Quatros, M5-HPAs, and a community challenge

[ctsooner]

Fun discussion.  I'm just glad Richard knew the problem and is working on the answer.

 If you are able to do the dedicated circuit, it's probably well worth it.  I had our townhouse built with two of them in the listening room and each has a separate copper rod grounding them.   If someone tells me to make sure I separate the copper rods into the earth by more than 10 feet, I'm going to slit my wrists, hahahaha (some would actually appreciate that I think).  

I SEE a huge difference on my OLED TV when I plug it into it's own circuit or into the AQ Niagara.  I also haven't had any ground loop issues either.  I had those along with dirty electricity at a rental we had before moving here (over 18 years ago).  In doing some basic listening, I think I'm going to plug the amps AND the Quatro's directly into the wall (AQ outlet) as it seems to sound a tad better, but if casually listening, you can't really tell.  I'm now going to use the Hurricane power cords for the amp and speakers and then put Richard cords back in.  When I changed the cords, I did all the cords, a new Niagara with a Dragon cord and the new Fire interconnect.  Of course it all sounded BETTER.  Now I can take my time and really see if the cords make a difference on Richards amps.  The first round the other day didn't show a difference (I only did the Quatro's).  Design of the amps may be so good that the CAD grounding devices may not make any difference and the cord may not make a difference either.  Cords are much easier for me to make changes to or critically listen to. I have a friend coming over next week (wife gone for the week) to help me set up the Quatro's better as they are off a bit (so maybe I should wait on any cord decisions).  

On a positive note, I notice that the older I get, teh. more I want to listen to music and not play with they system. 🙂. 

[Holmz]

9 hours ago, BabySneaks said:

2) I made a recording of the hum way back when, and it seemed to peak around 120 Hz according to a frequency analyzer that is part of Audacity. But I might not know what I was doing, so I am going to attach the file. Mind you, it is not as loud as it sounds here -- I was aiming to get something that would be audible on a phone to send to a friend back when I was first wondering if the hum was "normal." Ignore the air noise at first, and you can hear the residual hum, esp. during the second half of the file.

I think that the transformer would be a 60 Hz hum, but it is easy to get frequency doubling with a non linear device. So perhaps the transformers num at 120 Hz???

The output of the rectifier circuit is certainly at 120Hz, so a part there, or a capacitor after the rectifier could be the hum source.

i don;t know if 120 Hz is a clue, but I know that 60 Hz could definitively point to the transformer.

Edited April 4, 2022 by Holmz

[BabySneaks]

Here is a complication that is a bit distressing. For about a week, I have heard an additional hum, lower in volume than that from the amp. It is there even when I turn off the M5-HPA.

I figured the neighbor's kitchen improvement involved a new fan or something. Today I went outside and did not hear anything.

With the amp unplugged, I decided on a lark to unplug the Quatro, which shares the outlet with the amp. Lo and behold, that new, additional noise went away. 

I am assuming for now the same thing that is causing the amp to hum is causing the speaker hum. I am not sure what we can do about the speaker, however.  The noise from the Quatro remained even when plugged into the HumDinger.

It is less pronounced than the amp's hum, but unlike the amp noise, this hum does seem to vary bit in volume, getting louder and quieter in 20 second cycles. 

If one more weird thing crops up, I am going to open up my house for tourists.

[Richard Vandersteen]

The sub-woofer amp does not have a transformer so the HumDinger will have no effect.  Remove the speaker wires from the QUATRO CT with the power cord still plugged in.  Does the hum go away?  Remove the power cord (at the wall) of the sub-woofer amp?  Does the hum go away?   Are both speakers doing this?  How old is the wiring in your home?  RV

[BabySneaks]

1 hour ago, Richard Vandersteen said:

The sub-woofer amp does not have a transformer so the HumDinger will have no effect.  Remove the speaker wires from the QUATRO CT with the power cord still plugged in.  Does the hum go away?  Remove the power cord (at the wall) of the sub-woofer amp?  Does the hum go away?   Are both speakers doing this?  How old is the wiring in your home?  RV

Thanks for the questions:

1) Removing the speaker wires from the speaker does not affect the hum.

2) Removing the sub-woofer amp power cord from the outlet stops the noise.

3) Only one speaker is making any noise.

4) The wiring in that room was installed before we bought the house in 2007, but the records that were left to us show electrical upgrades in the room 4 years prior. Both speakers and amps are connected to the same circuit. The main circuit panel  for the house is newer -- I had that installed seven years ago to support another project.

I have to be within three feet of the speaker to hear this noise, so it is less significant than the amp. So long as this does not damage the speaker, it is tolerable. Also, perhaps the sub-woofer amp noise is something the new dedicated circuit would solve.

As always, I appreciate your your help.

[Richard Vandersteen]

I will be interesting how any of this changes with new dedicated lines.  I know the sound will improve and a dedicated ground never hurts.  RV

[John Gallup]

Just found this discussion today and read it front to back. Don't want to sound as though I'm gloating but I must say I feel fortunate to have had M5-HPAs and Quatros for more than a year now and never had any undesirable noise since they day they were installed, with stock power cords going right to the wall outlets. (It probably doesn't hurt that the house was all wired in 2004 or so.) I don't have a "dedicated" circuit for the system as such but have moved everything else off the circuit the system uses, and soldered connections that had been made with just wire nuts. Somewhere I read that having your audio equipment on the top-most breaker in the panel is desirable, so I did that too (by switching wires) since it didn't cost anything.

It's very reassuring to see that Richard is on this case.

[Holmz]

1 hour ago, John Gallup said:

Just found this discussion today and read it front to back. Don't want to sound as though I'm gloating but I must say I feel fortunate to have had M5-HPAs and Quatros for more than a year now and never had any undesirable noise since they day they were installed

Too bad you two are not closer to each other.

 

19 hours ago, BabySneaks said:

…
I have to be within three feet of the speaker to hear this noise, so it is less significant than the amp. So long as this does not damage the speaker, it is tolerable. Also, perhaps the sub-woofer amp noise is something the new dedicated circuit would solve.
…

Is that hum at 60 or 120Hz?

 

Can you easily try a power strip off of the source and extension cords to the speakers and amps?
(I am thinking ‘ground loop’)

Edited April 5, 2022 by Holmz

[JonM]

2 hours ago, Holmz said:

Is that hum at 60 or 120Hz?

What would be the app of choice to measure?  I’m not a phone or app person. I spent a few minutes and used this app and even less time to collect these samples. Phone right next to amp.  Cats, wife, child, refrigerator all running around at time of sample  

 

[Richard Vandersteen]

You do have 60Hz but it is not the dominant noise in your room.  Don't know how this app is calibrated but it appears you have a very quiet room.  Don't know what is the source of the 85Hz  but it is unlikely the R-core transformer.  RV

[JonM]

This app is probably worth exactly what I paid for it.  Which is nothing. But.  It works better if you change the FFT setting, which I assume is Fast Fourier Transform. Which I used to actually know about in another life when I took a time series analysis class in grad school. At any rate, this one can find a peak right at 60 Hz. 
 

[BabySneaks]

5 hours ago, Holmz said:

Is that hum at 60 or 120Hz?

 

Can you easily try a power strip off of the source and extension cords to the speakers and amps?
(I am thinking ‘ground loop’)

Hi Holmz -- As for the hum hertz, maybe I can find and figure out how to use the app JonM used. I could produce charts of the speaker and the amp hums.

I do not totally grasp your second suggestion, but I can tell you what I did that might be on its path. The speaker is a bit heavy to tote about, but I did use a fat extension cord leftover from my year when I tried to use an electric lawn mower to plug it into:

• the same precise plug as the other speaker 
• a plug in an outlet connected to a different 15-amp circuit in the house, and
• a 20-amp circuit we have, for some reason, in the basement.

The speaker made the same noise no matter the outlet.

The amp is lighter, so last month I followed the same, er, circuit and got the same amp hum from all three.

With the onset of the speaker noise, depression has set in along with doubts about the competence of my management of this home improvement project. My wife is suggesting I relocate to be near that 20-amp circuit.

[Holmz]

8 hours ago, JonM said:

…  

 

 

The screen shot showing 60,180, 240 and 300 Hz make sense.
The cat purring might be the 85Hz 😉

 

5 hours ago, BabySneaks said:

….

I do not totally grasp your second suggestion, but I can tell you what I did that might be on its path. The speaker is a bit heavy to tote about, but I did use a fat extension cord leftover from my year when I tried to use an electric lawn mower to plug it into:

• the same precise plug as the other speaker 
• a plug in an outlet connected to a different 15-amp circuit in the house, and
• a 20-amp circuit we have, for some reason, in the basement.

...

I was thinking a ground loop between the signal RCAs) and the amp/speaker ground and preamp grounds being different.
So on the exact same outlet that the CD player or preamp is on… for amps and subs.

But if one just pulls the RCAs out off the preamp, does the speaker go quiet?

I recall RV mentioning just plugging the amp in without anything else… but the speaker making noise made me wonder about a ground loop,

[ctsooner]

IF it’s a ground loop, does the CAD device help?  Haven’t read up on that In ages. I’m lucky as I have dedicated circuits and never had a ground loop in this house. My older condo was brutal for some reason. 
 

really hope you can figure out what  and then hopefully correct it 

[BKDad]

If you think about it, those fancy grounding devices like CAD sells complicate the loop situation.  The hopeful idea behind their operation is that the circuit ground connections between the individual pieces of equipment and the common "ground" point are much lower impedance across the frequency range where it matters than the less obvious loop connections found in the power mains and the shields of the various interconnect cables.  That potentially (har, har 🙂) reduces the unwanted voltages between devices - Ohm's Law.  Connecting to a single common point presumably negates the voltages developed around the loop - the current goes through the path of least resistance or impedance.  

So, they might help.  Might not.  If they help - great!  They certainly add more loops to the system.  Hopefully, these lower impedance loops are physically smaller in size, too.

This is why running your entire audio system from a single outlet or from a single dedicated circuit from the breaker box is a good idea - fewer loops.  The downside of the dedicated circuit is that often that makes regular Romex cable in the wall part of of the current loops.  Those great power cables you spent so much on get defeated to a certain degree.  Better to use a single outlet *and* a dedicated circuit.  More here:

 https://jhbrandt.net/wp-content/uploads/2014/11/Hum_Buzz_and_Ground_Loops_New_Insights_Into_and_Old_Problem_AES.pdf

Even more here, from the late Pete Goudreau:

http://www.soundstagenetwork.com/articles/pete01.htm

The CAD website has a paper or three that tries to explain this in simple terms.  I personally got somewhat lost.  You kinda have to know what's going on in the background to understand the simple explanation.  But, it's worth a read.

My big point here is that the AC mains connections carry more than just 50/60 Hz AC.  Even if you had your own generator devoted entirely to your audio system, this would be true.  All the audio gear, to some degree or another, leaks currents at various frequencies that can cause problems elsewhere.  With digital gear, there's more of these currents and over a wider frequency range.

The challenges you have are that low frequency currents, like 50/60 Hz power, are handled one way.  The wavelengths are very long there and connections to a ground rod make a difference.  At lots of KHz or even MHz, where there's still possible issues in an audio system, that 30 foot wire from your stereo gear to ground varies in impedance from being close to a short circuit to being a complete open circuit.  Besides, actual ground, as in dirt, is pretty lossy once you get to the RF realm.  So, you need different approaches for higher frequencies.  Even those three foot CAD cables are a high impedance at RF.  The CAD products employ a low impedance connection for low frequencies and then apply various RF absorption material around the common connection point with an eye toward turning the higher frequency ground currents into heat.  

Truly balanced connections between the various pieces of equipment really do help with all of this.  But, they run out of effectiveness as you go higher in frequency.  Even so, there's many other good reasons why balanced circuits often work better for audio.

Some companies like Ayre and Arcam try to minimize the current loop through the AC mains ground by using a technique called "double insulation."  This meets the UL and other regulatory agency compliance rules for safety.  They don't use the ground connection in the AC power cable.  Problem reduced, at a cost.  There's lots of information on double insulation available on the interweb thingy.

It's a very complicated subject.  If you really want to delve into it, it's better to read some college physics books, like from the late Richard Feynman:

https://www.feynmanlectures.caltech.edu/II_22.html

or books from guys like the late Ralph Morrison and the late Henry Ott.  Howard Johnson - not the fried clam, ice cream, and hotel guy - is another good resource:

http://www.sigcon.com/Pubs/news/7_02.htm

[Richard Vandersteen]

54 minutes ago, BKDad said:

If you think about it, those fancy grounding devices like CAD sells complicate the loop situation.  The hopeful idea behind their operation is that the circuit ground connections between the individual pieces of equipment and the common "ground" point are much lower impedance across the frequency range where it matters than the less obvious loop connections found in the power mains and the shields of the various interconnect cables.  That potentially (har, har 🙂) reduces the unwanted voltages between devices - Ohm's Law.  Connecting to a single common point presumably negates the voltages developed around the loop - the current goes through the path of least resistance or impedance.  

So, they might help.  Might not.  If they help - great!  They certainly add more loops to the system.  Hopefully, these lower impedance loops are physically smaller in size, too.

This is why running your entire audio system from a single outlet or from a single dedicated circuit from the breaker box is a good idea - fewer loops.  The downside of the dedicated circuit is that often that makes regular Romex cable in the wall part of of the current loops.  Those great power cables you spent so much on get defeated to a certain degree.  Better to use a single outlet *and* a dedicated circuit.  More here:

 https://jhbrandt.net/wp-content/uploads/2014/11/Hum_Buzz_and_Ground_Loops_New_Insights_Into_and_Old_Problem_AES.pdf

Even more here, from the late Pete Goudreau:

http://www.soundstagenetwork.com/articles/pete01.htm

The CAD website has a paper or three that tries to explain this in simple terms.  I personally got somewhat lost.  You kinda have to know what's going on in the background to understand the simple explanation.  But, it's worth a read.

My big point here is that the AC mains connections carry more than just 50/60 Hz AC.  Even if you had your own generator devoted entirely to your audio system, this would be true.  All the audio gear, to some degree or another, leaks currents at various frequencies that can cause problems elsewhere.  With digital gear, there's more of these currents and over a wider frequency range.

The challenges you have are that low frequency currents, like 50/60 Hz power, are handled one way.  The wavelengths are very long there and connections to a ground rod make a difference.  At lots of KHz or even MHz, where there's still possible issues in an audio system, that 30 foot wire from your stereo gear to ground varies in impedance from being close to a short circuit to being a complete open circuit.  Besides, actual ground, as in dirt, is pretty lossy once you get to the RF realm.  So, you need different approaches for higher frequencies.  Even those three foot CAD cables are a high impedance at RF.  The CAD products employ a low impedance connection for low frequencies and then apply various RF absorption material around the common connection point with an eye toward turning the higher frequency ground currents into heat.  

Truly balanced connections between the various pieces of equipment really do help with all of this.  But, they run out of effectiveness as you go higher in frequency.  Even so, there's many other good reasons why balanced circuits often work better for audio.

Some companies like Ayre and Arcam try to minimize the current loop through the AC mains ground by using a technique called "double insulation."  This meets the UL and other regulatory agency compliance rules for safety.  They don't use the ground connection in the AC power cable.  Problem reduced, at a cost.  There's lots of information on double insulation available on the interweb thingy.

It's a very complicated subject.  If you really want to delve into it, it's better to read some college physics books, like from the late Richard Feynman:

https://www.feynmanlectures.caltech.edu/II_22.html

or books from guys like the late Ralph Morrison and the late Henry Ott.  Howard Johnson - not the fried clam, ice cream, and hotel guy - is another good resource:

http://www.sigcon.com/Pubs/news/7_02.htm

Romex tied down throughout the home is actually quite good!  Try making a power cord with good connectors and listen.  You will find it sound better than many after market power cords.  The challenge is to make a power cord that's flexible and sounds as good or better than the Romex in the wall.  This has been my experience.  RV

[Holmz]

The two time I thought I had a ground loop issues, it was something else.
Both were on the difficult side of things.

If the speaker or amp hums with only power and no input signal, then it is not a ground loop.

In my audio case it was a magnetic field issue, which would be rare, and should not apply to an amp or sub in a speaker.

I personally would not buy any magic device to ameliorate the issue, until we know the issue that needs to be mitigated.

Edited April 6, 2022 by Holmz

[BabySneaks]

1 hour ago, Holmz said:

If the speaker or amp hums with only power and no input signal, then it is not a ground loop.

And Holmz, this is the case for me. Both the amp and the speaker make noise when connected to nothing but power.  As I mentioned in a prior post, while disconnected from everything but power, I plugged them into other outlets on other circuits in the house. Both still make their noise.  Their partners across the room remain mute. Show offs!

As I set it up originally, the audio equipment uses plugs in the same outlet of the same circuit. Am I correct in thinking that this also precludes a ground loop?

Together, the amp and speaker sound similar to a small window air conditioner in the neighbor's house. The speaker goes through a cycle every 12 seconds of getting slightly louder then slightly softer. 

Can I assume this is not harming the speaker? Should I be cutting the power to the subwoofer amp at night?

Good news, no smoke so far!

Meanwhile, I am hammering on electrical contractors who are mostly wedded to the requirements of the code.

[Richard Vandersteen]

36 minutes ago, BabySneaks said:

And Holmz, this is the case for me. Both the amp and the speaker make noise when connected to nothing but power.  As I mentioned in a prior post, while disconnected from everything but power, I plugged them into other outlets on other circuits in the house. Both still make their noise.  Their partners across the room remain mute. Show offs!

As I set it up originally, the audio equipment uses plugs in the same outlet of the same circuit. Am I correct in thinking that this also precludes a ground loop?

Together, the amp and speaker sound similar to a small window air conditioner in the neighbor's house. The speaker goes through a cycle every 12 seconds of getting slightly louder then slightly softer. 

Can I assume this is not harming the speaker? Should I be cutting the power to the subwoofer amp at night?

Good news, no smoke so far!

Meanwhile, I am hammering on electrical contractors who are mostly wedded to the requirements of the code.

With all wires removed and only power supplied, it can't be a ground loop.  You are not asking your electrician to do anything that is not to code.  RV

[Holmz]

9 hours ago, BabySneaks said:

And Holmz, this is the case for me. Both the amp and the speaker make noise when connected to nothing but power.  As I mentioned in a prior post, while disconnected from everything but power, I plugged them into other outlets on other circuits in the house. Both still make their noise.  Their partners across the room remain mute. Show offs!

As I set it up originally, the audio equipment uses plugs in the same outlet of the same circuit. Am I correct in thinking that this also precludes a ground loop?

….

Admittedly, I was thinking a ground loop through the RCAs from the source… So that is not there with the RCAs disconnected.

If the amp and speaker are connected with a speaker cable, one could still have a ground loop… wall to amp, through speaker cables to speaker, through speaker (woofer amp) back to the wall.

Hence this:

9 hours ago, Richard Vandersteen said:

With all wires removed and only power supplied…

If one is being anal, then shorting out the inputs, or having an RCA with a 600-20k resistor on it would be dandy. But just an alligator clip (Check-n-Chong smoke older) at the end of a short RCA cable (between the shell and small male center conductor) would be great.
But I don’t think you need to do that.

 

9 hours ago, BabySneaks said:

…

Together, the amp and speaker sound similar to a small window air conditioner in the neighbor's house. The speaker goes through a cycle every 12 seconds of getting slightly louder then slightly softer. 

Can I assume this is not harming the speaker? Should I be cutting the power to the subwoofer amp at night?

…

 

That sounds like it could be “motor boating”.
I would be tempted to take the DMM and make sure it reads a 1.5V battery well, so use a low setting… then grab the alligator ends and hook the DMM to the speaker terminals… and look at DC to see if that 12 second cycle is appearing as as low DC bias.

If it is then we pretty much have an answer.

I would also suggest swapping the LHS and RHS amps,
If that speaker’s 12 second period swaps sides, then we are even more clear.

 

9 hours ago, Richard Vandersteen said:

…  You are not asking your electrician to do anything that is not to code.  RV

@BabySneaks^that^ rhetorical (question), is implicitly a sage one.

[BabySneaks]

Hello All. It has been a while, but not all has been still. Here is an update.

For those who do not recall, I am the guy who had noise from two things: buzz from one M5-HPA amplifier and what I would describe as the sound of a distant HVAC system from one Quatro speaker. That hum from the speaker was there even when not connected to the M5-HPA amp, and if I disconnected every other item from my system from a power outlet.

After several electricians flaked out, I had an electrician here a week ago to install a dedicated 20-amp line.

We have good news and no news.

Good news: The M5-HPA is largely silent now, especially when connected to the HumDinger that the Vandersteen folks had sent to me. Rather than hearing the buzz throughout the room, I now have to bend over and put my ear within a foot to hear it. For me, this noise is largely resolved.

No news: The line made no difference for the speaker "HVAC" noise. 

By chance, Mr. Vandersteen phoned me while the electrician was finishing up. In discussing the noise from the speaker, he suggested I remove the amplifier from the back of the speaker, wrap it up three times in bubble wrap, and send it to Vandersteen for a fix. I am a novice on these things, but to me, a layperson, it sounded as if there is switch that remains on that should not be doing so.

My question is this: Has anyone out there removed the amplifier from a Quatro? I will, of course, be careful and will take pictures of the wire connections so I reconnect it properly. Is the amp the entire back panel, including where the speaker wires connect and the EQ settings, etc.? Or, is it just the bottom "grill" area?

Thanks for all your help over these months.

[TomicTime]

IF it’s like a 5a or 7 then the amplifier is easy to remove. Power everything down including the Quattro unplug from wall ! remove speaker wires at Quattro. Remove screws holding the amp in. I put them in a zip lock. YES do take photos of wires 2 to the sub ! AND the terminals they connect to on the sub amp. A stack of books on floor can support the amp as you slide it out and take photos, unhook wires. A relatively small flat blade required. Hope this helps !

Glad the M5 amp issue is solved.

Vandersteen support is legendary !

 

Jim

[Richard Vandersteen]

1 hour ago, BabySneaks said:

Hello All. It has been a while, but not all has been still. Here is an update.

For those who do not recall, I am the guy who had noise from two things: buzz from one M5-HPA amplifier and what I would describe as the sound of a distant HVAC system from one Quatro speaker. That hum from the speaker was there even when not connected to the M5-HPA amp, and if I disconnected every other item from my system from a power outlet.

After several electricians flaked out, I had an electrician here a week ago to install a dedicated 20-amp line.

We have good news and no news.

Good news: The M5-HPA is largely silent now, especially when connected to the HumDinger that the Vandersteen folks had sent to me. Rather than hearing the buzz throughout the room, I now have to bend over and put my ear within a foot to hear it. For me, this noise is largely resolved.

No news: The line made no difference for the speaker "HVAC" noise. 

By chance, Mr. Vandersteen phoned me while the electrician was finishing up. In discussing the noise from the speaker, he suggested I remove the amplifier from the back of the speaker, wrap it up three times in bubble wrap, and send it to Vandersteen for a fix. I am a novice on these things, but to me, a layperson, it sounded as if there is switch that remains on that should not be doing so.

My question is this: Has anyone out there removed the amplifier from a Quatro? I will, of course, be careful and will take pictures of the wire connections so I reconnect it properly. Is the amp the entire back panel, including where the speaker wires connect and the EQ settings, etc.? Or, is it just the bottom "grill" area?

Thanks for all your help over these months.

The amp module is the part with heat sink fins but the  input panel overlaps it where the 11 pots are.  Remove the input plate first and the procedure will be obvious.  RV

[BabySneaks]

To wrap things up on this chain, we have success! After an adjustment by the Vandersteen folks, my Quatro Wood CT is now silent. It does not emit a sound like a distant HVAC when idle. 

Round trip on the panel I sent to Vandersteen took about ten days.

For anyone else in this situation, here is a guide on how to remove the panel. The panel on the exterior has the heat sink.

Unplug the power and disconnect the amplifier to the speaker. Remove 14 screws -- 7 each side (I used a 7/64th hex wrench). The top panel overlaps the bottom where the heat sink is. The bottom is what you send. Slowly guide the panel back into your hand. Take a picture of the two pairs of wires you need to disconnect. I used a No. 1 sized Phillips screwdriver and a 2.4 mm flat head screwdriver to do the wires. I removed the top wires first. Use the flathead for those. Take care you just loosen the screws as you do not want them falling out.

Thanks much to Vandersteen Audio for the guidance on getting this resolved.

[GdnrBob]

1 hour ago, BabySneaks said:

Round trip on the panel I sent to Vandersteen took about ten days.

Wow, that is service!

Perhaps we can make a sticky thread on how to disassemble components of the Vandersteen speakers/subs, etc. when they have to be shipped back to the factory?

Bob