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Old 2nd May 2006, 06:55 PM   #1
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Default Aleph-x running, but a little problem

My new Aleph-x are running, everything including offset is okay. They still have too move into their houses. Compared to the aleph 30, instruments are more focused in their shape and position. But and this is my problem, the bass is softer and the midrange is harder and i dont like that. The aleph 30 has more punch and sounds more laid back at the same time. Does someone have sugestions about the bass? Can i decrease the value of the source and output resistors a little without burning the mosfets? I thougth about making a change to 8 outputmosfets like a mod from aleph 3 to aleph 30 which was the solution for me some years ago, but the i have to by 16 mached mosfets and different heatsinks, because they have no space for more than on fet on one heatsink. Is their an easier solution?
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Old 2nd May 2006, 06:58 PM   #2
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2nd pic
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Old 2nd May 2006, 07:07 PM   #3
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This is the phono for a friend, just if you like to see which way i like the stuff to look.
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Old 2nd May 2006, 07:09 PM   #4
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Old 2nd May 2006, 07:24 PM   #5
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3.
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Old 2nd May 2006, 07:44 PM   #6
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Very nice, I like it a lot.
Unfortunately I can't comment on the sound compared with the Aleph30 as I never heard it.
I have no recommendation how to change the X as I think the sound of each amp is different and not easy to alter without a major redesign. Experts opinion of course may vary.

/Hugo
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Old 3rd May 2006, 06:00 AM   #7
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Thank you, Hugo
It would be very nice, if someone has an suggestion how to increase the damping, just a little bit, without the need to implement more outputfets. How do i calculate the source and output resistors, is it possible to change them from 0.22 ohm to 0.2 or 0.18 ohm. The current would be higher and the voltage drop on the source resistors would be lower, right? So the source resistance of the am should be lower and the damping higher. But i don´t know the exact calculation.
Or am i thinking to simple?
Oliver
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Old 4th May 2006, 06:11 AM   #8
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Good morning everybody,
Should i put my question in the aleph builders thread, because i don´t get any response? I´m sure that there are people around, who could give me some suggestions.
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Old 4th May 2006, 06:58 AM   #9
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Oliver,
Among the many, I found two interesting topics related to your question.
Which aleph for the bass and mids?
what are the differences between the different alephs?

So it appears that damping factor is not the crucial part. I'm also not saying that you picked the wrong amp and no small improvements can be made. But again, as you will read, every amp has it's own character and altering it probably will end up in another design.
I'd try playing with the Aleph current source (R12/R34 in Grey's schematic), the feedback resistors, and the resistors from output to the source of the diff pair. Also, I believe that more current (R11/R33) will improve things but then your cooling devices might be a limiting factor.

/Hugo
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Old 4th May 2006, 05:42 PM   #10
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Ah yes thanks a lot,
i will try to reduce the values of r12 and r34 first. As far as i understand the circuit, it is possible to adjust these values for 4 ohm or 8 ohm speakers. As it changes the current gain of the aleph currentsource and 4 ohm speakers mean more current and less voltage. My speakers have 6 Ohm dc resistance and i don´t know the minimum ac values. I will try that and see what happens.
Thanks again.
Oliver
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