Burning Amplifier BA-1

But can anyone help me out on the original questions why adding an aleph current source to just the buffer stage doesn´t work and results in an occilation.

You would need to post a schematic of your modifications before anyone can comment.

You will get a lot more efficiency out of BA#2, which is push-pull instead of single-ended/constant current source.

If you want more efficiency out of the all-N channel output stages, we will expect to be doubling the efficiency in a later version.

As I said earlier, change the topology to a quasi push pull output.
 
Thanks for your suggestion but I do not necessarily want the aleph sound. alltough a newby a big part of all this hassle is because I want to learn and be able to know whats going on in these circuits.

But again not to just build someones (Nelsons) design and then settle with it but to learn, and have fun in the proces of learning.


Buzzforb, Thanks for your input so far and hope that when you suddenly get struck by and idea of how to increase efficiency you will let me know.

I hope someone else out there will be able to answer my questions.:)
 
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Joined 2005
the post you quote by Nelson Pass looks old enough that the mentioned 'later version' could be the relatively new BA-3, which basicly is a new frontend combined with output from either BA-1 or BA-2
and now a bit later cascoded input and additional driver for the turbo charged F5 ... and maybe all variations of going balanced as well

is that the effieciency you ask about ?
 
By having less of its consumed energy being turned into heat..

The only thing I can thinhk of is adding an aleph current source but that didn´t work so far. Maybe some clever trick to have this thing move into class a pp or ab

I realy can´t think of another way but that doesn´t mean much, and certainly not that it will therefor be impossible. ........
 
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Joined 2005
For the moment I hope someone will put me on a track where I can explore further into increasing the efficiency of BA1.

The schematic of how I tried to add an aleph current source wil follow Later

instead of messing up this thread, maybe you better open a thread with your project

and no, I do not have a mod hat on
its not for me to decide what you want

ofcourse its perfectly fine here if other people are interested in your ideas
but if not....you have just presented it, at thats it, and ok too
work on it, come back again and show us what you have
but don't push people if they don't want it

would be perfect to open a thread and show what you are doing, photos, schematics, debate, anything
 
Now I have seen your schematic, I'm not surprised it oscillated, it has positive feedback.

Take a look at the Aleph J, look at the phase of the signal at various points in the loop compared to your cct, start at the output, then at the collector of the bias transistor - ok so far, then back at the output of the FET - oops.

http://www.diyaudio.com/forums/pass-labs/111197-aleph-j-schematic.html

Try moving the connection from the base to the collector.

Also watch the polarity of the cap, it looks like it needs to be reversed.
 
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Hi Namesmeanlittle,
If you will go to firstwatt.com The Power supply schematic is there(also in the store ),so few parts,just make a list.
Mouser and digi-key have parts,Lots of places to get transformers,torrids are prefered.
The output will depend on how you wire them to the speaker or speakers,These amp's push 4 to 8 ohm EZ,
Have fun and do ask in these forms if you get stuck,Take your time!
Regards,
NS
 
thanks
i'm probably gonna make 2 completely separate mono blocks ( i wanted to double outputs thats why i was ohms worried) that match next to each
other with heat sinks on only one side
i wish i had a pic
show you in a couple months when i'm done
add led's and a beaker fans lots of fans so i can run it full
then i'll hook them up to my Sasuie sp 1500's and run it half output like the rest of my system haha.... inside joke