Burning Amplifier BA-2

[Variac]

Here it is! The new Burning Amplifier BA-2.

The second Nelson Pass design in the Burning Amp series. This one is a complementary output amp that uses much of the gain circuitry from the previous single ended BA-1.

I really enjoyed Nelson's detailed explanation of how it works, and how in even greater detail than before he answers the perennial questions "How hot is too hot?" "How to avoid a literal burning amp by firing it up correctly," and "How some design decisions affect the sound".

Finally, he gives us hints as to how the design can be adjusted and varied even by those of us who aren't experts. I'm getting all kinds of ideas and you will too. You don't need to have gotten a gift chassis from Nelson at the Burning Amp Festival in order to make a Burning Amp, just this article....

Mark

[gagnou]

Hi Mark,
There's a slight omission I believe.
Connection from the Vbias to the gates of the output mosfets is missing from the output stage schematic.
Regards,
George

EDIT: We have corrected the article END EDIT

[Zen Mod]

like this .........

btw - Papa just giv'sya basic of output stage of XA amps ( at least my small , often hurting , brain alarms on that ....... )

[Zen Mod]

Papa wrote :

Get over it. **

[Zen Mod]

for lazy boyz

[Zen Mod]

whazzat with Spoiled Kids ....... ?

new Forum scheme is preventing them for spotting New Candy ........

[Variac]

Because the front ends are the same for the BA-1 and BA-2 with only a slight difference, we are pretty committed to making the front end boards for both amps the same, and then two different types of bias boards, one for the BA-1 and one for the BA-2. With this type of layout you can also have the Burning Amp Gain Stage (BAGS) in a separate box as Nelson mentions. He also hints that the BAGS will work with some future BA amps......

I'll be interested in some power supply designs for the gain stage. Is a Shuntie a good idea? I'm sure we will hear..

Nelson had mentioned that they would be similar so we decided to wait before continuing on board developement. Cviller is starting the revised layout right now..

Mark

[Zen Mod]

Originally Posted by Variac

....
I'll be interested in some power supply designs for the gain stage. Is a Shuntie a good idea? I'm sure we will hear..

......
Mark

well - I have slight impression that Shunty isn't adequate from two (or more ? ) reasons :

one is that probably not entire BA population will be capable ( or just patient enough ) to solder and activate damn thing ,
second one is that Papa isn't so keen on kwayzee shunt regs ; not that he can decide instead of anyone what is good for your own amp , or not ..... but this playground is certainly his Oyster .....
third one - something as Shinyy or any other recently here discussed (semi-complicated and just halfasShuntyoverkill ) shunt reg will suffice , both sound and tech wise ......

edit :

there is always possibility to use old approach - just let da bloody thingie bleed ..... connecting some 25W shunting resistors across FE PSU

[udailey]

Foghorn Leghorn... nice!

[Melon Head]

Thanks again Nelson.