The Av800, how good is it?

Status
Not open for further replies.
Jump to Latest
#62
thylantyr said:
You might want to check your Holton PCB's to make
sure they match the current schematic.

http://www.aussieamplifiers.com/downloads/AV800.pdf

My Holton PCB doesn't seem to have locations
for D3, D4, ZD5, ZD6.. These were omitted from the
layout. The boards I have are at least 2 years old,
if not older. Perhaps the design was updated since
or my boards have some errors.
Click to expand...

ZD3 and ZD4 are also missing from the PCB version 1

Regards

Anthony
 
#63
Isn't this amp similar to the 400w symmetrical amp except with balanced input connection and a Mosfet buffer between the second diff pair and the output stage? I could tell you about the way the sym amp sounds. And I think not many people have built either of those designs... at least, I couldn't find anyone who had done the sym amps until just recently.
 
#68
JasonL said:
Now my questions are is this av800 board good or not. ? has any one actually build a board and powered it up. ?
Click to expand...

Reading the archives - Holton claims that many AV800's
were built worldwide with no reported problems.

/guessing below.
Regarding the missing parts from the AV800 pcb
(D3, D4, ZD3, ZD4, ZD5, ZD6), I have a dim memory
of reading about this in some amplifier book I have
(Self or Slone), these parts are sorta optional, perhaps
signal clamper for catastrophic conditions, should not
interfere with sonics. My memory fails, I would have
to dig it up. /haha

Holton said that he's read the Self book on audio
and perhaps that is where he got the idea from ?

Speculation - I bet Holton added these parts to the
schematic later after the initial pcb's were made because
'it's the proper thing to do' ? /hehe

This is an easy modification to add to the boards.
 
#69
Kilentra said:
Isn't this amp similar to the 400w symmetrical amp except with balanced input connection and a Mosfet buffer between the second diff pair and the output stage? I could tell you about the way the sym amp sounds. And I think not many people have built either of those designs... at least, I couldn't find anyone who had done the sym amps until just recently.
Click to expand...

To be true I did.. my symamp (built some time ago and revamped recently with a bigger PS) suonds very good, powerful and detailed, with a great control in the bass area.

Cheers

Andrea
 
#70
thylantyr,

I ordered the updated AV800 from Anthony and can't wait to build it. I wouldn't want my work stolen, so if I were you, I'd credit his work, because after all, you just modified it, and never did the full design. If I use another person's work in my documented projects, I credit that person, as it is their work, not mine. I am almost certain this amp will sound great. I'd send the layout to olimex, because I like their boards. I sent jwb's DAC board layout to them, and I love the work.
 
#71
emuman100 said:
thylantyr,

I ordered the updated AV800 from Anthony and can't wait to build it.
Click to expand...

Keep me posted on your progress. I'm interested in knowing
if you like the amplifier.


I wouldn't want my work stolen, so if I were you, I'd credit his work, because after all, you just modified it, and never did the full design. If I use another person's work in my documented projects, I credit that person, as it is their work, not mine.
Click to expand...

His name is referenced in my document and his name is on
my pcb layout. 🙂
 
#74
Yes, that was my question as well. My DAC I built does not work. I really really want it to work, but before I pull more of my hair out, I will take a break and build the AV800, as it seems more simpler to build than the DAC.

My question now is about the mains transformer. For stereo operation, a 2kVA toroidal transformer is required according to the construction manual. It says the secondary windings must be 2x 65V, or 130V center tapped. The primary side must be for US mains. I tried digikey and mouser, but nothing, and was wondering if anyone else would know a place to get a 2kVA toroidal transformer with a 130V center tapped seconndary. I figured this would be the best place to ask.

Thanks.
 
#77
Hi

Looks interesting that project.

Im kind of new here, but am planing to build a nice powerfull suround amplifier. I was thinking of the following specs:

4x 250Wrms for speakers
1x 1KW rms for sub

I obtained two torodial transformers in a bargain, so im limited to their voltage/curent for the project. Could you guys give me some advice on which schematics to use (2x av800/2800 for sub?)

The specs of the torodials are:
secundair 230V - primair: 2x 48volt - 1600VA
I have two of thes which i can put paralel/serie

Hope you can give me some tips
 
#79
thx

But i was wondering. I want to make it all in one single case with one single powersuply. And i believe for 1KW u need +/- 100volt. Will the 200W amp be happy with that? How much voltage can the irf's take anyway? Because when its DC im afraid it will be even more then 100volt.
 
#80
DiMenSioN said:
thx

But i was wondering. I want to make it all in one single case with one single powersuply. And i believe for 1KW u need +/- 100volt. Will the 200W amp be happy with that? How much voltage can the irf's take anyway? Because when its DC im afraid it will be even more then 100volt.
Click to expand...

Well your rails would be 68VDC +/-

IRFP244 should work just fine. Your tranny should easily power two amplifiers, you should write to Anthony and see what he has to say.

Regards
 
Status
Not open for further replies.
Top Bottom