You had better re-read that post! The Aleph series outputs are not configured as followers.
Steve
Steve
Oh, and BTW...
I'm not trying to start an argument here. I just think that the Aleph X rail voltage is too low. Put another way- I believe that even though the circuit will work with 15V rails, there will be improvement sonically by using higher rail voltages, particularly when using multiple output pairs, and at higher frequency. Maybe with efficient speakers where the amp will not be operated anywhere near clipping this point is debateable.
Steve
I'm not trying to start an argument here. I just think that the Aleph X rail voltage is too low. Put another way- I believe that even though the circuit will work with 15V rails, there will be improvement sonically by using higher rail voltages, particularly when using multiple output pairs, and at higher frequency. Maybe with efficient speakers where the amp will not be operated anywhere near clipping this point is debateable.
Steve
Please excuse that glaring error... I must not of been thinking straight when i posted that (it seems that lately i do 1/2 my posting when i'm 1/2 asleep ... hmm probably not the most ideal situation)
Ok yes it's hard to completely circumvent this problem given the Aleph topology but if you keep the input to sensible limit and play with the gain a little, you end up with a similar result.
We lose a few volts in the current source so maybe 24V p-p output swing is about right with 15V rails...
Anyway, it's almost 2am here... time for sleep.
Ok yes it's hard to completely circumvent this problem given the Aleph topology but if you keep the input to sensible limit and play with the gain a little, you end up with a similar result.
We lose a few volts in the current source so maybe 24V p-p output swing is about right with 15V rails...
Anyway, it's almost 2am here... time for sleep.
Iwahn,
I HAD a dream!
So, if I use six transistor-pairs at the outputs I only hear a absolutely amasing bass. 😀
When you doubled the transitor-pairs what voltage rails and current did you use?
I HAD a dream!
So, if I use six transistor-pairs at the outputs I only hear a absolutely amasing bass. 😀
When you doubled the transitor-pairs what voltage rails and current did you use?
MEnsing,
I have tried running this circuit both single-ended and balanced with good results, I tried to double the transistors on the output mostly for sharing the load over more devices. The PSU is +/- 15v.
I have tried running this circuit both single-ended and balanced with good results, I tried to double the transistors on the output mostly for sharing the load over more devices. The PSU is +/- 15v.
skaara said:
And there are still 2 wires going to the speaker: one is positive, the other negative.😉 There is no ground connected though.
Oh, I didnt thinked that way🙂 There are normal and inverted phase, so when one is going up, the other is going down and there is 0v on out?..🙂
There is an in phase output and an inverted phase output but no ground ... what happens is that one terminal goes -ve when the other goes positive so there is twice the voltage swing across the speaker compared to if you are there was in phase and ground outputs or inverted phase and ground outputs to the speaker.
skaara said:
bridged amps only ... normal amps eg. alephs, zen and and most amps out there etc have either noninverting and ground outputs or inverting and ground outputs.
yeah, but it's a whole lot more than that... It has a special feedback arrangement that allows distortion from both halves of the output to cancel at the speaker. This is patented by Nelson Pass, in case you didn't know. Another really cool idea by Nelson that he is willing to share with us DIYers.
Im wondering if there will be any aleph x amp or preamp project posted on passdiy website, because if u got aleph x u need x preamp too and opposite..
There wont be an alephx project on passdiy anytime soon because Nelson has only just started selling them commercially.
Why don't you check http://www.passlabs.com/ and see the latest word.😉
X Series amps are different from XA series amps.
X Series amps are different from XA series amps.
XA class a with susy.
X amps go push-pull at some wattage, but they still use susy.
When original schematics are given to us ill made one..
X amps go push-pull at some wattage, but they still use susy.
When original schematics are given to us ill made one..
Maybe this question is asked before I could not find anything about it.
The commercial XA-200 uses 32 output devices (IRF244) and the Mosfets are running at about 20 - 21 W each.
Why is the dissipation per output device so low?
When I read some threads about the Aleph 2 I understood that decreasing the bias current (and therefore the dissipation per device) results in a better sonic performance.
Why not use;
28 devices -> 23 W per device
24 devices -> 27 W per device
The dissipations per device as mentioned above are still very reasonable in combination with good heat sinks.
The commercial XA-200 uses 32 output devices (IRF244) and the Mosfets are running at about 20 - 21 W each.
Why is the dissipation per output device so low?
When I read some threads about the Aleph 2 I understood that decreasing the bias current (and therefore the dissipation per device) results in a better sonic performance.
Why not use;
28 devices -> 23 W per device
24 devices -> 27 W per device
The dissipations per device as mentioned above are still very reasonable in combination with good heat sinks.