Connection of I/V stage to TDA1541...?

[Skorpio]

I will try to replace the op-amp I/V-stage in my Philips CD960 with some of the simple discrete common base stages shown in here.

The question is, should I disconnect the resistors from the +15V line to pin 6 of the DAC?

Se here for picture:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=91833&highlight=

 

[Eric Juaneda]

Hi Skorpio,

Resistors feed DAC with 2mA. For digital zero, TDA1541 output -2mA. Theses resistors maintain NJM5534 pin 6 tension near zero volt. You can precisely adjust these resistors to obtain zero volt on pin 6, after you don't need 100uF output capacitor.

Without theses resistors, output tension on NJM5534 pin 6 will be 3.6V. It will be correct if you keep 100uF (or less) output capacitor.

Eric

 

[Skorpio]

That means, that if I use a discrete I/V stage with input adjusted to zero volts I still need the resistors?

Or I can adjust new I/V stage to -3.6V input?

 

[Eric Juaneda]

Hi Skorpio,

That means, that if I use a discrete I/V stage with input adjusted to zero volts I still need the resistors?

If I understand what you say, my response is yes.

Or I can adjust new I/V stage to -3.6V input?

??? What do you want to do? Upgrading an existing circuit or designing a new one?

Eric