Interesting Hum Problem - Active 2-Way

[vdi_nenna]

After your post, I saw a thread talking about this method.

I'll try it. Any specific size diode you would recommend? Maybe a diode that can handle 300v 35 amp or more, like the bridge in the power supply?

Thanks,

Vince

 

[tauro0221]

Hi,
I am using 3 amps but the recommendation is a diode that will trip the breaker.
To do a test just use any diode like the 1N400X. If it work them you decide what size to use.

 

[tauro0221]

Hi,
I am glad that it fixed the problem. I do not know who was the one that came out with this design but it worked on my amplifier. I TRIED ABOUT 20 DIFFERENT WAYS UNTIL I READ ABOUT THE TWO DIODES. I know what it is doing. I am using a diode size same as my main fuse that is 3 amps, If there are is a shorted it will blow the fuse. If you use a diode with the same size as the breaker it will be to late because your amplifier will burned.

 

[vdi_nenna]

Finally fixed the hum problem. Just want to resolve this issue.

Removed 2 of the 4 bridges and now only 2 are feeding DC to the 2 capacitor filter banks. I do not notice any degradation in sound. It actually sound better. Get more of that instant response from the drivers and a lower noise floor. This is important since this amp is driving a 93db planar driver from 600Hz to 20Khz.

😉

 

[AndrewT]

sounds like you had duplicate grounding paths using the Dual rectifier circuit.
Alternatively you put the Main Audio Ground (MAG) on the PSU charging loop and have now re-wired it to avoid this mistake.