tmbg
Well-known member
it measured about the same with the inputs shorted to ground.
I can post more scope pictures tonight if necessary.
I can post more scope pictures tonight if necessary.
SSL! :D
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Svart
Well-known member
no star ground for one, maybe switch to a toroid with the wires pointed away from the board? are you using a balanced input/output? when using unbalanced you want to short the non used inputs(not the outputs) to ground or else you get slightly lower gain and have to turn the makeup up higher, thus getting more noise in the output..
we can compare to one of mine if you want TMBG, just let me know when you want to. i used metal films and toroids with star grounding and have *almost* no noise. what noise their is is mostly white noise that is extremely faint.
try isolating that pcb from the chassis and running a single earth ground to the very corner of the pcb closest to the ac input. I used plastic standoffs and this cut my ground noise(ac hum) almost entirely.(turn it up max and you can still make it out in the white noise though..
we can compare to one of mine if you want TMBG, just let me know when you want to. i used metal films and toroids with star grounding and have *almost* no noise. what noise their is is mostly white noise that is extremely faint.
try isolating that pcb from the chassis and running a single earth ground to the very corner of the pcb closest to the ac input. I used plastic standoffs and this cut my ground noise(ac hum) almost entirely.(turn it up max and you can still make it out in the white noise though..
tmbg
Well-known member
I'm running all balanced - using the stereo mains from my DM24, into the SSL, into the balanced ins of my Events.
With the current EL trafo, I have the secondaries pointed at the board - that can cause hum?
Right now, I only have one electrical connection to the chassis, the earth wire of the mains input. While I was making the measurements, I had a jumper clipped between one of the input shields and chassis, at the point where the mains earth connects...
I got a toroid in the mail today, so I'll swap that in.
Svart - I'd love to compare them, when are you free? I'm available after 6 or 6:30 every day.
With the current EL trafo, I have the secondaries pointed at the board - that can cause hum?
Right now, I only have one electrical connection to the chassis, the earth wire of the mains input. While I was making the measurements, I had a jumper clipped between one of the input shields and chassis, at the point where the mains earth connects...
I got a toroid in the mail today, so I'll swap that in.
Svart - I'd love to compare them, when are you free? I'm available after 6 or 6:30 every day.
Svart
Well-known member
i've *heard* that the trafo wiring pointing at the pcb can cause hum, something about the break in shielding at the point where the wiring comes out, but I don't really know if this is accurate, it's just easy enough to move the trafo and see if it works.. :green:
mine are at the studio, I can grab one this weekend and we can meet up sometime early next week?
:guinness:
mine are at the studio, I can grab one this weekend and we can meet up sometime early next week?
:guinness:
tmbg
Well-known member
Sounds good to me!
I'm hoping this new toroid will help. The trafo I used was stolen out of an old marcad wireless receiver. It's got a shield on top, but that doesnt look all too effective
I also got my 4 pole switches, so I can have pushbutton bypass with LED!
I'm hoping this new toroid will help. The trafo I used was stolen out of an old marcad wireless receiver. It's got a shield on top, but that doesnt look all too effective
I also got my 4 pole switches, so I can have pushbutton bypass with LED!
Greg
Well-known member
yuck... connect pin 1 of the L and R input to the ground point at the chassis. See what that does.
