Tír Na HiFi

Haven't had that before. Will you keep us posted if you hear anything like that again?


Fran

Fran wrote: ↑Sun Mar 25, 2018 1:52 am Haven't had that before. Will you keep us posted if you hear anything like that again?


Fran

Oh yes!

My private message box is acting weird some are getting through some aren't,
leave message here if your trying to reach me :)

Printed a case for the Toroidals and clamped them in place over the traffos, hum was reduced a little but want to go further so going to get some potting epoxy and fill the covers with the transformers in place, will use some silicone first to seal around the wires where i have a cut out in the covers.

Open to any watch outs before i dive in over the coming days!!

Case on both clamped in position below.



Internals of case showing ribbing to allow epoxy to flow all over the traffo with cutout on the front for the wiring below.

Are the transformers on everybody's amp humming?

If it's not happening to everyone's amp could the hum be caused by a DC voltage element on the mains supply?

Sent from my SM-G930F using Tapatalk

All amps have it Simon. The case has a vented top and that doesn't help. From listening position you can't hear it. It is just when you are beside it. I put a cover over most of the top( granite chopping board) and it dampened it down. One could just ignore it but the amp sounds so good it would be nice to have it perfect. When the project started I never expected we would end up with something that finished so nicely. I know Lampizator is not state of the art finish but the group buy beats it on finish and looks.

That work looks impressive Pearse.

My Pass Labs amps are deadly quiet, absolutely nothing!
My big Teradak ATX 820W power supply has a hum that can be heard from the listening position, when is everything else quiet!
Paul Hynes 4 rails PS also dead quiet!
Two identical subs.....one quiet, one with little hum!

I'm really curious what's making this difference?!!

Set the transformers in Epoxy this evening, too lazy to disconnect them so did them in place.
Had power connected for a while during the cure tonight and it appears to have made a real good improvement damping the hum.
Still a little there but much better.
Will let them harden overnight and see how they are tomorrow.

Used the following epoxy, 2 packs did it with some left over.

damn that looks cool...

decoupling as a form of absorption should be worth trying too, from what i read its states hum is the sound of vibration, so something like rubber bushes between the mounting plate and between the tx and the head of the bolt like vibration mounts
so that the vibration gets dissipated to a large degree