Amplifier hum when connected to Online UPS

[oldmonk]

No idea.. need to check.. if I connect directly to this socket bypassing the ups, there is no hum...

do check

1.5 sq mm - needs improvement IMO and IME

2.5 sq mm will be nice

4 sq mm - even better - but all this depends on your sockets & conduits also..

In Indian apartments 4 sq mm isn't possible unless we plan from the start at the time of re-modeling the house but yours seems to be an independent place so you might have more flexibility in this regard.

just to add in this post - Lapp cables are available from their bangalore depot - ordering via their website..

Finolex is good too but somehow Lapp is more "audiophile"

this might not be related to the hum - but it will be nice to trace a line backwards from your equipment to your mains to see if the mains cable is good.

 

[sud98]

I used to have a hum issue in my old house but the moment I migrated to my APC I dont see that and its completely gone.

Are you connecting directly to the UPS or the UPS is connected to a switchboard which is then connected to the amp?

 

[newlash09]

I don't think this is a case of power overload on the UPS. I was using a krell class A 100 w amp till a little while back. And I use a power regenrator that displays instantaneous wattage draw in real time.

When I first switch on the krell, the power draw goes to 420 w straight away. And then it slowly settles down to between 380 to 340w once the caps are fully charged. And it doesn't move much from there even when the music starts playing. So I guess the 1kv UPS is not struggling to feed the amp.

Second is the 5w rating, which I think can be problematic. My room had a 10A breaker, which used to trip sometimes when I switch on the krell. So I had to upgrade the same to 13A, to keep it from tripping. So possibly this could be something to be looked into.

Coming to the vertex stabilizers, I was using a 1 kv vertex cvt + 1kv vertex isolation transformer to feed the source components, and the vertex Cvt used to hum like a bee ( probably the servo stabilizers don't have this humming issue). I contacted vertex and checked the transformer mounting bolts, which were fully tight. Then I suspected EMI getting into it, and wrapped the entire insides with a copper foil. Even that didn't help, as it still kept humming away

Then I finally suspected DC on the mains, and added a power regenrator, which has actually kept things quiet. It is funny how led lights, fridge, AC, and even the telly can dump DC back into the power mains. I wish manufacturers put some dc blocker in the power inlet, as it costs nothing to implement actually. Then we would all be spared of these hum headaches.

 

[newlash09]

As an an other try, can you plug the amp into the wall socket. And then wait for 5 mins till the caps are fully charged. And then plug it immediately into the UPS and see if you still have the hum. This will remove the 5A doubt that we have

 

[Miany]

I used to have a hum issue in my old house but the moment I migrated to my APC I dont see that and its completely gone.

Are you connecting directly to the UPS or the UPS is connected to a switchboard which is then connected to the amp?

Actually I do have a power distribution block from Sound Foundations between UPS and AMP. I have tried directly connecting the AMP to the UPS. Still HUM is there!!

 

[Miany]

As an an other try, can you plug the amp into the wall socket. And then wait for 5 mins till the caps are fully charged. And then plug it immediately into the UPS and see if you still have the hum. This will remove the 5A doubt that we have

Yes.. Will try that... Meanwhile when i connect the AMP directly to the Mains, apart from the absence of HUM, there is a noticeable improvement in clarity, separation and especially DYNAMICS.

I have placed an order for Audioquest Niagara 1200 power conditioner to be used with Mains for the time being. I will revert with the feedback.

 

[Miany]

Long story short

Online UPS to Mains -> Apart from the absence of transformer hum/noise from the AMP, noticeable improvement in clarity, separation and biggest improvement in Dynamics. Having experienced this, there is no going back to UPS power in my current place. UPS is 1KVa online UPS from APC. Not sure if using a higher KVa model will make the sound better or more importantly take the transformer hum away.

Mains with Audioquest Niagara 1200 -> Now, this is a real surprise! I have never been a fan of power conditioners. Whatever i have listened to so far, i felt they always made the sound lean. Not so with this one... there is an added sense of weight and extension to base response, dynamics is really fun and most importantly, music appears to be coming from a much darker background.

I would recommend Niagara 1200 to anyone looking for a cleaner power source. I am not particularly sure about their use for power amps. My integrated amp seems to benefit heavily though.. YMMV...

 

[arj]

Good to hear ! I have found digital equipment really benefitting from power cleanup but Amps and analogue somehow losing "energy". Isolating. the Dac/CDP/Computer from the amplifier power is what gave me maximum benefit

Do try putting your Aries/Marantz on the conditioner but amp on the mains as well and listen to some dynamic tracks to see if that works.

 

[Miany]

Do try putting your Aries/Marantz on the conditioner but amp on the mains as well and listen to some dynamic tracks to see if that works.

Yes. I tried it already. But found amp on Nigara to be better.. May be the AC quality in my Mains is that bad.. not sure.. Someother place.. it might be better when directly connected to mains... but really happy with the outcome now..