400W amp project

Kilowatt · 8th December 2001, 07:20 AM

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]

GRollins · 8th December 2001, 12:54 PM

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

Kilowatt · 8th December 2001, 07:19 PM

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.

jduncan · 8th December 2001, 09:05 PM

It will take a lot more effort to etch one yourself than to pay $5 + shipping and wait for it to arrive from singapore.

Just buy it.

Kilowatt · 8th December 2001, 09:21 PM

Yeah, I guess so, I'd have to use photo-resist boards, which I'd also have to order. I'll just order the PCBs.

How do I figure out at least how much capacitance audio power supplies for class AB amps should have?

[Edited by Kilowatt on 12-08-2001 at 03:45 PM]

djk · 9th December 2001, 12:57 AM

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.

Kilowatt · 9th December 2001, 01:23 AM

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

djk · 9th December 2001, 02:00 AM

This is a pretty straight forward adaptation of a Leach.The MPS8099/8599 are recommended by Leach and will go up to +/- 75V, beyond that you should probably go with 2N5401/5551 which is what Hafler used in this circuit in the DH500.The B649/D669 are OK up to +/- 85V.

Kilowatt · 9th December 2001, 02:17 AM

Thanks, I might get 400W from this thing yet. I don't know what good it would do me though, since my speakers would probably reach Xmax at low frequencies long before then.

blmn · 9th December 2001, 04:14 PM

Kilowatt,

Use some of japanese low power series as described at Douglas Self site (they have higher VCE and good noise characteristics).

regards

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8th December 2001, 07:20 AM	#1
Kilowatt diyAudio Member Join Date: Nov 2001 Location: Harlowton, MT, USA	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]

8th December 2001, 12:54 PM	#2
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	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

8th December 2001, 07:19 PM	#3
Kilowatt diyAudio Member Join Date: Nov 2001 Location: Harlowton, MT, USA	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.

8th December 2001, 09:05 PM	#4
jduncan diyAudio Member Join Date: Nov 2001 Location: Boston, MA, USA	It will take a lot more effort to etch one yourself than to pay $5 + shipping and wait for it to arrive from singapore. Just buy it.

8th December 2001, 09:21 PM	#5
Kilowatt diyAudio Member Join Date: Nov 2001 Location: Harlowton, MT, USA	Yeah, I guess so, I'd have to use photo-resist boards, which I'd also have to order. I'll just order the PCBs. How do I figure out at least how much capacitance audio power supplies for class AB amps should have? [Edited by Kilowatt on 12-08-2001 at 03:45 PM]

9th December 2001, 12:57 AM	#6
djk diyAudio Member Join Date: Feb 2001 Location: USA	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.

9th December 2001, 01:23 AM	#7
Kilowatt diyAudio Member Join Date: Nov 2001 Location: Harlowton, MT, USA	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

9th December 2001, 02:00 AM	#8
djk diyAudio Member Join Date: Feb 2001 Location: USA	This is a pretty straight forward adaptation of a Leach.The MPS8099/8599 are recommended by Leach and will go up to +/- 75V, beyond that you should probably go with 2N5401/5551 which is what Hafler used in this circuit in the DH500.The B649/D669 are OK up to +/- 85V.

9th December 2001, 02:17 AM	#9
Kilowatt diyAudio Member Join Date: Nov 2001 Location: Harlowton, MT, USA	Thanks, I might get 400W from this thing yet. I don't know what good it would do me though, since my speakers would probably reach Xmax at low frequencies long before then.

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9th December 2001, 04:14 PM	#10
blmn diyAudio Member Join Date: Feb 2001 Location: .	Kilowatt, Use some of japanese low power series as described at Douglas Self site (they have higher VCE and good noise characteristics). regards