Hello.
Yesss
looking good so far now... but still Penny Dreadful through
I can adjust to zero DC approx. and it stay's very near that point. Actually the picture was taking, during trimming and the final result is preamp pendling around 0.00 --> 0.50 mV
So Salas, when i plug in the opamp, can i still adjust DC offset? or do i have to make final adjustment before plugging that in?
Anyway, i think it works! But ofcause i havent tried to actually hook it up with poweramp/speakers yet. -And without opamp yet also.
Jesper.
Yesss
looking good so far now... but still Penny Dreadful through I can adjust to zero DC approx. and it stay's very near that point. Actually the picture was taking, during trimming and the final result is preamp pendling around 0.00 --> 0.50 mV
So Salas, when i plug in the opamp, can i still adjust DC offset? or do i have to make final adjustment before plugging that in?
Anyway, i think it works! But ofcause i havent tried to actually hook it up with poweramp/speakers yet. -And without opamp yet also.
Jesper.
Attachments
Attachments
LED's :
http://www.mouser.dk/Search/ProductDetail.aspx?R=MV5064MP4Bvirtualkey63810000virtualkey638-MV5064.MP4B
On first picture, i meassure on line out (L+R).
From left to right on my pcb connection goes like this :
L_in L_out L_headphone_out R_headphone_out R_out R_in
Jesper.
Look's like rock-stable (allthrough it was pretty without)
I will hook it up to my amp. soon
Jesper.
It's ALIVE
Yes i swapped Headphone out / Line out; i think it was easier for me to do the layout this way.
Here is what i tested so far :
I have it hooked up for ~30min. with opamp inserted. DC-offset is solid, pendling very near 0.00vdc now. Bias is equal left/righ meassuring on R10 (10ohm) around 1.011vdc (101mA)... I dident check the stability of that through (did not think of that). I just took some meassurements, while it was cooking warm.
I also tried to adjust left channel dc-offset a little, after inserting the opamp. I see as you told me, it has no affect anymore.
When i have tried listning to it, everything ofcause have to be adjusted and set once more in a longer run. Also i will bolt the alubars onto a somewhat thick alu plate...
Unfortunately i have only a 10k potmeter, and an Ipad as source... But HEY
it plays music now
Jesper.
Yes i swapped Headphone out / Line out; i think it was easier for me to do the layout this way.
Here is what i tested so far :
I have it hooked up for ~30min. with opamp inserted. DC-offset is solid, pendling very near 0.00vdc now. Bias is equal left/righ meassuring on R10 (10ohm) around 1.011vdc (101mA)... I dident check the stability of that through (did not think of that). I just took some meassurements, while it was cooking warm.
I also tried to adjust left channel dc-offset a little, after inserting the opamp. I see as you told me, it has no affect anymore.
When i have tried listning to it, everything ofcause have to be adjusted and set once more in a longer run. Also i will bolt the alubars onto a somewhat thick alu plate...
Unfortunately i have only a 10k potmeter, and an Ipad as source... But HEY
it plays music now Jesper.
Attachments
I have a RaspberryPi, with an USB Dac (Also partly-DIY), but it is build in my preamp, not giving me possiblilty to take that signal right now, without taking it apart.
I am waiting for a new dac to arrive, for another Raspberry Pi! Hopefully it will be here next week..
I will let it warm up, and take a good listning anyway ofcause.
Thanks for youre interest Salas btw.
Speakers are Audiovector, 15+ years old, but very nice Danish speakers, designed by Ole Klifoth.
Poweramp is a to high gained (giving a little hum) LM4780 poweramp (My Pass B1 unitygain buffer also make the poweramp hum). So hum is not youre preamp Salas.
Jesper.
Yes and No... I have an AlephJ and an F5, but it's taking apart right now.
The torrid i am using for testing you're pre, is actually the torrid from this Pass amp.
Later this vinther i will assemble my F5 again.
I am pretty happy right now, after i have tested that it actually is working!
Jesper.
Yes... double mono it will be... The first DCSTB i did, is also called LEFT DCSTB
I also have to make an input selector for it.
The DCSTB get warm, but not more than 50C. or soo.
Jesper.