will the psu location inside cabinet affect sound in a negative way?
please correct a newbie before drilling more holes
any comments appreciate[emoji4] thanks
An externally hosted image should be here but it was not working when we last tested it.
please correct a newbie before drilling more holes
any comments appreciate[emoji4] thanks
You don't have much choice.
But get it working without the Chassis.
Then arrange the modules on the bench to simulate the "in Chassis" layout and measure/listen for output problems.
But get it working without the Chassis.
Then arrange the modules on the bench to simulate the "in Chassis" layout and measure/listen for output problems.
When following the above advice, have the heatsinks installed or keep in mind that power dissipation is severely limited without them.
Rundmaus
Rundmaus
thanks andrewT and rundmas
advice.
amp was working before i purchase the chassis .
i had simulate the layout and no hums or sssss can be heard.
advice.
amp was working before i purchase the chassis .
i had simulate the layout and no hums or sssss can be heard.
Do you know the rotating toroid trick?
Basically, loosen the center bold on the toroid a little bit, power on system, and while listening to audio, rotate/turn toroid transformer left and right a few degrees until you find the sweet spot where noise is the least, or disappears... power off unit, and then tighten the nut on the toroid mounting kit.
... I admit the above trick works well with mic preamps, so am not sure if they'll be as effective with power amps.
Basically, loosen the center bold on the toroid a little bit, power on system, and while listening to audio, rotate/turn toroid transformer left and right a few degrees until you find the sweet spot where noise is the least, or disappears... power off unit, and then tighten the nut on the toroid mounting kit.
... I admit the above trick works well with mic preamps, so am not sure if they'll be as effective with power amps.
With sensitive mic preamps, usually the channel nearest the AC power transformer is the more noisier one (i.e. hum pickup).
Some mic preamps also use an input or output transformer (which makes it even more susceptible) and magnetic field from the AC power toroid can influence either the input/output transformers or the XLR jacks/wires carrying the mic level audio signal.
So with the mic preamp powered on, gain on maximum setting (+66B or +72dB gain), connected to an active monitor speaker, one can hear the noise/hum/fuzz... and it's a dramatic difference when you rotate the toroid even by just a few degrees. Sometimes, even a 1-degree difference turn either left or right is enough to find the least amount of noise contribution, or even totally eliminate the noise.
As I said, I don't know if this trick works just as well with power amps, but worth the try.
Some mic preamps also use an input or output transformer (which makes it even more susceptible) and magnetic field from the AC power toroid can influence either the input/output transformers or the XLR jacks/wires carrying the mic level audio signal.
So with the mic preamp powered on, gain on maximum setting (+66B or +72dB gain), connected to an active monitor speaker, one can hear the noise/hum/fuzz... and it's a dramatic difference when you rotate the toroid even by just a few degrees. Sometimes, even a 1-degree difference turn either left or right is enough to find the least amount of noise contribution, or even totally eliminate the noise.
As I said, I don't know if this trick works just as well with power amps, but worth the try.
the field from a toroid is generally low. But that only applies where the turns are very evenly wound.
Where the windings become uneven there can be a leakage of field from the toroid. this is especially so when the Primary comes through the secondary.
There is often a "mess" of turns where the winding taps come out.
It is worth attaching longish flexible lead outs (primary and secondary/s) to make this field variation experiment possible.
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