Vunce, get out first the few pico feedback cap on the second 861 please :
As well, have you some Allen Bradley 100 to 150R resistors ? 1/8 or 1/4 W ?
The reversed 861 is neutral as buffer and not necessarilly mandated according the following stage. Typically a modern pre/amp doesn't need it but the following resistor after the I/V must be tuned if you use a standalone 861 !
Edit : try CEN/SEN design in smd package : just two transistors ! the J-Fe(s)t is enjoyable but the other non Jfet doesn't need sorting out and is very neutral ! again non mandatory in a normal cable length and a modern amp/pre . But if you use headphoness.... well ! you can also use your smd 861 and a soic 8 single channel 5 V for the buff : new TI's are cool... just guessing !
As well, have you some Allen Bradley 100 to 150R resistors ? 1/8 or 1/4 W ?
The reversed 861 is neutral as buffer and not necessarilly mandated according the following stage. Typically a modern pre/amp doesn't need it but the following resistor after the I/V must be tuned if you use a standalone 861 !
Edit : try CEN/SEN design in smd package : just two transistors ! the J-Fe(s)t is enjoyable but the other non Jfet doesn't need sorting out and is very neutral ! again non mandatory in a normal cable length and a modern amp/pre . But if you use headphoness.... well ! you can also use your smd 861 and a soic 8 single channel 5 V for the buff : new TI's are cool... just guessing !
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I m testing opa810. Listened at low volumes and sounded very good.. need to test more with some known musics..
happy you like it ! ! It makes the I/V job very well but less the buffer job : exactly the opposit of the ada 4627-1 !
But the cool thing is they both are single channels oaps so an eventual layout hack is not mandatory which can be a danger -oscillations?- with some fast dual oaps adapted for single use on the pcb !
I used a pair of Traco isolated dc-dc converters to feed my board from my main 24VDC power supply. This worked well but only after I followed the manufacturer's application notes for filtering. Without the filtering I got a fair amount of audio interference.
Attachments
.....will DC be provided by Switching after Low Noise LDO is not too bad idea?
Switcher w/filtering—> LDO regulator (TPS7Axx Or LT304X type)—> DAC board
Yes, this type of psu works very well.
For AC/DC switcher the Meanwell IRM series is nice.
For DC/DC switcher Murata MEJ2 and Meanwell DCWN03
Like Paddy mentioned, output filtering is highly recommended.
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