Don't most of us already think he is a Guiness 
?
After all, he came up with all this neat stuff!
Isn't it great when those guys do that in unison?
?After all, he came up with all this neat stuff!
Isn't it great when those guys do that in unison?
Looking forward.....
Someone will be the unlucky
one who hits page 666
or
666,666 views
dunno which is more evil ?
Someone will be the unlucky
one who hits page 666
or
666,666 views
dunno which is more evil ?
Long thread
I'm interested in building the amps outlined here, so I started reading from the beginning. I thought I might print the thread to spead up the process, but changed my mind when it turned out to be about 600 pages. Pretty impressive. I'll quess I'll just keep reading away. I'll let you know when I've finally caught up.
I'm interested in building the amps outlined here, so I started reading from the beginning. I thought I might print the thread to spead up the process, but changed my mind when it turned out to be about 600 pages. Pretty impressive. I'll quess I'll just keep reading away. I'll let you know when I've finally caught up.
UrSv said:
grataku said:
I had a chance to measure the power of my Aleph X today. I used 7.5 ohm and 3.75 ohm power resistors, true RSM meter and 200Hz test signal (the amp has input cap limiting the frquency below 120Hz). I was increasing the signal until it clipped on a scope.
Here's my measurements: the power into 7.5ohm was 43W (18V rms) and into 3.75ohm 19.7W (8.6V rms).
My Aleph X is completely stripped unit, without active current gain circuit and the rails are around 15V DC.
Peter,
I take it that you liked the aleph-x better without active current gain. What is the difference in sonics?
Regards.
Jam
I take it that you liked the aleph-x better without active current gain. What is the difference in sonics?
Regards.
Jam
I guess it's about 6A total bias. (16 devices per channel, 0.56 source resistors with voltage drop around 0.4A ea.)
jam said:
There is not that much difference, I expected more. I think it's a bit cleaner sound if I remember correctly.
Where do you get that idea? P=IxIxR, and I is limited by the bias in this amp, so less R ==> less P.
I guess it's about 6A total bias. (16 devices per channel, 0.56 source resistors with voltage drop around 0.4A ea.)
6A total bias = 3A per side
No Active Current Gain
P Average=IxIxR/2
=3x3x3.75/2
=16.875W
So we are pretty close to the mark .... Peter's amp must be running slightly over 6A total bias.
No Active Current Gain
P Average=IxIxR/2
=3x3x3.75/2
=16.875W
So we are pretty close to the mark .... Peter's amp must be running slightly over 6A total bias.
With 560 milliohm resistors and 16 FETs per channel, Peter's amp should be running around 7.14A of total bias on each channel so I think MikeW may have a point. Each output FET should be drawing around 7/8 of an amp with the aforementioned resistance and he should be getting more power into the 3.875 ohm load according to my calculations. Will someone please explain "current gain"?
nania,
do a little search on ac-current-gain and you will find a whole bunch of explanations.
william
do a little search on ac-current-gain and you will find a whole bunch of explanations.
william
wuffwaff
From what I understand the Aleph-X is bridged. The "ac current gain" as you describe it does not apply to this circuit so the bias value is not split in half as it is in the ordinary Alephs. The Aleph-x should deliver and use twice the current of an ordinary Aleph with the same output stage. The bias current is determined by the value of the source resistors used and is optimum when not reduced by any other resistance. Given the description of Peter Daniels mosfet layout, his amp should be stiff to a 4 ohm load (ie: double its output power from 8 to 4 ohms) so something is suspicious about the numbers provided. Is there anyone else reading this thread that can clear this up?
From what I understand the Aleph-X is bridged. The "ac current gain" as you describe it does not apply to this circuit so the bias value is not split in half as it is in the ordinary Alephs. The Aleph-x should deliver and use twice the current of an ordinary Aleph with the same output stage. The bias current is determined by the value of the source resistors used and is optimum when not reduced by any other resistance. Given the description of Peter Daniels mosfet layout, his amp should be stiff to a 4 ohm load (ie: double its output power from 8 to 4 ohms) so something is suspicious about the numbers provided. Is there anyone else reading this thread that can clear this up?