PCB´s are not very good when you need to remove parts and resolder them again.
The link between R5 and +28v was lifted when I removed the initial resistors. (In both channels
)
Now I made a shunt and left it burning during the night.
Voltages are similar in both channels and the sound is quite good.
I used Kiwames all around and that got rid of the edgyness.
I hear a background hum that is reduced by linking the case to the star GND... Should I connect this star GND to the Mains GND also ?
Ricardo
The link between R5 and +28v was lifted when I removed the initial resistors. (In both channels
)Now I made a shunt and left it burning during the night.
Voltages are similar in both channels and the sound is quite good.
I used Kiwames all around and that got rid of the edgyness.
I hear a background hum that is reduced by linking the case to the star GND... Should I connect this star GND to the Mains GND also ?
Ricardo
Connect metal case to mains GND near the IEC socket. Use short link from star GND to case also. Keep mains transformer and AC IEC socket or just AC cable to the far opposite side of RCAs and phono board. 20cm and over is best. Happy for you that the issue was something easily traceable in the end. Show us some pictures of the migrated construction if you have. I might spot something for GND etc that can be done better.
Thank you Gentlemen.
I will correct this and report "damages" latter.
I just ordered some Obbligato 4.7u from Peter and need some shinkoh for the Rload.
I tryed parts collection but I seem to be having trouble with their sales Team.... Maybe I will try hifi collective for the shinkohs.
If it proves very difficult, can I use Kiwames for Rload ?
Regards
Ricardo
I will correct this and report "damages" latter.
I just ordered some Obbligato 4.7u from Peter and need some shinkoh for the Rload.
I tryed parts collection but I seem to be having trouble with their sales Team.... Maybe I will try hifi collective for the shinkohs.
If it proves very difficult, can I use Kiwames for Rload ?
Regards
Ricardo
Hi nicoch46
My system needs some more "air" so I believe I will try a higher value if I use kiwame.
johnm, how do the Takman compare with shinkoh ?
Ricardo
PS, I will not connect the pcb GND plane because I have 119 mV offset there....
Can not imagine why... it should not be connected with anything... maybe a micro short circuit ???
Also, can I connect all RCA GND to a central star GND ? (My pcb has only one point for GND per channel and the GND plane is (should) not be in contact with the others).
Please note that the coax I use in the inputs, only connects the GND on the RCA (not in the pcb)... the GND from each channel is connected to the star GND... that is why I do not have gnd loops.
Ricardo
My system needs some more "air" so I believe I will try a higher value if I use kiwame.
johnm, how do the Takman compare with shinkoh ?
Ricardo
PS, I will not connect the pcb GND plane because I have 119 mV offset there....
Can not imagine why... it should not be connected with anything... maybe a micro short circuit ??? Also, can I connect all RCA GND to a central star GND ? (My pcb has only one point for GND per channel and the GND plane is (should) not be in contact with the others).
Please note that the coax I use in the inputs, only connects the GND on the RCA (not in the pcb)... the GND from each channel is connected to the star GND... that is why I do not have gnd loops.
Ricardo
Attachments
So you use your input shields one way. Hmmm... Better use a single wire from each RCA ground to the star then, plus one wire from the ground plane center to the star. Earth star to nearest point on chassis. You got some mV on GP because it is floating most probably. Do those things and see if your sound got deeper and your hum lesser.
salas said:Wacko reg! I like.
Sure, I will try it. For the high freq noise I tried an LC filter right in front of the 3.3R resistor (L=150uH, C=2900u) and you wouldn't believe the psrr curve. But I'm willing to try the CCS mosfet, I just don't understand what it looks like, sorry
(and where it goes).