Denon X3800H / Classe Audio CA-5200 - Ground Loop through RCA-cables?

[ban25]

So you have a ground loop between amp and AVR, this is not uncommon. The solution is to tie the chassis ground together using a ground wire, e.g. from ground terminals provided on both pieces of equipment. On the AVR, that would be the phono ground lug. Unfortunately, looking at the back of the CA-5200, I do not see an obvious ground lug. The traditional way to resolve ground loops is to use balanced interconnects. The CA-5200 has them, but unfortunately, the X3800H does not. So, I think there are two options:

1. Ditch the idea of using the CA-5200 -- the internal X3800H amps are fine anyway
2. Ditch the X3800H and replace it with something with balanced interconnects

Option 1 is of course the most cost-effective approach

 

[Hobolicious]

So you have a ground loop between amp and AVR, this is not uncommon. The solution is to tie the chassis ground together using a ground wire, e.g. from ground terminals provided on both pieces of equipment. On the AVR, that would be the phono ground lug. Unfortunately, looking at the back of the CA-5200, I do not see an obvious ground lug. The traditional way to resolve ground loops is to use balanced interconnects. The CA-5200 has them, but unfortunately, the X3800H does not. So, I think there are two options:

1. Ditch the idea of using the CA-5200 -- the internal X3800H amps are fine anyway
2. Ditch the X3800H and replace it with something with balanced interconnects

Option 1 is of course the most cost-effective approach

Hmm, I really hope it does not come to the need of ditching either of the units. If ditching the Classe I would still be in need of a new power amplifier as the Denon X3800H is not able to run all my speakers on its own.

 

[ban25]

Hmm, I really hope it does not come to the need of ditching either of the units. If ditching the Classe I would still be in need of a new power amplifier as the Denon X3800H is not able to run all my speakers on its own.

There is a third option: Live with the hum. You could try switching from speaker wire to a ground wire with spade connectors like the ones offered by BJC:

Stereo Cables at Blue Jeans Cable

This may provide a more secure connection that will further reduce the level of ground hum, potentially to an acceptable level. Another thing to try, since there is no dedicated lug, is to move the point where the ground wire is connected on the amp. You could even try one of those bolt-on ground lugs:

XB-MGLU

Bolt-On Master Ground LugThe importance of a solid ground connection is paramount in any 12 V installation. Our Master Ground Lug accepts multiple ground wires (with a power ring on each), and bolts securely to the vehicle's sheet metal, creating a large and secure electrical contact for reduced...

www.jlaudio.com

No idea how well it works.

If you have to replace the amp, you just need something that can drive 2-channels and has a proper ground lug.

If you decide to replace the AVR, get something with XLR outputs, something like the Denon A1H, Yamaha A6A, Integra DRX-8.4, Pioneer 805, or even a dedicated processor like the AV10, AVM70, or HTP-1. If you went for the Denon, Integra, or Pioneer, there would be no need for additional amplification anyway since those units all have at least 11-channels of amplification. With the processors, you will of course need external amplification for all channels.

FWIW, I've had ground loops with every amplifier I've ever owned (except subwoofers, for whatever reason!), and it's always been solved by either XLR interconnects or dedicated ground wires.

 

[PENG]

So you have a ground loop between amp and AVR, this is not uncommon. The solution is to tie the chassis ground together using a ground wire, e.g. from ground terminals provided on both pieces of equipment. On the AVR, that would be the phono ground lug. Unfortunately, looking at the back of the CA-5200, I do not see an obvious ground lug. The traditional way to resolve ground loops is to use balanced interconnects. The CA-5200 has them, but unfortunately, the X3800H does not. So, I think there are two options:

1. Ditch the idea of using the CA-5200 -- the internal X3800H amps are fine anyway
2. Ditch the X3800H and replace it with something with balanced interconnects

Option 1 is of course the most cost-effective approach

Tie the chassis together is more of a myth that might work in some specific cases only.

Isolation will work for sure.

 

[Hobolicious]

There is a third option: Live with the hum. You could try switching from speaker wire to a ground wire with spade connectors like the ones offered by BJC:

Stereo Cables at Blue Jeans Cable

This may provide a more secure connection that will further reduce the level of ground hum, potentially to an acceptable level. Another thing to try, since there is no dedicated lug, is to move the point where the ground wire is connected on the amp. You could even try one of those bolt-on ground lugs:

XB-MGLU

Bolt-On Master Ground LugThe importance of a solid ground connection is paramount in any 12 V installation. Our Master Ground Lug accepts multiple ground wires (with a power ring on each), and bolts securely to the vehicle's sheet metal, creating a large and secure electrical contact for reduced...

www.jlaudio.com

No idea how well it works.

If you have to replace the amp, you just need something that can drive 2-channels and has a proper ground lug.

If you decide to replace the AVR, get something with XLR outputs, something like the Denon A1H, Yamaha A6A, Integra DRX-8.4, Pioneer 805, or even a dedicated processor like the AV10, AVM70, or HTP-1. If you went for the Denon, Integra, or Pioneer, there would be no need for additional amplification anyway since those units all have at least 11-channels of amplification. With the processors, you will of course need external amplification for all channels.

FWIW, I've had ground loops with every amplifier I've ever owned (except subwoofers, for whatever reason!), and it's always been solved by either XLR interconnects or dedicated ground wires.

Thanks for the follow-up. How I have currently connected the speaker wire is through the use of ring terminals that are then mounted behind screws on each of the units.

As for replacing the units, I currently can't justify the step up to for example the Denon A1H, but I guess there could be a case for going to the Denon X6800H when it is available (selling both the Denon X3800H and Classe Audio CA-5200).

I guess two somewhat cheap tests before going to such a step is to at least try some RCA Ground Loop Isolators on the three RCA cables running between the receiver and power amplifier, and/or testing out the RCA to XLR cables instead of the current RCA to RCA cables.

 

[Hobolicious]

Tie thr chassis today is more of a myth that might work in some specific cases only.

Isolation will work for sure.

What do you mean by "Isolation" in this case, PENG?

 

[PENG]

From what I can hear the sound quality seems fine (except for the obvious issue with the troublesome noise).

In regard to the Monoprice they don't seem to be available locally (mainly seem to be available in the US?). I did find the Benchmark cables in a store, but it is obviously a hefty price for cables. They are about 80 USD per 6ft cable. I am also a bit uncertain if 6ft is just a tad short (7ft would probably be better as a minimum), but might be just enough.

Do you know if there are any decent brands typically available in Europe (either Norway or UK, as I am heading over there in a months time)? I assume RCA Female to XML Male adapters are a no-go (and would not replace my current RCA cables if you believe they might be causing the issue)?

From a very quick search locally I find for example (outside of insanely expensive cables):
- Cordial CFU 3 MC
- Roland RCC-10-RCXM
- Adam Hall K3TM
- There also seem to be some Klotz RCA to XLR (Supreme/Superior or AT-CM0300) cables available

Yes, there are the March Audio one that may be expensive, and a liw cost one by Ghent Audio, that may have to be shipped from HK.

 

[PENG]

What do you mean by "Isolation" in this case, PENG?

Isolation transformer, or signal isolator, google it or I'll do it later when I get a chance.

 

[ban25]

Tie thr chassis today is more of a myth that might work in some specific cases only.

Isolation will work for sure.

So long as it's not done with a cheater plug

Ground Loops - Eliminating System Hum and Buzz

Got an annoying hum or buzz in your audio system? You likely have a ground loop. This article helps you diagnose the problem so it can be eliminated. Don't put up with hum. Read this article!

www.audioholics.com

 

[ban25]

Thanks for the follow-up. How I have currently connected the speaker wire is through the use of ring terminals that are then mounted behind screws on each of the units.

As for replacing the units, I currently can't justify the step up to for example the Denon A1H, but I guess there could be a case for going to the Denon X6800H when it is available (selling both the Denon X3800H and Classe Audio CA-5200).

I guess two somewhat cheap tests before going to such a step is to at least try some RCA Ground Loop Isolators on the three RCA cables running between the receiver and power amplifier, and/or testing out the RCA to XLR cables instead of the current RCA to RCA cables.

The 6800 will not help you. You need XLR pre-outs specifically. I think the cheapest options that will fit the bill are the Yamaha A6A/A8A or Pioneer 805. RCA ground loop isolators might work -- never tried them. RCA to XLR cables will do nothing.

 

[Hobolicious]

Isolation transformer, or signal isolator, google it or I'll do it later when I get a chance.

Like the Jensen Iso-Max CI-1RR? That was at least something I stumbled across when trying to look up signal ground isolators, but it seemed very expensive (considering I would need a few of them).

I know there are quite cheap RCA Ground Loop Isolators that are probably frowned upon, but I am not sure if it might be worth a shot considering they are like 10-15 USD or so a piece?

 

[Hobolicious]

The 6800 will not help you. You need XLR pre-outs specifically. I think the cheapest options that will fit the bill are the Yamaha A6A/A8A or Pioneer 805. RCA ground loop isolators might work -- never tried them. RCA to XLR cables will do nothing.

I believe the Denon X6800H can run 11 speakers without external amplification, so it would run my 7.2.4 setup on its own (hence the "selling both the Denon X3800H and Classe Audio CA-5200").

 

[ban25]

I believe the Denon X6800H can run 11 speakers without external amplification, so it would run my 7.2.4 setup on its own (hence the "selling both the Denon X3800H and Classe Audio CA-5200").

Oh yes, that's right. . Anything with 11-channels+ built in will sort you out just fine.

 

[TLS Guy]

I believe the Denon X6800H can run 11 speakers without external amplification, so it would run my 7.2.4 setup on its own (hence the "selling both the Denon X3800H and Classe Audio CA-5200").

Now I know where you live, I think I can shed some more light on the matter.

Norway is 230 volts 50 cycles per second, and uses Type F wall plugs.

Now, the problem with those plugs is that the live and neutral pins can be reversed. The ground plugs are top and bottom.

Now I would bet the Denon is double insulated and mixing this polarity up will not matter to that unit, but I can not be certain of that. However I bet that the Classe unit does not like polarity reversal.

So reverse the plug on the Classe and see if the hum stops. If not reverse the Denon plug as well. If you still have hum reverse the Classe plug again. One of those combinations could do the trick for you. That F plug is a weird contrivance and a bad idea. A lot of audio gear is not designed to have the live and neutral connections reversed.

 

[Hobolicious]

Now I know where you live, I think I can shed some more light on the matter.

Norway is 230 volts 50 cycles per second, and uses Type F wall plugs.

Now, the problem with those plugs is that the live and neutral pins can be reversed. The ground plugs are top and bottom.

Now I would bet the Denon is double insulated and mixing this polarity up will not matter to that unit, but I can not be certain of that. However I bet that the Classe unit does not like polarity reversal.

So reverse the plug on the Classe and see if the hum stops. If not reverse the Denon plug as well. If you still have hum reverse the Classe plug again. One of those combinations could do the trick for you. That F plug is a weird contrivance and a bad idea. A lot of audio gear is not designed to have the live and neutral connections reversed.

Good suggestion, and actually something I have tried in the past. I did however try it again now, but unfortunately no combination of turning the power plugs made any difference.

 

[TLS Guy]

Good suggestion, and actually something I have tried in the past. I did however try it again now, but unfortunately no combination of turning the power plugs made any difference.

So, one of those units, probably the Classe, has a poorly designed ground plane. So, I would bond the chassis of the Denon and Classe together and just ground one.

Your other option would be to convert the preouts of the Denon to balanced and use the XLR connectors of the Classe, but only connect the shield at one end of the balanced cables. You probably should look for an active converter though. You will need one that runs on 230 volts though.

 

[Hobolicious]

So, one of those units, probably the Classe, has a poorly designed ground plane. So, I would bond the chassis of the Denon and Classe together and just ground one.

Your other option would be to convert the preouts of the Denon to balanced and use the XLR connectors of the Classe, but only connect the shield at one end of the balanced cables. You probably should look for an active converter though. You will need one that runs on 230 volts though.

Could you explain this in layman's terms for me?

How exactly would I go about doing the first option? I assume what I have been trying to do with the speaker cable running between the two units (mounted behind a screw on each of them) is not really the way to do this. Will you have to do anything to the power plug of one of the units, and is this safe?

As for the other option, what do you mean by converting the pre out of the Denon to be balanced? I thought it was not possible to make the unbalanced RCA pre-outs balanced? What would an active convert be? Is this in combination with the "balanced cables"?

 

[PENG]

Like the Jensen Iso-Max CI-1RR? That was at least something I stumbled across when trying to look up signal ground isolators, but it seemed very expensive (considering I would need a few of them).

I know there are quite cheap RCA Ground Loop Isolators that are probably frowned upon, but I am not sure if it might be worth a shot considering they are like 10-15 USD or so a piece?

Good ones are expensive, cheap ones may degrade signal quality. You really should try the rca to xlr cables I link and see if they can do the trick. It is still possible there is something wrong with the Denon or the ca-5200, more likely the ca-5200 because the Denon is young and brand new.

Is that Jensen devices returnable with x number of days?

 

[PENG]

RCA to XLR cables will do nothing.

Not true, it could do a lot, did you read the Hypex article that has been posted on ASR many times? The theory is sound.

 

[PENG]

So long as it's not done with a cheater plug

Ground Loops - Eliminating System Hum and Buzz

Got an annoying hum or buzz in your audio system? You likely have a ground loop. This article helps you diagnose the problem so it can be eliminated. Don't put up with hum. Read this article!

www.audioholics.com

Haha, I am a professional EE, it would be against ethics to use cheater plugs, so no not recommended...