Topic: Getting a dedicated line for gear? (Read 3211 times)

ohhgourami · « **Reply #30 on:** June 18, 2014, 07:11:18 AM »

I can probably ask my neighbor on the weekend. Actually they run that thing all weekend which could explain why this problem occurs for me a lot on Sundays.

DAC, pre, and power amp do not hum audibly from their enclosures during the phenomenon.

All my gear are separates so no headphone out and using the headphone out of the onboard sound to my preamp does not affect the buzzing/clicking during the phenomenon.

Yup, the amp buzzes/clicks in both channels with nothing connect except for mains and headphone.

My PC PSU used to buzz all the damn time, but I never heard this same buzzing through the previous baby Krell. My big Krell has been the difference in the chain that has me noticing the buzzing through the headphones.

Solderdude · « **Reply #31 on:** June 18, 2014, 07:37:56 AM »

Next question is do you have a voltmeter or can you get one ?

It would be interesting to find out if, during the humming, the mains voltage has dropped.
If this is the case it could be possible the regulators in the power supply of the Krell receive too little voltage and don't regulate.

The fact that hum goes to one side when connected seems to point in a wiring error in the Krell but could also be caused by other things.

When you never had problems with baby Krell and they only emerged after bigger brother was installed it seems to be a big brother problem.

The solution can be found when it is clear if the mains voltage has dropped too much.
There are ways to compensate using auto-trafos IF this is the case.

ohhgourami · « **Reply #32 on:** June 18, 2014, 08:48:45 AM »

I'll get a DMM this weekend. How do I test?

Solderdude · « **Reply #33 on:** June 18, 2014, 12:23:32 PM »

Set it to AC VOLTS (NEVER to AC-Amps or resistance or other setting) and if the meter has a manual range set it to AC-200V when measuring 110V for instance.

Simply put the leads in the wall socket/extension cord and note the voltage.
See if it has dropped when the AC is on or when the hum is present.

ohhgourami · « **Reply #34 on:** July 11, 2014, 05:10:26 AM »

Finally got myself a DMM to test out the voltage.

When it is buzzing, I get ~121.8V. When there is no noise it is ~120.4V.

Any ideas?

Solderdude · « **Reply #35 on:** July 11, 2014, 05:43:35 AM »

Well then it looks like it isn't a too low mains voltage that becomes so low the regulators do not work properly anymore.
If anything it looks like the higher voltage is humming.
That MAY be (hard to say) that the extra voltage could be the signal that actually becomes audible.

Do you happen to know if the hum is indeed caused by the AC of the neighbours ?

Also if you set the DMM to DC voltage and measure mains what does it say under the different circumstances ?

Another test could be to measure the AC between Line and safety ground (should be the same as mains voltage) and Neutral and safety ground.
The last one should be really low (a few volts only) under the differing conditions.

Author Topic: Getting a dedicated line for gear? (Read 3211 times)

ohhgourami

Re: Getting a dedicated line for gear?

Solderdude

Re: Getting a dedicated line for gear?

ohhgourami

Re: Getting a dedicated line for gear?

Solderdude

Re: Getting a dedicated line for gear?

ohhgourami

Re: Getting a dedicated line for gear?

Solderdude

Re: Getting a dedicated line for gear?

(adsbygoogle = window.adsbygoogle || []).push({});

Author Topic: Getting a dedicated line for gear? (Read 3211 times)