555ps hums

dont use any torture in the process, and if you pick up any intelligence, please pass it on...

enjoy

ken

Although for some lucky people, the 50Hz hum is the lowest bass their system may be able to generate, albeit it not through the speakers. Bassheads like Arun may actually like it!

My old 300 used to hum - if my other half was using her hairdryer, bad mains etc. My Supercap was silent apart from a slight hum with an ear pressed up against the case. Every Sunday morning, at the same time each week, it would 'croak' every couple of seconds for about 15 minutes - a sound i've not heard a transformer do  before. It stopped doing this for two weeks when we had problems with the sewage pumps at the bottom of our cul de sac and needed a tanker to take away the effluent each day whilst they repaired the wet well pumps. Noticing the coincidence I asked one of the engineers what operation was going on every Sunday morning and he explained that the wet well pumps were running an anti ragging cycle where they run back and forth to break up any rags that may have bound onto the impellers. This wasn't working correctly hence the work. Once they were done and the pumps had been replaced, along with a new control system, my 300 never croaked again...

James

Ken, yes it most likely is to do with the tension in the laminates.

Tony if like me in Suffolk you at long lengths of 11kv overhead and then over head 240 v local distribution from a 'substation'  on top of a wooden pole  you will probably find your voltage variation and DC in the mains is less than ideal. (though in the last couple of years it has improved)

Simon

I reduced the hum in a HC and 250 by having the transformer mounting tightened.

Wouldn't it be better if the transformers were mounted on some kind of floating suspension?

They would be better if they were encapsulated and potted, but that easily doubles the price of the already very expensive transformers. 

my system has 10 boxes only the naim is nds5 /ndac/5xp psu .Cannot hear any hum coming from other units other than nds5 streamer which is not loud but can be heard 

So, does mine too. My 555ps, 552ps and 500ps.

I think big size transformer hum noise is more BIG. My tuner PSU didn't hear hum noise.

I solved my Naim PSU hum noise with PS Audio Humbuster III.

What is this model? What is the power rating? Is it humming?