Has anyone tried modifying the D1 I/V stage? I am wondering if it would sonically benefit if it was converted to an X type setup.
Also, what about using current sources?
Here is a picture of the stage from the service manual:
( http://www.passlabs.com/pdf/d1-srv-man.pdf )
--
Brian
Also, what about using current sources?
Here is a picture of the stage from the service manual:
( http://www.passlabs.com/pdf/d1-srv-man.pdf )
--
Brian
Attachments
conversion to 0,1mA DAC?
Hi,
I have also released a question about converting the D1 stage, maybe in the wrong forum part, because just one answers has come so far...
The essence of the tread below is: how to use the 0,1mA I-output of TDA1547 with a changed D1-stage? My idea is the reducing of bias current to ca. 1mA and use of a smaller FET like e.g. 2SK389. Is there any mistake in this realization? Thanks for feedback!
http://www.diyaudio.com/forums/showthread.php?threadid=19751
Regards
Klaus
Hi,
I have also released a question about converting the D1 stage, maybe in the wrong forum part, because just one answers has come so far...
The essence of the tread below is: how to use the 0,1mA I-output of TDA1547 with a changed D1-stage? My idea is the reducing of bias current to ca. 1mA and use of a smaller FET like e.g. 2SK389. Is there any mistake in this realization? Thanks for feedback!
http://www.diyaudio.com/forums/showthread.php?threadid=19751
Regards
Klaus
It seems that current output DACs are designed to
ideally operate into virtual grounds.
As the transconductance of the JFET in question goes
down, more signal voltage will appear at the source,
and any dependence of signal quality vs output voltage
of the DAC will start showing up.
That said, I would expect it to work fine.
ideally operate into virtual grounds.
As the transconductance of the JFET in question goes
down, more signal voltage will appear at the source,
and any dependence of signal quality vs output voltage
of the DAC will start showing up.
That said, I would expect it to work fine.
Hi Klaus,
I want to upgrade my Marantz CD 16 with the 1547 inside as well. So, I would be extremly interested to understand if you succeed in combining a 1547 with Nelson's D1-stage and basiscally what the final schematic was / how you connected it to the 1547.
Thanks & Best Regards
I want to upgrade my Marantz CD 16 with the 1547 inside as well. So, I would be extremly interested to understand if you succeed in combining a 1547 with Nelson's D1-stage and basiscally what the final schematic was / how you connected it to the 1547.
Thanks & Best Regards
Ouput Cap ?
I would like as well to ask the same question as promitheus: Why is the Output cap so large ?
Which impedance does it see ? If it sees the 22K only, than 1 uF would be sufficient. If it sees only the 150 R, 212uF would be required for 5 Hz. Sorry, that's a newbie question, but before I start to spend long time with books, I want to ask the designer pros here.
Anyway, I would prefer to understand how I could get rid of the cap anyway ?
I would like as well to ask the same question as promitheus: Why is the Output cap so large ?
Which impedance does it see ? If it sees the 22K only, than 1 uF would be sufficient. If it sees only the 150 R, 212uF would be required for 5 Hz. Sorry, that's a newbie question, but before I start to spend long time with books, I want to ask the designer pros here.
Anyway, I would prefer to understand how I could get rid of the cap anyway ?
Re: Ouput Cap ?
To get rid of the cap you would need a servo.
Blitz said:
Anyway, I would prefer to understand how I could get rid of the cap anyway ?
To get rid of the cap you would need a servo.
promitheus said:would a DC Servo circuit be bad for reproduction quality or not?
LCAudio uses two of them in there DAC I/V stage.
The only true way to judge would be to build and listen.
Re: TDA 1541 with D1 output stage
Is this a big issue?
PAM said:
How about de-emphasis filter?
Is this a big issue?
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