I can't comment on the AV400 but I have built the P101 (low power version) and it is a fine sounding amp..... one of the best I've heard and is very simple in design and to build. Made some comments previously.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=33189&highlight=
Could always ask some questions at the ESP forum.
http://www.instantboard.com/users/rode/
Yeah, it can be hard choosing an amp project as you don't know what you are going to end up with. Nothing worse than spending all that time and money and not liking the sound....... happened to me once and it is extremely disappointing.
Good luck.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=33189&highlight=
Could always ask some questions at the ESP forum.
http://www.instantboard.com/users/rode/
Yeah, it can be hard choosing an amp project as you don't know what you are going to end up with. Nothing worse than spending all that time and money and not liking the sound....... happened to me once and it is extremely disappointing.
Good luck.
It depends what kind of sound you want. I have a pair of the amp now called AV400, and I've listened to some other decent DIY amps including two of Rod Elliott's designs, but not the P101 so I can't comment. The AV400 specifically has an effortless sound with an unusual weight behind the bass. It sounds very clean and significantly improved the dynamics of my speakers compared to any other amplifier I have tried. The other amps all sounded similar but the AV400 seemed to bring the speakers alive in a different way. Because of that, I continued to use it despite it not having the magic or detail of the good Class A amps. I have no idea whether it is better or worse than the P101.
Edit - I should qualify that by saying that while I don't need so much power that my amplifiers would clip, the AV400 is way more powerful than anything else I've tried.
Edit - I should qualify that by saying that while I don't need so much power that my amplifiers would clip, the AV400 is way more powerful than anything else I've tried.
Another idea.
Use the AV800 design.
Differential inputs, not sure about the AV400.
Use a smaller transformer to scale the power down
for you needs, perhaps use ~70 volt rails instead of 90v.
Use less output stage transistors, maybe 3 or 4 instead
of 7 per rail.
Then if you do want more power later, you can always
modify the design again.
Use the AV800 design.
Differential inputs, not sure about the AV400.
Use a smaller transformer to scale the power down
for you needs, perhaps use ~70 volt rails instead of 90v.
Use less output stage transistors, maybe 3 or 4 instead
of 7 per rail.
Then if you do want more power later, you can always
modify the design again.
I’m also trying to decide between the ESP P101 or Aussie Amplifiers N-Channel Power MOSFET Amplifier. Both designers have built many amps in there day and both designers are claiming that this is one of there best. Both these amps use the same rail voltage (-+70 I think I’ll drop it down to 65 so I can use the 80v rated caps) so a can build one channel of each using the same PS and see which I like best. If anyone has had a chance to try these amps please post some comments.
If they where to sound both the same, it’s still a hard pick. The N-Channel amps mosfets cost only 1/3 the price. But the ESP P101 is probably more stable over time, that is to say it has less funny thermal stuff going on.
If they where to sound both the same, it’s still a hard pick. The N-Channel amps mosfets cost only 1/3 the price. But the ESP P101 is probably more stable over time, that is to say it has less funny thermal stuff going on.
OK I think I'm going to go with the AV400's
Anyone known why Anthony is hard to get hold of??
I got I reply out of 3 or so emails......oh well.
I'd better ring him......
The plan is 5xAV400's in mono block config
+ either a AV800 or his 1kW mother for the subs later on.
I'll start a new thread with some pics of planned case designs etc
hope in the next day or so.
If you're out there Anthony I like some advise.
cheers
Anyone known why Anthony is hard to get hold of??
I got I reply out of 3 or so emails......oh well.
I'd better ring him......
The plan is 5xAV400's in mono block config
+ either a AV800 or his 1kW mother for the subs later on.
I'll start a new thread with some pics of planned case designs etc
hope in the next day or so.
If you're out there Anthony I like some advise.
cheers
three people???? 
but anthony did mention that it is his best selling amp?
it has been months since I did the listening test to that amp so I'll just post what I remembered........
in the P3A, I used 25V 225VA toroid, 6800uF per rail per amp, and no protection, muting etc.
in the N channel amp, I used 500VA dual 48V toroid with 20,000uF (two 10,000uF caps) per rail per amp with fan cooling, speaker protection, muting etc.
(you don't want to dump 70 volts DC into your voice coil. )
the N channel amp sounded quite clean at high volume but not as clear with the treble of the P3A, but it has a good grip to any speaker/subwoofer I connected it to. it can pump out enough power to squeeze out loud sound to even the most inefficient speakers. I have not done an extensive listening test since I'm only using it to power my stereo subs. if I have the time, I might do another test and post some more comments.
but anthony did mention that it is his best selling amp?it has been months since I did the listening test to that amp so I'll just post what I remembered........
in the P3A, I used 25V 225VA toroid, 6800uF per rail per amp, and no protection, muting etc.
in the N channel amp, I used 500VA dual 48V toroid with 20,000uF (two 10,000uF caps) per rail per amp with fan cooling, speaker protection, muting etc.
(you don't want to dump 70 volts DC into your voice coil.
)the N channel amp sounded quite clean at high volume but not as clear with the treble of the P3A, but it has a good grip to any speaker/subwoofer I connected it to. it can pump out enough power to squeeze out loud sound to even the most inefficient speakers. I have not done an extensive listening test since I'm only using it to power my stereo subs. if I have the time, I might do another test and post some more comments.
pictures are on my website. the devices don't get hotter than 70°C in my case. I just couldn't fit a bigger heatsink in my rack mount case.
the picture in my website is about several months ago. before I did a major redo last week. I moved the powersupply caps, taking the option of wind tunnel cooling if I ever get the time and money to do it. the amp also now uses 4 pairs of output stages per channel (I'm using the original design which used three pairs) but unfortunately, I don't have pics to show yet.
amps (the "2400" amp...2X 400 watts)
the picture in my website is about several months ago. before I did a major redo last week. I moved the powersupply caps, taking the option of wind tunnel cooling if I ever get the time and money to do it.
the amp also now uses 4 pairs of output stages per channel (I'm using the original design which used three pairs) but unfortunately, I don't have pics to show yet.amps (the "2400" amp...2X 400 watts)
I just want to point out one thing.
If you buy from anthony at http://www.aussieamplifiers.com/ just remember, support from him is sketchy at best, for a few years he was unreachable then he came back here for a short time with apologies and offered renewed support, after about 2 months he is non responsive again, his last post was 02-26-2004 07:23 PM but he was last on DIY 07-14-2004 02:59 AM.
I am not saying anything bad toward anthony just stating some facts, if you buy his amplifiers be prepared for ZERO support.
I am building two of his AV800 boards and after finding some problems with the PCB I am a little worried about firing it up for the first time, I should be "turning it on" for the first time sometime in August. I can't wait to post my results with pictures here!
BTW my avatar is a populated AV800 PCB
If you buy from anthony at http://www.aussieamplifiers.com/ just remember, support from him is sketchy at best, for a few years he was unreachable then he came back here for a short time with apologies and offered renewed support, after about 2 months he is non responsive again, his last post was 02-26-2004 07:23 PM but he was last on DIY 07-14-2004 02:59 AM.
I am not saying anything bad toward anthony just stating some facts, if you buy his amplifiers be prepared for ZERO support.
I am building two of his AV800 boards and after finding some problems with the PCB I am a little worried about firing it up for the first time, I should be "turning it on" for the first time sometime in August. I can't wait to post my results with pictures here!
BTW my avatar is a populated AV800 PCB
Leve,
The IRF Mosfets are sort of picky about thermal stability when used in high power Class AB output stages like these. So it is very important that you mount the Vbe multiplier device directly on top of one of them, and also match the devices to within a couple hundredths of a volt Vgs. If you don't do this then you can get some spectacular failures due to thermal runaway as many of us have. Otherwise the amp works fine and there is no problem with Anthony's design, even for abusive continuous power.
The IRF Mosfets are sort of picky about thermal stability when used in high power Class AB output stages like these. So it is very important that you mount the Vbe multiplier device directly on top of one of them, and also match the devices to within a couple hundredths of a volt Vgs. If you don't do this then you can get some spectacular failures due to thermal runaway as many of us have. Otherwise the amp works fine and there is no problem with Anthony's design, even for abusive continuous power.
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