Burning Amplifier BA-1

The one and only
Joined 2001
Paid Member
Eric Weitzman said:
25 watts per channel seems low if the amps are dissipating 300 watts per stereo channel and the output stage is drawing 3.5A at 50V. Where are the missing 100 watts?

They are pure heat. This is a Burning Amp.

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.

:cool:
 
diyAudio Editor
Joined 2001
Paid Member
One of the reasons the board area is pretty tight is that the shorter chassis is very congested inside compared to t he longer one. - Mainly due to fitting in 4 supply capacitors...

I'm not sure if there ARE any short chassis with all 240 output devices..

Nelson states that with Elna Silmic 10uF radial caps it sounds great- now those would be easy to fit!! What other radial caps are there that people might consider?, and what are their lead spacing and size?
 
diyAudio Editor
Joined 2001
Paid Member
The boards are in the final stages of design. Cviller has posted them so that he can get feedback from other members.They will be produced by diyAudio as a fundraiser. There won't be any power supply boards in this buy. The main purpose of power supply boards is to connect a bunch of "snap-in" caps, and allow use of discrete diodes rather than diode bridge blocks. They really aren't necessary for the people with the chassis, which have large "computer grade" caps and bridge rectifiers installed. BUT many other power supply boards will work. The ones produced for First Watt amp clones such as the F5 will work, possibly with some modifications.

Cviller has some, as does Peter at Audio Sector. The main purpose of power supply boards is to connect a bunch of "snap-in" caps, and allow use of discrete diodes rather than diode bridge blocks..
 
I post again here what I wrote few days ago on "Aleph J schematic" thread:

I think that some of the new features intruduced in the BA1 front end schematic colud be applied in the Aleph J too.
I'm referring to the RC filter (R210 + C205 and R211 + C206 on BA1) useful to isolate and clean the PS a bit and to drop a Volt or so to keep the input fets well within their safe voltage range and to the CCS made by a 2SK170 instead of the ZTX550 (Q2 on A-J) plus the (noisy) zener, capacitor (C4) and dropping resistor (R5).
Also R7 could be replaced by a pot as in BA1.
Can we get rid of the IN- coupling cap (C1)?
 
Official Court Jester
Joined 2003
Paid Member
Variac said:
Hey Papa!+ (other zenlike members)
Could I use the BA1 front end as a preamp to use with my F4's?
I guess not near enough gain for full output, but what kind of output voltage are we talking about? Prob needs a regulated supply ?


D+ for pos input of balanced F4
D- for neg input of balanced F4

not full blast , but near enough

isn't easier to make XCCSwhatevercascoded BOSOZ , with altered gain ?
make it with altered positive PSU , and it will drive even bridgedbalancedparalleled F44 ....... :rofl:

ya Kwayzee Mod .......

:clown:
 
Official Court Jester
Joined 2003
Paid Member
massimo said:
I post again here what I wrote few days ago on "Aleph J schematic" thread:

I think that some of the new features.....


re-read answers in AJ thread

both biasing and modulation of output mosfets ,via input LTP , is referenced to neg supply ;

you can't alter any voltage level there without too much fuss .

improving CCS for input LTP is another issue - do what you think is best

look at Babelfish J schematic ;everything is boiled water ...... :clown:

http://tiny.pl/zfgp