Question Hegel H390 - does it hum?

[KnobblySausage]

Hi.

I’m currently auditioning a Hegel H390 amp. While I’m impressed with the sound quality, I have a concern that there is quite a noticeable electrical ‘hum’ coming from the chassis of the device. It is clearly audible from at least 3 metres away while there is nothing playing, across all inputs. As I say, it comes from the chassis, not through the speakers.

It only happens when the device is powered on. It is silent in standby.

Changing the amp’s position, power cable and audio connections makes no difference.

I am interested to hear from other owners of these amps whether This is normal, or whether I could have a faulty test device.

Thanks in advance.

Rory

 

[Al ears]

Probably a faulty device. No reference to any hum in any of the reviews I have read.
Don't actually own one unfortunately.
Can you get a replacement to audition?

 

[Gray]

Hi.

I’m currently auditioning a Hegel H390 amp. While I’m impressed with the sound quality, I have a concern that there is quite a noticeable electrical ‘hum’ coming from the chassis of the device. It is clearly audible from at least 3 metres away while there is nothing playing, across all inputs. As I say, it comes from the chassis, not through the speakers.

It only happens when the device is powered on. It is silent in standby.

Changing the amp’s position, power cable and audio connections makes no difference.

I am interested to hear from other owners of these amps whether This is normal, or whether I could have a faulty test device.

Thanks in advance.

Rory

I believe they use a separate transformer for standby, seems like the main one in yours is the cause.
I'd doubt it was a common problem. (Would hope not).
Out of interest, you are not using the distributer's (£250 + VAT) home loan service are you?

 

[Deleted member 188516]

Hi.

I’m currently auditioning a Hegel H390 amp. While I’m impressed with the sound quality, I have a concern that there is quite a noticeable electrical ‘hum’ coming from the chassis of the device. It is clearly audible from at least 3 metres away while there is nothing playing, across all inputs. As I say, it comes from the chassis, not through the speakers.

It only happens when the device is powered on. It is silent in standby.

Changing the amp’s position, power cable and audio connections makes no difference.

I am interested to hear from other owners of these amps whether This is normal, or whether I could have a faulty test device.

Thanks in advance.

Rory

try lifting the unit off its rubber feet and using a hard cone / material underneath instead.

this should help drain out any vibration created by the unit itself.
(a little tip from russ andrews dare i say !).

this may (or may not) stop this vibration as the rubber feet supplied will trap any vibrations inside the unit.

i did this under my sony 930 amp years ago and it stopped the annoying transformer hum - made no sound quality difference though !

 

[MUSICRAFT]

Hi.

I’m currently auditioning a Hegel H390 amp. While I’m impressed with the sound quality, I have a concern that there is quite a noticeable electrical ‘hum’ coming from the chassis of the device. It is clearly audible from at least 3 metres away while there is nothing playing, across all inputs. As I say, it comes from the chassis, not through the speakers.

It only happens when the device is powered on. It is silent in standby.

Changing the amp’s position, power cable and audio connections makes no difference.

I am interested to hear from other owners of these amps whether This is normal, or whether I could have a faulty test device.

Thanks in advance.

Rory

Some of our clients also experienced similar problems with their H360's. What has the dealer said please?

 

[KnobblySausage]

Probably a faulty device. No reference to any hum in any of the reviews I have read.
Don't actually own one unfortunately.
Can you get a replacement to audition?

Thanks for your reply. I’ve not seen it mentioned in reviews either. So was interested in some real life experience. Sadly the dealer I use just has the one on loan, I’ll see what they have to say over the coming days. Cheers.

 

[KnobblySausage]

I believe they use a separate transformer for standby, seems like the main one in yours is the cause.
I'd doubt it was a common problem. (Would hope not).
Out of interest, you are not using the distributer's (£250 + VAT) home loan service are you?

It does sound like a transformer hum. And it seems to intensify and then subside, especially after it’s warmed up with some music played fairly loud. I’d hope it wasn’t a common problem.
No, not using the £250 home loan service. I’m using to my local dealer who has a decent reputation. Cheers.

 

[daytona600]

Could be 50hz main hum or DC leakage on the mains
BMU balanced mains / isolation transformer should cure this
quality mains is important for best sound

 

[KnobblySausage]

try lifting the unit off its rubber feet and using a hard cone / material underneath instead.

this should help drain out any vibration created by the unit itself.
(a little tip from russ andrews dare i say !).

this may (or may not) stop this vibration as the rubber feet supplied will trap any vibrations inside the unit.

i did this under my sony 930 amp years ago and it stopped the annoying transformer hum - made no sound quality difference though !

Interesting idea, I’ll look into giving that a go.Hopefully the rubber feet can be easily refitted as this is a demo unit. Thank you.

 

[KnobblySausage]

Could be 50hz main hum or DC leakage on the mains
BMU balanced mains / isolation transformer should cure this
quality mains is important for best sound

Have just heard back from Hegel support who have said something similar. So will try doing that. Thanks for your response.

 

[KnobblySausage]

Some of our clients also experienced similar problems with their H360's. What has the dealer said please?

That doesn’t sound so good. It’s a shame as I am enjoying the sound it has. Hegel have said it could be due to the mains having DC leakage and to try and isolate any noise on the supply.Cheers.

 

[newlash09]

I would second the DC leakage into the mains AC too. There are DC blockers for just these scenarios. However before you invest in one. Maybe a Better idea to try out the amp at the dealers, and see if the physical hum returns there.

If you are willing to spend more than a DC blocker, then a balanced power transformer will be the next step up. For even more money , you can also get a power regenarator. But these are seriously expensive. But make audible improvements. I had very serious power problems. Which also fried an amp once. So I went for a power regenrators, and I felt I only had improvements all around. YMMV

 

[Deleted member 188516]

Could be 50hz main hum or DC leakage on the mains
BMU balanced mains / isolation transformer should cure this
quality mains is important for best sound

if a balanced mains unit is what your after try these people as they are not the usual hifi rip off prices...

Toroidal Transformer Range | Airlink Transformers

UK Manufacturer of toroidal transformer products including voltage converters, custom built transformers and balance power supplies. View the range and buy now

airlinktransformers.com

 

[Gray]

It's a problem that some Audiolab 6000A owners have reported.
DC in with their mains has pushed otherwise quiet mains transformers into becoming buzzers.

 

[Deleted member 188516]

It's a problem that some Audiolab 6000A owners have reported.
DC in with their mains has pushed otherwise quiet mains transformers into becoming buzzers.

how much would it cost for a manufacturer to include these dc blockers in their amplifier designs ?

one good thing about the mf m6i i had is that it was silent as regards to transformer hum.

 

[Electro]

I can recommend these DC blockers from ATL Audio , the are extremely good value at £78 each .
I have two of them and they work extremely well and the build quality is excellent .
I have several pieces of equipment that have huge toroids that are prone to hum if there is DCon the mains and they are now all extremely quiet .
One thing I did not expect was the increase in overall sound quality when using them in my system.
https://www.atlhifi.com/shop/fully-...r-trap-filter-assembled-in-case/?currency=GBP

 

[Gray]

[QUOTE="plus 1, post: 1206234, member: 188516"
one good thing about the mf m6i i had is that it was silent as regards to transformer hum.
[/QUOTE]
Yes. This Hegel amp is the best part of 5 grand. Call me old fashioned but for half of that price, I'd be expecting perfection.
Of course Hegel / Audiolab could say it's not their fault there's DC on the mains.
To which I'd ask how other amps can be silent when powered by the same mains supply.

 

[MUSICRAFT]

Have just heard back from Hegel support who have said something similar. So will try doing that. Thanks for your response.

My response to Hegel was simple. Please replace the amps.

 

[MUSICRAFT]

That doesn’t sound so good. It’s a shame as I am enjoying the sound it has. Hegel have said it could be due to the mains having DC leakage and to try and isolate any noise on the supply.Cheers.

Thanks for your reply

I was told that this issue would not be present in future products.

Anyway, another amplifier to also consider at the £5k mark is Lyngdorf Audio's TDAI-3400. The TDAI-3400 doesn't need any line conditioning or external power filtering and you won't hear any noise from the amp itself or any noise from partnering loudspeakers. Just all round silence.

Btw, and fwiw i am using a TDAI-3400 and i can tell you that once its effectively configured it's one very serious product.

 

[Deleted member 188516]

Thanks for your reply

I was told that this issue would not be present in future products.

Anyway, another amplifier to also consider at the £5k mark is Lyngdorf Audio's TDAI-3400. The TDAI-3400 doesn't need any line conditioning or external power filtering and you won't hear any noise from the amp itself or any noise from partnering loudspeakers. Just all round silence.

Btw, and fwiw i am using a TDAI-3400 and i can tell you that once its effectively configured it's one very serious product.

better than a set of atc actives ?

 

[daytona600]

Have just heard back from Hegel support who have said something similar. So will try doing that. Thanks for your response.

£5,000 amp should work on any AC power grid if correctly designed
fully regulated / linear power supply will not hum , but they cost more
Used to have a massive musical fidelity amp with a giant PSU & you could switch it off & it would still play music for a few minutes
amps are amps & volts are volts all over the globe

 

[MUSICRAFT]

better than a set of atc actives ?

Well RoomPerfect room correction is compatible with passive and active and loudspeakers. RoomPerfect will help the loudspeakers perform at their optimum in your own room and that's what really matters.

 

[Deleted member 188516]

Well RoomPerfect room correction is compatible with passive and active and loudspeakers. RoomPerfect will help the loudspeakers perform at their optimum in your own room and that's what really matters.

thanks for the reply - was not aware of the "room perfect" product.

so any advantage that actives (may) have as regards to the on board amplifiers being perfectly tuned / matched to the loudspeaker drive units has been eliminated ?

 

[Surly Sid]

Not only should a Hegel amp not hum; according to mags like Hifi+, they walk on water, turn water into wine and lay golden eggs for you.

In my opinion, Hegel = Overrated

 

[MUSICRAFT]

thanks for the reply - was not aware of the "room perfect" product.

so any advantage that actives (may) have as regards to the on board amplifiers being perfectly tuned / matched to the loudspeaker drive units has been eliminated ?

You’re welcome.

RoomPerfect is a feature of the TDAI-3400 is Lyngdorf Audio’s proprietary digital room correction technology which maps and corrects for the acoustical errors of your room.

Regardless of the theoretical advantage active speakers have over passive however both types will ultimately be placed in a room. RoomPerfect will correct the acoustical errors of your room and helps your loudspeakers perform at their optimum and that's what really matters.