontinued years ago and as such the fakers have been running amok with them. 9240’s otoh, are still around from original sources. Non-IR second source parts may be ok, but might not. It’s a risk everyone takes unless they’re willing to pay full price for everything, buying only new production of current parts, though the big worldwide distributors.
they probably are fakes or new old stock. theyre mismatched too but i dont care i just want to see if it works
I think ill built it. Im now intrested in the input filters or where to add the volume control.
Might as well just built the classic John Linsley Hood 69 circuit.
straight forward good performer
What most start with, and more than good enough to " find out"
Way better than many circuits around here that meet approval.
But not much worse than the point to point silly circuits you see on youtube
Also plenty of mods to add a differential input to the hood circuit.
Actually brings distortion down to acceptable levels which then become " unacceptable"
straight forward good performer
What most start with, and more than good enough to " find out"
Way better than many circuits around here that meet approval.
But not much worse than the point to point silly circuits you see on youtube
Also plenty of mods to add a differential input to the hood circuit.
Actually brings distortion down to acceptable levels which then become " unacceptable"