N-Channel mosfet amplifier schematic needed

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#121
rajeev, about anthony's N channel amp, I did build it, it works wonderfully but I doubt its stability. I want something more stable and durable. anthony's N channel amp mysteriously blows up if I plug my bass guitar to my system. and that happens even at low volumes and within a vew minutes of plugging it in.

I still have the PDF file of anthony's N channel amp but I don't think I can post it here. I know it is copyrighted.
 
#122
THANKS LARS

Please suggest the doo,s and dont,s when planning the layout of the output stage !!! what is MOST important ??

As I had written eirlear

" For six mosfets each side in the output , the length of the track on the pcb from the emitters of T12 & T13 to the Gate of the output mosfets will be at least seven inches long on reaching the last mosfet , I hope this will not create any problems however the 100 ohm gate resistor will be nearest to the mosfet ."

What else should I do ??

What will be the temp of the Output devices in the 1000w 4ohm version


Thanks
djQUAN for the reply

I also had made an N-channel amp from the siemens BUZ series application circuit published in Elector years ago , in that some times in idle a mosfet blows , otherwise the sound is very good . I had used Irfp250,s instead of the BUZ mosfets .
 
#123
How many people wants to build the amp?
Maybe one of us (preferably in the states/east, cheaper, right?) will take them to be factory made, produce a small but worthwhile quanitity, and be kind enough to take care of the deliveries?

Are there any other parts that will be worthwhile to groupbuy?

Thanks
Adam
 
#124
Rajeev: It's a bit hard for me to give you so precise instructions for the layout. However it's a quite forgiving design, with 'eat all' (almost) parts requirements.
I suggest you post your layout here in the thread, so we can all try and help you optimize it before you go ahead and build it.

AdamZuf: The price of the amplifier will mainly contribute from heat sinks, transformer and cap bank. The electronics should run you no more than 40-50$ per ch. (1000 W)
 
#127
Lars Clausen said:
Rajeev: It's a bit hard for me to give you so precise instructions for the layout. However it's a quite forgiving design, with 'eat all' (almost) parts requirements.
Click to expand...
It's nevertheless important with a good pcb layout and for a pro it's no problem to achieve this. Half of the performance is the pcb, rest is the design.

Lars, why don't you think of a groupdeal for at least the pcb? I see no problem with that if you run it like that. I vote for a doublesided nice looking pcb with groundplane and plated through holes.
 
#130
n channel amp.!!

Hi Lars.

I still could not get any ans for my previous post.
please do the favour by throwing some light on the amp. I will post my PCB shortly.

I am just going ahead with the board design,I think Single side 90mm x 180 mm should fit in all the components.

1. OOOOps sorry about the Misprint of IRFP640 I meant if I can Use P Channel IRFP9640, for the Higher power of 500w 8 Ohms.

2. Okay GURU!! I think you are right I dont want any oscillation problem ,Will go ahead with BD139/140.

3. With Bias of 50 mA in test what was the cross over distortion for the 8Ohms & 4 Ohms load, Out of curious whats the slew rate of this Amp.

4. I have a toroid transformer which i will be testing with of 1.6 KVA ,55-0-55 AC, whats the power do you think I might get with this.

5. I understand with You & Rajeevs disscusion that I/P GND and the central GND should remain in the same track, Do you Think so!!

6.A good point in adapting of your short ckt Prot from the Milldia Schematic,Can you clarify how exactly to fix as lot of Diys are looking forward for this.

7. Do you suggest on any increase of gate resistors from 100 ohms for high power will this be stable.

Thanks

Arasuk
 
#134
I'm totaly new to the hobby and will build this amp with a professional guy, which I'm supposed to bring the parts to.
I would be glad if someone will be kind enough to help me with a part list for the most powerful version I can make..

Thanks a lot
Adam
 
#136
Lars Clausen said:
Are you guys interested in a complete PCB with all 6 sets of MOSFET's on board, or a smaller PCB with just the low level parts, to hardwire a number of MOSFET's as required?

🙂
Click to expand...
I think it's wise to have as much as possible on one pcb. It's easier to get predictable results. I think also it's wise to start with many output transistor pairs and then scale it down if there is a market for it.
 
#138
LARS
What a wonderful idea , I will plan the output stage and post it soon , you could recomend any changes , and the end result could be useful to all .

Regarding pcb,s I know a guy here who accepts orders in small

quantities say around fifty pcs at a little additional cost , once the design is final I will ask him to give a quote and then if it is viable they can be made .

Rajeev
 
#139
Hi!

Lars and Friends,

Here in India we get good commercial quality PCB at very low costs. We can have it manufactured here in limited qunatity. One time major investment is the films for different layers that need to be made.

Most of my double sided boards are Mumbai / Pune and the finish is very good.

Regards

Rahul
 
#140
Hi lars,

I think complete PCB with all 6 sets of MOSFET's on board will work fine, hardwiring might lead for the osc prob, Espeacially MOSFET's.

The board can be made compact as ,http://www.diyaudio.com/forums/showthread.php?s=&postid=480507#post480507

just an hint for the above.

As rajeev & rahul said we can work for the best possible PCB quality here.

You have to make sure that you adapt short ckt Prot from your "Millennium" amp Schematic,

Thanks

Arasuk
 
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