Does anyone know where I can find a PCB layout for the 400W amp here? Has anyone built it or know anything about it?
http://members.tripod.com/valveaudio/schematics.htm
(for those concerned, it has nothing to do with the 7200W project. I'm just building this because I have subs for it, and for something to do. It's a lot more sane, and I'll be building it exacly to specs.)
[Edited by Kilowatt on 12-08-2001 at 01:33 AM]
http://members.tripod.com/valveaudio/schematics.htm
(for those concerned, it has nothing to do with the 7200W project. I'm just building this because I have subs for it, and for something to do. It's a lot more sane, and I'll be building it exacly to specs.)
[Edited by Kilowatt on 12-08-2001 at 01:33 AM]
Looks like he's selling the circuit boards for $5--just buy 'em.
Make sure you can find all the parts before starting. There's some odd-looking stuff in that schematic (at least to one who lives in the southeastern US, I'm sure everything is available at the corner parts shop where this guy lives).
Grey
Make sure you can find all the parts before starting. There's some odd-looking stuff in that schematic (at least to one who lives in the southeastern US, I'm sure everything is available at the corner parts shop where this guy lives).
Grey
I just figured it would be faster and cheaper (not easier though) to etch one than have it shipped from Indonesia. You know it will cost more than $5.00, and I need two of them. I might buy them anyway though if I can't find a layout.
Anyway, I don't see anything too strange in that schematic. Just some resistors, capacitors, diodes, transistors, an one inductor (is that even necessary?, and it's not on the parts list). I can get everything, I've checked.
Anyway, I don't see anything too strange in that schematic. Just some resistors, capacitors, diodes, transistors, an one inductor (is that even necessary?, and it's not on the parts list). I can get everything, I've checked.
Just order the board from the author.His price is very reasonable.Don't expect this design to put out 400W unless your supply is very stiff.Expect the drivers to blow up.They are only rated for +/- 50V.Better yet use MJE15030/15031 for drivers and MJ15022/15023 for the outputs.I'm not sure about the BC numbers.Check and see that they are rated for at least 80V or use MPS8099/8599.C18 should be at least a 250V rated part.C15 and C17 should have something around 22µF in parallel with them.The outputs should have flyback diodes across them.Remember either the bias diode string or the bias transistor must track the temperaure of the output stage.
Yeah, I know, I think it's 400W peak. I might only gey 300 out of it, if that, the math says so. I've taken note on everything else you've said. I would have to mount the bias diodes and/or transistor on the heat sink right? Does anyone know any subsitutes for the BC transistors?
Thanks for the advice
Thanks for the advice
Strange, I don't really know. Maybe it's like how some people like tubes just because. Or, perhaps it's because MOSFETS strike me as being a thing for pros to use, MOSFETS are apparently more picky than biplolars, and they're more expensive, and are static sensitive. Maybe I shouln't prefer one over the other though. They both work fine.
People generally like tubes because they add second-harmonic distortion and produce a "warmer" sound.
I think a lot of the stigma surrounding MOSFETs came from when there was only relatively bad mosfet technology, it was used in badly designed mid-fi gear and as a result didn't sound very good.
Modern MOSFETs as well as modern designs incorporating them are very good.
They're also not necessarily more expensive, but even so, we're not talking a huge total cost difference here.
Static sensitive? Just don't be stupid and its not a problem.
Both have pros and cons but for this particular application there seems really to be no reason to dislike a design because it uses MOSFETs.
That having been said, if you just want to use BJTs, sure, go ahead! Just try not to close out some possible good options because of it.
I think a lot of the stigma surrounding MOSFETs came from when there was only relatively bad mosfet technology, it was used in badly designed mid-fi gear and as a result didn't sound very good.
Modern MOSFETs as well as modern designs incorporating them are very good.
They're also not necessarily more expensive, but even so, we're not talking a huge total cost difference here.
Static sensitive? Just don't be stupid and its not a problem.
Both have pros and cons but for this particular application there seems really to be no reason to dislike a design because it uses MOSFETs.
That having been said, if you just want to use BJTs, sure, go ahead! Just try not to close out some possible good options because of it.
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