Alternative Active Current Source for Aleph-X ?? - diyAudio
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Old 26th August 2008, 09:05 PM   #1
EUVL is offline EUVL  Europe
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Default Alternative Active Current Source for Aleph-X ??

After half a bottle of Bordeaux, I am probably not entire in sane.
So I hope Nelson would forgive me for messing around with his creations.

Following the ideas published in :

Some other Source Follower COnfigurations

Here are a couple of equivalents which could be applied to an Aleph-X or Zen-2 like circuit.
Values are approximate, only to demonstrate principle.
Only output stage shown.

I hope there are no grave mistakes.


Patrick
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File Type: pdf alternative cs for aleph x.pdf (47.9 KB, 407 views)
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Old 28th August 2008, 06:29 PM   #2
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Added a third variant which is sort of hybrid of the Taylor Current Source and the CSA Current Source, removing the current sensing resistor from the output signal path. AND no loop feedback.


Patrick
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File Type: zip alternative cs for aleph x v2.zip (79.9 KB, 99 views)
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Old 28th August 2008, 06:57 PM   #3
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PS

This current source can be easily adapted to allow the use of LU1014 as the power device in the current source. Just reduce the current source above the 2SK170V by about 4mA.

Hannes !!


Patrick
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Old 29th August 2008, 12:46 AM   #4
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Thanks for sharing, Patrick (also the other thread, too).

This Taylor source was new to me...

BTW: I reattached the last document as a PDF instead of zipped .DOC, and without blanks in the filename (both might cause problems -- with my system the latter does).

- Klaus
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Old 29th August 2008, 04:26 AM   #5
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My own favourite is the third one, which is not Taylor.




Patrick
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Old 29th August 2008, 07:08 AM   #6
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Hi Patrick,

thanks for the hint!!

A very cute thing, such an all jfet "Aleph" (if one ignores the cascodes for a moment).

It's a pity, I just have the wrong speakers for that beauty. Some high impedance, high SPL speakers would be best, due to low damping factor and way lower distortion at high impedances.

To get the output impedance down, you can just crank up negative feedback, which was not the point of the exercise

Also the stupid resonances in the frequency response should be taken care of by a more sophisticated mind, I can't imagine that adding a Zobel is the last word on that.

Anyway, that amp will be stored and revived when the right speakers come

Have fun, Hannes
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Old 29th August 2008, 10:54 AM   #7
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You should build it with 16 LU1014s per channel.



Patrick
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Old 29th August 2008, 11:42 AM   #8
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2 sets of 8 matched jfets

times 2 for the other channel...

Yes this is something to dream about

Keeps you warm in winter.

Have fun, Hannes

PS: I'm toying with a ClassB amp at the moment - I know, I know close to blasphemy here
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Old 29th August 2008, 03:24 PM   #9
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> Yes this is something to dream about

What's the problem?
They are still available in Germany.
There are enough people who have built 100W AX's.
16x LU1014 will just fit the bill.



Patrick
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Old 29th August 2008, 06:11 PM   #10
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You're perfectly right, Patrick. I forgot about that online shop!

Quote:
There are enough people who have built 100W AX's.
Oh dear. I think I could heat my whole flat with that.

For sure these guys have my respect.

Have fun, Hannes
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