, but what puzzled me is this :
oh, oh, oh ..........
Tomorrow I will make this.....
"In any case, to achieve this 50%, you would have to adjust R15 so that
the AC current through R1 is one half the current going through the
parallel R13 and 14. In the case of the values shown, ( generg: o,33 and two 0,47 parallel in the schematic, remind me that Aleph 3 has other values!)) that means that when the amplifier is driving a load, the AC voltage across R1 is 70% of
the voltage across the combination of R13 and 14. You can use an AC
voltmeter at 60 Hz to check this figure if you need to confirm proper
operation of the circuit. Decreasing R15 increases the percentage, and
vice versa. If you want a switchable variable/constant current source,
install a switch to break the R15 circuit."
Nelson Pass in Zen Var II
Thanks Mr. Nelson!
"In any case, to achieve this 50%, you would have to adjust R15 so that
the AC current through R1 is one half the current going through the
parallel R13 and 14. In the case of the values shown, ( generg: o,33 and two 0,47 parallel in the schematic, remind me that Aleph 3 has other values!)) that means that when the amplifier is driving a load, the AC voltage across R1 is 70% of
the voltage across the combination of R13 and 14. You can use an AC
voltmeter at 60 Hz to check this figure if you need to confirm proper
operation of the circuit. Decreasing R15 increases the percentage, and
vice versa. If you want a switchable variable/constant current source,
install a switch to break the R15 circuit."
Nelson Pass in Zen Var II
Thanks Mr. Nelson!
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let me count....14x SR100 And 4x R500....I lost one SSR100 by accident
when I am ready with my amplifier I will give the rest to friends.....
you have source resistors in both lower and upper half of circ ( meaning on your actual amp)
presuming that they're same in value - and if you have 2-channel CRO , and if you know where are both test-tips ( sonde .... proper Engrish words ?)
- just compare AC voltages across lower and upper source resistor
presuming that they're same in value - and if you have 2-channel CRO , and if you know where are both test-tips ( sonde .... proper Engrish words ?)
- just compare AC voltages across lower and upper source resistor
you mean :
seems that you will going to buy few more
especially if you are going to make susy shark
seems that you will going to buy few more
especially if you are going to make susy shark
Hi Bill, Hi Zen Mod,
the new news... yesterday I was very convinced I would measure the AC current delivered by the Semisouth and by the CCS like Nelson suggested.
this morning bevor I took out the soldering iron, I heard some music and because I had yesterday implemented three resistors for R21, the one that feeds back the signal to CCS, I switched only the three values 750 Ohm, 500 Ohm and 310 Ohm.
Result: less Ohm, louder sound, CCS contributes power
More result: sound got more and more darker, not unpleasant.
more more result: definition got worse
difficulty: changing the volume to get the same level between the steps
surprise:without any resistor (Nelson mentions this possibility) - best definition, most airy sound, nearly too soft, but impressive - a must hear
conclusions:
- because Nelson shows the decrease of distortion by using aleph ccs it must be the blend in of the IRF240, that takes away definition. I will not speak per se against the IRF, may be the mix does not work well or there is no way back the SemiSouth is simply better.
- would be interesting to replace the IRF by a Semi, I know it is not recommended, but i am interested to hear the blend with two SemiS
- small signal j-fets and SSouth are unbeatable for resolution, airiness and more or less analogue softness. (the same experience I made with ZMs Babelfish J2, being more precise, less soft)
next steps: I will try three models CCS for the differential pair, original A5 with IRF9610, two or three SK170 (see frontstage BA-2) and the solution of aleph J
and look for the sound and hum..
happy generg
the new news... yesterday I was very convinced I would measure the AC current delivered by the Semisouth and by the CCS like Nelson suggested.
this morning bevor I took out the soldering iron, I heard some music and because I had yesterday implemented three resistors for R21, the one that feeds back the signal to CCS, I switched only the three values 750 Ohm, 500 Ohm and 310 Ohm.
Result: less Ohm, louder sound, CCS contributes power
More result: sound got more and more darker, not unpleasant.
more more result: definition got worse
difficulty: changing the volume to get the same level between the steps
surprise:without any resistor (Nelson mentions this possibility) - best definition, most airy sound, nearly too soft, but impressive - a must hear
conclusions:
- because Nelson shows the decrease of distortion by using aleph ccs it must be the blend in of the IRF240, that takes away definition. I will not speak per se against the IRF, may be the mix does not work well or there is no way back the SemiSouth is simply better.
- would be interesting to replace the IRF by a Semi, I know it is not recommended, but i am interested to hear the blend with two SemiS
- small signal j-fets and SSouth are unbeatable for resolution, airiness and more or less analogue softness. (the same experience I made with ZMs Babelfish J2, being more precise, less soft)
next steps: I will try three models CCS for the differential pair, original A5 with IRF9610, two or three SK170 (see frontstage BA-2) and the solution of aleph J
and look for the sound and hum..
happy generg
I believe that small BJT will be starving at such low E-C voltage ;
anyway - be sure to set AC gain to desired level ...... because it is in function of Aleph CCS active output device
I know what's my fave , if nothing else than from engineering reasons
be aware that I'm not an engineer
o.k. I heard the aleph current source with two SemiS in the lower and upper half.I tried all three values again and the change in sound to the darker and less resolution is not remarkable. BTW this are only small changes, nothing to get grey hairs....
means, with aleph current source its better to have to similar......
and two IRF will behave well also....
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