Buzzing in Speaker

[Klint]

Hooping for some advice.

Having a buzz thru my Speakers.
Buzz is independent of volume and is constant.

When using my Denon 4700 and any devise it is quiet.

When adding a power amplifier i get a buzz. Tried 4 different. 3 grounded 1 un-grounded (30 year old Sansui).
Only with the Sansui it is quiet, with the others there is buzz.
Lifting ground does nothing.

Tried finding the source, going backwards, and concluded that buzz starts when powering the external amp.
So, starts when speakers have been connected and i power up the amplifier.

Any ideas?

 

[DanielT]

Hooping for some advice.

Having a buzz thru my Speakers.
Buzz is independent of volume and is constant.

When using my Denon 4700 and any devise it is quiet.

When adding a power amplifier i get a buzz. Tried 4 different. 3 grounded 1 un-grounded (30 year old Sansui).
Only with the Sansui it is quiet, with the others there is buzz.
Lifting ground does nothing.

Tried finding the source, going backwards, and concluded that buzz starts when powering the external amp.
So, starts when speakers have been connected and i power up the amplifier.

Any ideas?

Are you absolutely sure that the buzzing sound comes from the speakers not from the amplifier? Buzzing sounding transformers in older amps is common. Solution? Well, try screwing the transformer harder into the chassi. Insert rubber plates between the transformer and the chassi ... sell your amplifier. Replacing the transformer = expensive. Sorry.

Does it sound like this? :

...Although it does not have to be the fault, but somewhere we can start to start troubleshooting.

 

[Klint]

Are you absolutely sure that the buzzing sound comes from the speakers not from the amplifier? Buzzing sounding transformers in older amps is common. Solution? Well, try screwing the transformer harder into the chassi. Insert rubber plates between the transformer and the chassi ... sell your amplifier. Replacing the transformer = expensive. Sorry.

Does it sound like this? :

...Although it does not have to be the fault, but somewhere we can start to start troubleshooting.

Thanks, it sound like that, and is coming from the speakers, 100%.

 

[AnalogSteph]

When adding a power amplifier i get a buzz. Tried 4 different. 3 grounded 1 un-grounded (30 year old Sansui).
Only with the Sansui it is quiet, with the others there is buzz.

100% a ground loop. Now you know why traditional hi-fi gear is IEC Class II like the Sansui.

I presume the other ground connection will be found among the devices connected to the Denon. If you unplug everything save for one ungrounded source, the buzz should go away. Reconnect things one by one to find out what the culprit (or culprits) is. Could be network cable shield (use UTP), could be an antenna or broadband cable connection. Worst-case you'll need a line isolator.

If one of the other power amps has balanced inputs, suitably wired adapter cables could be used to tackle the issue as well.

 

[Klint]

100% a ground loop. Now you know why traditional hi-fi gear is IEC Class II like the Sansui.

I presume the other ground connection will be found among the devices connected to the Denon. If you unplug everything save for one ungrounded source, the buzz should go away. Reconnect things one by one to find out what the culprit (or culprits) is. Could be network cable shield (use UTP), could be an antenna or broadband cable connection. Worst-case you'll need a line isolator.

If one of the other power amps has balanced inputs, suitably wired adapter cables could be used to tackle the issue as well.

Thanks, the thing is that i have the buzz when the only things that are connected are, a 3-prong power amp and the speakers.
Nothing else in the system.

 

[DanielT]

100% a ground loop. Now you know why traditional hi-fi gear is IEC Class II like the Sansui.

I presume the other ground connection will be found among the devices connected to the Denon. If you unplug everything save for one ungrounded source, the buzz should go away. Reconnect things one by one to find out what the culprit (or culprits) is. Could be network cable shield (use UTP), could be an antenna or broadband cable connection. Worst-case you'll need a line isolator.

If one of the other power amps has balanced inputs, suitably wired adapter cables could be used to tackle the issue as well.

What do you think? Pull a ground cable directly into the heating element in the wall? Test different power outlets house / apartment? Are there grounded outlets?

In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them.[1] This is typically caused when enough current is flowing in the connection between the two ground points to produce a voltage drop and cause two points to be at different potentials. Current may be produced in a circular ground connection (ground loop) by electromagnetic induction.

Ground loop (electricity) - Wikipedia

en.wikipedia.org

What is it about?

 

[Klint]

Remember now, tested even more.
Tested with my 2 new Rotel RB1582mk2, grounded->BUZZ
Nuprime MCX and st10, new, grounded->BUZZ
NAD C268 grounded->BUZZ
Lifted ground on Rotel->BUZZ
Sansui ungrounded ->No BUZZ
Different power outlets, tested from Garage!
Supra dc-blocker.
95dB speakers.

Thought something in the electrical wireing, tripped everything except the pump for the floor heating and outlets in the room.

A while i was thinking, Torrodial->Magnetic field on amp cover, but why would i have current going to the speaker.

 

[Klint]

What do you think? Pull a ground cable directly into the heating element in the wall? Test different power outlets house / apartment? Are there grounded outlets?

In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them.[1] This is typically caused when enough current is flowing in the connection between the two ground points to produce a voltage drop and cause two points to be at different potentials. Current may be produced in a circular ground connection (ground loop) by electromagnetic induction.

Ground loop (electricity) - Wikipedia

en.wikipedia.org

Only device connected to outlet is the power amp.
I could have interference somewhere, but when connecting to the denon the noise is exactly the same.

 

[DanielT]

Only device connected to outlet is the power amp.
I could have interference somewhere, but when connecting to the denon the noise is exactly the same.

Out of curiosity. How close do you have to go to hear the transformer, or sound from the amplifier? If you put your ear directly to the amplifier, how does it sound then?

 

[AnalogSteph]

So what's the minimal setup that will give buzz?

What do the respective power amps do when just speakers are connected, input open? You should normally have plain ol' mechanical transformer buzz covered with the mains DC blocker.

I wouldn't rule out that it may not be a "hard" ground loop but just mains leakage... that may be enough on the Rotel for the problem to persist (though it should normally be substantially reduced), while the Sansui may have a mains transformer with shield winding to minimize capacitive coupling.

 

[Klint]

Out of curiosity. How close do you have to go to hear the transformer, or sound from the amplifier? If you put your ear directly to the amplifier, how does it sound then?

I get no BUZZ from the amp, sound comes from speakers, maybe 20cm.
When testing on a 89dB speaker almost quiet.
But with my 95dB, i can hear it.
I know, cant hear it from listening position but it is anoying, knowing it is there.
And when running from denon speaker terminals, no BUZZ at all.

 

[Klint]

So what's the minimal setup that will give buzz?

What do the respective power amps do when just speakers are connected, input open? You should normally have plain ol' mechanical transformer buzz covered with the mains DC blocker.

I wouldn't rule out that it may not be a "hard" ground loop but just mains leakage... that may be enough on the Rotel for the problem to persist (though it should normally be substantially reduced), while the Sansui may have a mains transformer with shield winding to minimize capacitive coupling.

Speaker speaker cable amplifier. Buzz.
Rca to poweramp, same buzz
Rca to denon, same.

 

[DanielT]

When did it start? How did it start? When did you discover it? Did it come gradually or just suddenly? Have you connected different hifi gadgets and after that the problems arose? Replace cables? (far-fetched but tell everything). If you want to take pictures of what you have. It can provide more insight. Something you did not think of could prove to be important. The picture of EVERYTHING, all the cables, the hifi gadgets, connections, the speakers, wall sockets and so on.

 

[Klint]

When did it start? How did it start? When did you discover it? Did it come gradually or just suddenly? Have you connected different hifi gadgets and after that the problems arose? Replace cables? (far-fetched but tell everything). If you want to take pictures of what you have. It can provide more insight. Something you did not think of could prove to be important. The picture of EVERYTHING, all the cables, the hifi gadgets, connections, the speakers, wall sockets and so on.

I noticed it with the new speakers, had Magnepan mg37i 86dB Now Dreiklang 95dB. Its barely noticable on a 90dB speaker. Otherwise nothing changed. Mcx and Rotel were quiet on the magnepans

 

[DanielT]

I noticed it with the new speakers, had Magnepan mg37i 86dB Now Dreiklang 95dB. Its barely noticable on a 90dB speaker. Otherwise nothing changed. Mcx and Rotel were quiet on the magnepans

No, now you stir the pot too much. Not different speakers. What exactly do you have now? Now that you have problems that is. Tell us what you have for hifi gadgets now? Note: A set of Source- (turntable, streamed, CD player) -Amplifier-Speakers. It is not possible to help you if you say that you connect one or the other here and there.

Nice and easy. Gradually . Now describe what you have connected.

 

[AnalogSteph]

I get no BUZZ from the amp, sound comes from speakers, maybe 20cm.
When testing on a 89dB speaker almost quiet.
But with my 95dB, i can hear it.
I know, cant hear it from listening position but it is anoying, knowing it is there.
And when running from denon speaker terminals, no BUZZ at all.

Speaker speaker cable amplifier. Buzz.
Rca to poweramp, same buzz
Rca to denon, same.

So even nothing --> power amp --> speakers? It looks like your new speakers are so efficient that they are showing up the limits of power amplifier PSRR then, especially at only 20 cm (sensitivity is approx. 94 + 14 = 108 dB SPL per 2.83 V in at this distance, so the 98 dB(A) ref. 1 W / 8 ohm SNR spec of the C268 translates to +10 dB SPL(A) worth of noise output).
What you could still try is using shorting plugs on the power amp input... if you don't have any, switch to XLR in on the C268 and short XLR pins 2 and 3 with a short pice of wire or perhaps a paperclip.

Now with speakers this sensitive, I see precious little need for an external power amplifier anyway, so I would suggest the Gordian Knot approach of just using the Denon's outputs if those work fine. Amir's measurements of this model are by no means concerning even with a 4 ohm load, and maximum output should be sufficient for peak levels of at least 115 dB SPL @ 1 m per speaker (2.0), which is more than ample.
Here's the speaker (Heco Direkt Dreiklang):

That's a wide baffle speaker indeed - the woofer is a 15"! Real Men's Loudspeakers® for sure. (The MSRP of 5000€ a piece is a bit steep, but it seems they could be had for little over 2000 lately, which is not too bad for what you get, a high-sensitivity 3-way speaker that still looks like something that belongs in living quarters. I do have to wonder what tweeter integration is like in terms of directivity, that looks like fairly little waveguide in relation to midrange size. My normal expectation would be something more akin to those found on a JBL LSR308 or Behringer B2031A.) Minimum amplifier power for 103 dB SPL out would be a modest 8 W / 4 ohms, Heco are more conservative at 20 W (107 dB SPL).

 

[DanielT]

Checked out what it's called in English, got a suggestion:
The dog slobbered on the car seat.

Replacing. I slobbered in front of the computer. The Heco speakers. Hifi porn.Excuse me I could not help it. I really like speakers with high sensitivity.Klint: Good luck solving your problems. You are in good hands now that AnalogSteph is helping you.

 

[DanielT]

I do have to wonder what tweeter integration is like in terms of directivity, that looks like fairly little waveguide in relation to midrange size.

.., that looks like fairly little waveguide in relation to midrange size. ...

Check the size of the baffle, count the distance. wave-length. They probably do not need a larger waveguide. However, speakers with a narrow baffle may need it.Rounded corners of the HECO speaker help so that the sound in the higher frequencies can slip around and not bounce on a sharp edge.

Wide and large baffle. A smart way for anyone that DIY speaker to get around the problem of baffle compensation. Here you can work a little and see what happens:

Tolvan Data

 

[Klint]

So even nothing --> power amp --> speakers? It looks like your new speakers are so efficient that they are showing up the limits of power amplifier PSRR then, especially at only 20 cm (sensitivity is approx. 94 + 14 = 108 dB SPL per 2.83 V in at this distance, so the 98 dB(A) ref. 1 W / 8 ohm SNR spec of the C268 translates to +10 dB SPL(A) worth of noise output).
What you could still try is using shorting plugs on the power amp input... if you don't have any, switch to XLR in on the C268 and short XLR pins 2 and 3 with a short pice of wire or perhaps a paperclip.

Now with speakers this sensitive, I see precious little need for an external power amplifier anyway, so I would suggest the Gordian Knot approach of just using the Denon's outputs if those work fine. Amir's measurements of this model are by no means concerning even with a 4 ohm load, and maximum output should be sufficient for peak levels of at least 115 dB SPL @ 1 m per speaker (2.0), which is more than ample.
Here's the speaker (Heco Direkt Dreiklang):

That's a wide baffle speaker indeed - the woofer is a 15"! Real Men's Loudspeakers® for sure. (The MSRP of 5000€ a piece is a bit steep, but it seems they could be had for little over 2000 lately, which is not too bad for what you get, a high-sensitivity 3-way speaker that still looks like something that belongs in living quarters. I do have to wonder what tweeter integration is like in terms of directivity, that looks like fairly little waveguide in relation to midrange size. My normal expectation would be something more akin to those found on a JBL LSR308 or Behringer B2031A.) Minimum amplifier power for 103 dB SPL out would be a modest 8 W / 4 ohms, Heco are more conservative at 20 W (107 dB SPL).

Thanks, correctly, nothing else connected.
The amplifier was bought for my older speakers and i do not need it for the current.
The Heco i bought with my mind set on efficient speaker and a low power clean amplifier. And now Topping pa5 came around.
But I don’t want to pull the trigger on a new amplifier until I understand where this noise come from. You gave me the explanation i needed and had no idea about. Is there a figure in the amp documentation one could look at?

 

[AnalogSteph]

Is there a figure in the amp documentation one could look at?

SNR / dynamic range referred to either full power or 2.83 V (1 W / 8 ohm). The latter would be 4 dB lower than Amir's 5 W dynamic range. There's only one amp in Amir's chart that clears 112 dB of 5 W SINAD, that's the Benchmark AHB2, but I'd rather assume that a Topping PA5 would be fine, too.