Hi,
my Hypex quad UCD180 amp is humming.😡
This unit was build a couple of years ago but the humming only recently became an issue or more apparent when i added a minidsp 2x4HD.
But the minidsp does not seem to be at fault as the humm exists when testing the amp on the bench/kitchen table.
The amp consist of 2 smps400 power supplies each driving both an UCD180HG Hxr and an UCD180AD (with a modified opamp).
With the amps on; the test speaker (TangBand W3-871s) makes a barely audible hiss (no problem).
Once an XLR-interlink is connected to the chassis the humming starts, touching the interlink in the chassis reduces the humm.
When using my XLR to RCA interlinks, touching the male pole of the RCA amplifies the (50 Hz?) humm extremely.
see video
The weird thing is that with the mindsp connected the humming is intermittent.
It sometimes builds up and can be removed by touching/hitting/shaking the minidsp 😕
I have to add that the amp is normally not connected to an earthed socket (1980 building code). Using an earth socket makes humm less but does not remove it.
So what did I do wrong making the amp?
my Hypex quad UCD180 amp is humming.😡
This unit was build a couple of years ago but the humming only recently became an issue or more apparent when i added a minidsp 2x4HD.
But the minidsp does not seem to be at fault as the humm exists when testing the amp on the bench/kitchen table.
The amp consist of 2 smps400 power supplies each driving both an UCD180HG Hxr and an UCD180AD (with a modified opamp).
An externally hosted image should be here but it was not working when we last tested it.
With the amps on; the test speaker (TangBand W3-871s) makes a barely audible hiss (no problem).
Once an XLR-interlink is connected to the chassis the humming starts, touching the interlink in the chassis reduces the humm.
When using my XLR to RCA interlinks, touching the male pole of the RCA amplifies the (50 Hz?) humm extremely.
see video
The weird thing is that with the mindsp connected the humming is intermittent.
It sometimes builds up and can be removed by touching/hitting/shaking the minidsp 😕
I have to add that the amp is normally not connected to an earthed socket (1980 building code). Using an earth socket makes humm less but does not remove it.
So what did I do wrong making the amp?