Neumann KH420 Review (Studio Monitor)

[Vintage57]

FWIW
I never turn mine off.
The KH 420’s have been on for over 5 years.
My ATC’s in my HT have been on for 20 years
Keeping all circuits from being shut down prolonging the life of the components

 

[Shadow Dancer]

Wow
that is good information thank you.
This is the sound I'm referring to.

 

[MikeP]

Hi
Past week I acquired a pair of 420 , I love them.
But I have noticed that on one unit when you turn it on it makes a mini pop sound.
is this normal?
On the other unit it doesn't sound as loud but it does.
The sound is fantastic on both units, but I'm afraid this will damage the speaker.

I turn on the speakers with all the volumes at zero, I have also changed plugs and power wiring, the same speaker always does it.

If you're located in Europe and using schuko plugs, try reversing the plugs in their socket (swapping phase and neutral connections). In my case, it helped. Initially, I had a small pop every time I turned on the units. Then, after doing the final cabling, observing the correct phase connection at the IEC input plug, it went away. Now, they are completely silent at power on. Hope it helps.

 

[Jaxjax]

This is the sound I'm referring to

That sounds as if a preamp relay is going off then power up pop. Is your preamp already on .? 420 turned on last ? I would just leave it on . Do they still do it when coming out of sleep mode when signal is applied?

 

[DJBonoBobo]

FWIW
I never turn mine off.
The KH 420’s have been on for over 5 years.
My ATC’s in my HT have been on for 20 years
Keeping all circuits from being shut down prolonging the life of the components

Wow, you are burning 120W idle power 24/7 for 5 years just because of a hypothetical longer component life?
This means around 5,000 kwh - in my country between 1,500 and 2,500 EUR.

 

[Shadow Dancer]

If you're located in Europe and using schuko plugs, try reversing the plugs in their socket (swapping phase and neutral connections). In my case, it helped. Initially, I had a small pop every time I turned on the units. Then, after doing the final cabling, observing the correct phase connection at the IEC input plug, it went away. Now, they are completely silent at power on. Hope it helps.

thank you so much!
I'll try it this afternoon

 

[Shadow Dancer]

That sounds as if a preamp relay is going off then power up pop. Is your preamp already on .? 420 turned on last ? I would just leave it on . Do they still do it when coming out of sleep mode when signal is applied?

No
the speaker is off and only does so when I turn it on.

 

[Vintage57]

Wow, you are burning 120W idle power 24/7 for 5 years just because of a hypothetical longer component life?
This means around 5,000 kwh - in my country between 1,500 and 2,500 EUR.

It’s only about €400 for me. Or less than €7 per month.

What is your point?

 

[DJBonoBobo]

It’s only about €400 for me. Or less than €7 per month.

What is your point?

My point is that if you don't live in a country with clean and cheap energy - like Canada or Norway -, it is not a good idea leaving devices with 60W idle power consumption per piece on 24/7 if you are not using them.

 

[paudio]

It’s only about €400 for me. Or less than €7 per month.

What is your point?

What components life is it lengthening? Hours at temperature takes a toll on things.

 

[Jaxjax]

What components life is it lengthening? Hours at temperature takes a toll on things.

I would think relays would be the biggest issue. I don't know if ATC does a standby/ sleep mode but thought it was EU law on such components. Mine coming out of sleep mode definitely fires off a relay.

 

[paudio]

I would think relays would be the biggest issue. I don't know if ATC does a standby/ sleep mode but thought it was EU law on such components. Mine coming out of sleep mode definitely fires off a relay.

Lots of failures I find are actually in the standby circuit itself because it remains powered all the time. If it doesn't have standby then I find failures in the hottest area or with the lowest quality/lowest rated capacitors.

If you are using it 12 hours a day you could keep it on 365 days a year and only have 4350 hours of extra of 8760 total on time but you would have avoided 365 on and offs or heat cycles.

If you are using it 8 hours a day and you turn it on and then off each time you'd only rack up up 2920 hours a year. You would have had 365 on and offs or heat cycles though.

It all depends what is going to fail first in the design. Anecdotally I mostly have issues with power supply/standby sections of devices, including active speakers and other professional audio equipment found in studios. Within that it is mostly due capacitors deteriorating. Once those get out spec sometimes the device fails to operate without damage. Other times the added stress in the circuit will cause the power IC, mosfet and other components in the circuit to blow out.

My O410 have some sort of power saving mode in them. I turn them off though as I use them a few times a week.

 

[Jaxjax]

My O410 have some sort of power saving mode in them. I turn them off though as I use them a few times a week.

I basically do the same. I switch a power strip off for anything other then my days off which I tend to leave on in standby.

 

[dfuller]

I also leave mine on all the time. They aren't biased very far into Class A, they idle at pretty reasonable temperatures without much power draw.