No, Stefano, I don't!
Maybe my English is responsible, but I would like only to connect the output of the D1 without capacitors to your inputs.
In the meantime I took the documentation of the D1 and the output voltage is 14 V only with a by NP mentioned 33 V positive rail. Though, on his drawings appear only 30 V. That means, the output could already be reduced at some 12 V relativ to YOUR measured 9-10 V input bias. Right? THIS is the potential difference mentioned in my above reply, that I would like to make zero.
I think 2-3 V can already be offset by a little bit different biasing of both units. And this would mean eventually also the possibility to forget the usual preamp, connecting directly a balanced CD-player output, realised by D1, with your amp - and capacitorless.
What is your opinion?
Laci
Maybe my English is responsible, but I would like only to connect the output of the D1 without capacitors to your inputs.
In the meantime I took the documentation of the D1 and the output voltage is 14 V only with a by NP mentioned 33 V positive rail. Though, on his drawings appear only 30 V. That means, the output could already be reduced at some 12 V relativ to YOUR measured 9-10 V input bias. Right? THIS is the potential difference mentioned in my above reply, that I would like to make zero.
I think 2-3 V can already be offset by a little bit different biasing of both units. And this would mean eventually also the possibility to forget the usual preamp, connecting directly a balanced CD-player output, realised by D1, with your amp - and capacitorless.
What is your opinion?
Laci
HBarske said:
HBarske ,
Thanks ...
HBarske said:
Your correction counts infact 25 ohm would be negligible in parallel to 0.235 ohm. I made a mistake , in fact the parallel I use is 3 or 4 resistors at 2.2 ohm each (resistors can be seen in the pics)that forms respectively 0.73 (2.2//2.2//2.2) or 0.55(2.2//2.2//2.2//2.2) ohm.
Thanks
Hi Stefano!
Your circuit looks so good that I'm prepared to modify my ZV4.
I just wonder why you have 1,5 k as input resistor, because the value is higher than original ZV4 (affecting distortions at high frequencies due to input capitance of irf 240?!?)?
Also, in original ZV4 input cap was 10 mf, and in your circuit it's 100 mf?
My plan is to modify ZV4 anyway, and I'll try it with your original values this weekend... can't wait to hear it
thanks for sharing it with us!
boris
Your circuit looks so good that I'm prepared to modify my ZV4.
I just wonder why you have 1,5 k as input resistor, because the value is higher than original ZV4 (affecting distortions at high frequencies due to input capitance of irf 240?!?)?
Also, in original ZV4 input cap was 10 mf, and in your circuit it's 100 mf?
My plan is to modify ZV4 anyway, and I'll try it with your original values this weekend... can't wait to hear it
thanks for sharing it with us!
boris
Thanks Boris... 
Irfp 044 are implemented for better performance;also Zen V4 is a bit different at the output: the speaker is connected through a big capacitor and the bleeding resistor (to ground) is a 100ohm 3Watts .
In this design the speaker is connected directly to each drain ; the feedback loop takes the ac signals from a smaller capacitor and I taked care of raising the bleed resistor from 100 ohm to 330.At listening this combination doesn't seem to create problems at high frequencies and I do not feel like I need to change the 1.5k input resistors into a lower level.
That is what I find.
I had around 100uF and probably 10uF is OK too.
Irfp 044 are implemented for better performance;also Zen V4 is a bit different at the output: the speaker is connected through a big capacitor and the bleeding resistor (to ground) is a 100ohm 3Watts .
In this design the speaker is connected directly to each drain ; the feedback loop takes the ac signals from a smaller capacitor and I taked care of raising the bleed resistor from 100 ohm to 330.At listening this combination doesn't seem to create problems at high frequencies and I do not feel like I need to change the 1.5k input resistors into a lower level.
That is what I find.
I had around 100uF and probably 10uF is OK too.
Happy new year to you too Paolo .
Yes they are.
I builded and tested 2 times the amp . One time there was the active CS and the other the CCS .
Both are different from the "X" since the absence of NFB ,
and having no damping factor they present drawbakcs with conventional speakers . The Active CS played very well with JX92S drivers( I liked very much the combination) and I am interested to build a definitive version of it .
The CCS version ( currently in use )play very well on Fostex FE206E MLTL speaker. A pair of Pioneer fullrange are travelling too(BU20FU20) , and will need an enclosure design to stay in .
Yes they are.
I builded and tested 2 times the amp . One time there was the active CS and the other the CCS .
Both are different from the "X" since the absence of NFB ,
and having no damping factor they present drawbakcs with conventional speakers . The Active CS played very well with JX92S drivers( I liked very much the combination) and I am interested to build a definitive version of it .
The CCS version ( currently in use )play very well on Fostex FE206E MLTL speaker. A pair of Pioneer fullrange are travelling too(BU20FU20) , and will need an enclosure design to stay in .
stefanobilliani said:Happy new year to you too Paolo .
Yes they are.
I builded and tested 2 times the amp . One time there was the active CS and the other the CCS .
Both are different from the "X" since the absence of NFB ,
and having no damping factor they present drawbakcs with conventional speakers . The Active CS played very well with JX92S drivers( I liked very much the combination) and I am interested to build a definitive version of it .
The CCS version ( currently in use )play very well on Fostex FE206E MLTL speaker. A pair of Pioneer fullrange are travelling too(BU20FU20) , and will need an enclosure design to stay in .
Is it possible to modify the zen v4 to something similar?
I though of playing with a current amp too.
pro said:
I see you are using a 1 ohms resistor after the gain stage as the constant current source.
Would it be better if one use a constant current source instead resistor after Q1?
Have you tried to remove the aleph active current source too? NP uses CCS after and before the gain stage in First Watt, F1.
Cheers
Hock Hua
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