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

[Hobolicious]

Why would you need the X6800H? If it is only for the two extra amp, why not just get that cheap class D amp I linked. Many Denon users have done so and seem happy with them.

Fosi Audio V3 Amplifier Review | Audio Science Review (ASR) Forum

If for some reasons, you don't like it, it is easy to return such a small a light amp.

Yeah, this might also be a possibility. Only reason I said Denon X6800H was because it is a receiver capable of powering all my speakers without the need for an external amplifier (freeing up space in my stand and removing some cables in the setup). What would you typically drive with such an amplifier? The SBL and SBR?

 

[highfigh]

Just so I am certain. On top of cutting the wire to Pin1 (and using electrical tape to cover the cut exposed wire) I also have to desolder and remove the metal pin completely before running the RCA-XLR cable between the two units?

As TLS commented- you only need to separate the wire for Pin1 from the pin. There's no reason to damage the plugs.

Grounding problems can happen everywhere many technical papers that deal with all kind of communications electronics exist. This is so common that searching for 'The Pin 1 Problem' on google shows 830 million links.

 

[TLS Guy]

I see. That is unfortunate. If I remember correctly the cable you linked earlier was a tad short, and couldn’t seem to find a longer version from the same brand. Being in Norway I also have to calculate in the import fees ordering from abroad (as well as the delivery time).

I must admit that I am slowly moving in the direction of thinking that maybe it would be better to move on the Classe Audio CA-5200 while it still holds value, as well as the Denon X3800H, moving over to a Denon X6800H when it become available (cost wise the Classe+X3800H should be somewhat similar in price to the X6800H I would assume). And then long term, if necessary, I could add a 3-channel amp for the front stage (however uncertain if it would be necessary with my Dali Epicon 6 and Dali Epicon Vokal, especially considering the sound levels I am able to play at with two kids in the house).

Moving on would not be because I think the current problem is unsolvable by any means.

Well, you ran deep into the weeds on this one.

The only thing I have to suggest is that I make two correct cables. I have checked my supplies and I only have one Male XLR. I have plenty of RCA plugs. I would also have to order the cap and resistor so we do it by the book. So you would have to wait while I get the parts and then the post to Norway from Eagan MN. It will not take me long to build the cables.

Your other option is to order the correct cables of the right length, which you should be able to find locally and then cut the shield from pin 1 on both cables.

That Classe amp seems a nice piece of kit, that seems a pity to sell on for a trivial problem.

If you are going to own equipment like this, you do need to get more wised up and do some study. Learning how to use a multimeter and soldering skills are part of the basics of owning gear like you have.

 

[Hobolicious]

Well, you ran deep into the weeds on this one.

The only thing I have to suggest is that I make two correct cables. I have checked my supplies and I only have one Male XLR. I have plenty of RCA plugs. I would also have to order the cap and resistor so we do it by the book. So you would have to wait while I get the parts and then the post to Norway from Eagan MN. It will not take me long to build the cables.

Your other option is to order the correct cables of the right length, which you should be able to find locally and then cut the shield from pin 1 on both cables.

That Classe amp seems a nice piece of kit, that seems a pity to sell on for a trivial problem.

If you are going to own equipment like this, you do need to get more wised up and do some study. Learning how to use a multimeter and soldering skills are part of the basics of owning gear like you have.

Just out of curiosity, why do you think I got that large hum with this specific cable (after cutting Pin1)? Is it because of how it is wired on Pin2 (with the red and blue wire being soldered there)?

 

[TLS Guy]

Just out of curiosity, why do you think I got that large hum with this specific cable (after cutting Pin1)? Is it because of how it is wired on Pin2 (with the red and blue wire being soldered there)?

I have no idea, and it would make my head hurt trying to figure it all out. It was the wrong cable with cross connections and too many wires, The cable was designed for pro reinforcement where the set up is double mono to reduce feedback.

 

[Hobolicious]

I have no idea, and it would make my head hurt trying to figure it all out. It was the wrong cable with cross connections and too many wires, The cable was designed for pro reinforcement where the set up is double mono to reduce feedback.

Hehe, understandable. Thanks anyways!

 

[PENG]

Not sure if you saw my pictures above to TSL Guy, but I at least only cut the wire to Pin 1 (and put electrical tape over the now exposed wire). The rest I left as it was. However, TSL Guy said this was the incorrect RCA-XLR (that it was a “dual mono cable”). As per my pictures above there are two wires going to Pin2 (red and blue wires), and then one wire was going to Pin1 (which I cut) and one to Pin3.

No I didn't see it, and I missed that you did not buy one that is wired to the same (or better than) as the Monoprice's diagram below:

It does not have to be Monoprice and I understand you said it was not able in your country, but you should be able to find one like that. I remember posting two links for you to buy from Ghentaudio, or Benchmark, or March Audio (in Australia). Or make your own if you have the basic tools including a soldering iron.

If this diagram, if you still get audible hum that you could try to cut the wire that is soldered from pin1 to the shell., once that's cut, you can see the the signal current will flow in the wires connected to pin2 and pin3 and there is no ground current, except for a very small amount that will always be there, via leakage such as capacitive coupling but that small magnitude should not be audible from you listening position, no system is totally quiet, just a matter or how audible.

 

[PENG]

Yeah, this might also be a possibility. Only reason I said Denon X6800H was because it is a receiver capable of powering all my speakers without the need for an external amplifier (freeing up space in my stand and removing some cables in the setup). What would you typically drive with such an amplifier? The SBL and SBR?

The V3 is almost as powerful as the X3800H if you buy it with the 48 V power supply. With the standard 32 V power supply, you can get about 35-40 W 8 ohms, 65-60 W 4 ohms so in that case you should use it with the surround or height speakers that are the closest to your seat and have the highest sensitivity. There is no good reason not to order it with the 48 V power supply though.

The amp is so small and light, you will have a lot of flexibility to place it, or even hide it from sight.

 

[PENG]

Just out of curiosity, why do you think I got that large hum with this specific cable (after cutting Pin1)? Is it because of how it is wired on Pin2 (with the red and blue wire being soldered there)?

If you compare the cable that I, and TLSGuy referred to, you can see why:

Your cable:

The monoprice cable that we are thought yours were wired the same way, but it's not:

You can see that correct cable that me and @TLS Guy thought you have has pin2 and pin3 for signal, and pin1 is for the shield that is soldered to the shell of the connector.

The wire in the blue ring is the one we suggested you cut, but only if the cable still give you audible hum without cutting. If the hum is much reduced by using such a cable, then leave the pin1 connection there.

 

[PENG]

If you cut the pin1 to shell wire, any ground loop current will be 100% in the signal path, that is the wires connected to pin2 and pin3, that's why you get the loud hum.

 

[Hobolicious]

If you cut the pin1 to shell wire, any ground loop current will be 100% in the signal path, that is the wires connected to pin2 and pin3, that's why you get the loud hum.

I understand that now based on your last image. I had only one wire going to the Pin1 on my incorrectly cables, hence the misunderstanding (there were no connection between Pin1 and the shell of the connector).

 

[Hobolicious]

On a positive note however, even if these cables were not the correct ones, they have really lowered the overall hum (especially if I keep a speaker wire between the two chassis). The only small annoyance is that they introduced the “clicking”/“popping” noise, but it is mainly noticeable when everything is quiet (and still not really loud).

 

[PENG]

I understand that now based on your last image. I had only one wire going to the Pin1 on my incorrectly cables, hence the misunderstanding (there were no connection between Pin1 and the shell of the connector).

Sorry for some reason I missed that myself as somehow I got the impression that you found the equivalent cable in Norway so I never pay close attention to the diagrams you posted. With a quick casual glance they all look the same lol..

Are you sure you cannot get one that is wired like Monoprice's? Did you email Benchmark, March Audio, or Ghent Audio?

Ghent Audio's only $14 for the 3 m, or $12 for 2 m length each so $24 to $28 for a pair:
A15 --- Canare L-4E6S RCA(M) to XLR(M) Cable (ghentaudio.com)

And they show you the connection diagram, same as Monoprice's:

I don't know about the shipping cost but for such light weight small parcel that won't be much. Not sure if they will ship from Shanghai, or Hong Kong, but buckeyeamp used to order enclosures for their hypex amps and I believe he told me delivery to the US was about a week, so you should be able to get it within a week too.

March Audio and Benchmark's likely are of higher build quality but will cost a lot more but here's their claim:

Male XLR to RCA Cable

The NF series are exceptional quality interconnect cables at affordable prices. The NF series is manufactured using Mogami Professional cable and Neutrik / Amphenol connectors. These cables will ensure the absolute integrity of the musical signal from source to destination. Rejecting noise and ensuring a transparent connection, Mogami is considered “the cable of the pros”. Virtually every major recording facility is wired with Mogami.

These cables are specially designed and correctly wired to eliminate the possibility of ground loops when connecting RCA single ended sources to balanced input amplifiers. All March Audio amplifiers are balanced input.

Male XLR to RCA Cable - March Audio

They only make amps with balanced inputs so my confidence level in their immunity to ground loops hum is quite high.

Benchmark's cost seem to be a little more reasonable and I am confident theirs will work just as good as March Audio's. They also only make power amps with balanced inputs.

So you have a choice, going the Fosi Audio amp route is lowest in cost, but then what are you going to do with the very good Classe power amp? It's a touch decision.

For me, I would order both a pair of the RCA to XLR cable from Ghent Audio, and one little Fosi V3 with the 48 V power supply, but you have to decide based on your own rationale.

 

[Hobolicious]

Sorry for some reason I missed that myself as somehow I got the impression that you found the equivalent cable in Norway so I never pay close attention to the diagrams you posted. With a quick casual glance they all look the same lol..

Are you sure you cannot get one that is wired like Monoprice's? Did you email Benchmark, March Audio, or Ghent Audio?

Ghent Audio's only $14 for the 3 m, or $12 for 2 m length each so $24 to $28 for a pair:
A15 --- Canare L-4E6S RCA(M) to XLR(M) Cable (ghentaudio.com)

And they show you the connection diagram, same as Monoprice's:

View attachment 65080

I don't know about the shipping cost but for such light weight small parcel that won't be much. Not sure if they will ship from Shanghai, or Hong Kong, but buckeyeamp order enclosures for their hypex amps and I believe he told me delivery to the US was about a week, so you should be able to get it within a week too.

March Audio and Benchmark's likely are of higher build quality but will cost a lot more but here's their claim:

Male XLR to RCA Cable

The NF series are exceptional quality interconnect cables at affordable prices. The NF series is manufactured using Mogami Professional cable and Neutrik / Amphenol connectors. These cables will ensure the absolute integrity of the musical signal from source to destination. Rejecting noise and ensuring a transparent connection, Mogami is considered “the cable of the pros”. Virtually every major recording facility is wired with Mogami.



Male XLR to RCA Cable - March Audio

They only make amps with balanced inputs so my confidence level in their immunity to ground loops hum is quite high.

Benchmark's cost seem to be a little more reasonable and I am confident theirs will work just as good as March Audio's. They also only make power amps with balanced inputs.

So you have a choice, going the Fosi Audio amp route is lowest in cost, but then what are you going to do with the very good Classe power amp? It's a touch decision.

For me, I would order both a pair of the RCA to XLR cable from Ghent Audio, and one little Fosi V3 with the 48 V power supply, but you have to decide based on your own rationale.

The Benchmark cables are available locally, but only up to 6ft, and cost around 80 USD per cable (so around 240 USD for three cables).

If these are the correct cables from Ghent Audio they would be about 65 USD before import fees. So that would end up being around 95-100 USD (so not horrible). That is for 3 x 10ft cables.

March Audio cables I am unsure about. I believe these would be quite expensive for me to import.

 

[TLS Guy]

The Benchmark cables are available locally, but only up to 6ft, and cost around 80 USD per cable (so around 240 USD for three cables).

If these are the correct cables from Ghent Audio they would be about 65 USD before import fees. So that would end up being around 95-100 USD (so not horrible). That is for 3 x 10ft cables.

March Audio cables I am unsure about. I believe these would be quite expensive for me to import.

Blue Jeans cable, who make very high quality cables will make you 10' cables for $45.00 each. They will make any length you want.

If you want I can price cable and connectors plus the caps and resistors that would remove the remotes safety concerns. I have a lot of RCA connectors in my parts inventory, so that cost would be negligible.

 

[Hobolicious]

Blue Jeans cable, who make very high quality cables will make you 10' cables for $45.00 each. They will make any length you want.

If you want I can price cable and connectors plus the caps and resistors that would remove the remotes safety concerns. I have a lot of RCA connectors in my parts inventory, so that cost would be negligible.

If it would not be too much of a hassle you can at least price what you would take to make three such cables (7-8ft should be enough per cable) and I can think about it?

 

[TLS Guy]

If it would not be too much hassle you can at least price what you would take to make three such cables (7-8ft should be enough per cable) and I can think about it?

RCA plugs $1.63 each.

High quality make Switchcraft connector $5.08 each.

100 nanofarad caps $0.54 each.

100 ohm resistors $1.89 each

Balanced cable $1.09 per foot

Then you will have postage to Norway plus my shipping costs. So it will be in the ballpark of $50.00 for three 7' cables for the parts.

 

[lovinthehd]

I would have just built the cable from the first myself....have done it a few times for such situations. I'm not crazy about using the 6800 instead of 3800 for the cost/effort involved vs simply adding an adequate 2ch amp (too bad the Classe causes noise, but....)

 

[PENG]

If it would not be too much of a hassle you can at least price what you would take to make three such cables (7-8ft should be enough per cable) and I can think about it?

It is very nice of TLSGuy to makethe offer. However, you need find it fun to make the cable yourself.

By tbe way, if you have doubt about the cheaper Ghentaudio cables, why not order one first?

While waiting, you can solder pin1 back on and use those 3 wrong cables, if the hum is not too audible from you seats right?

 

[ban25]

Having the only system in Norway with TLS Guy (TM) cables is probably too good to pass up.

You could get the cables and the Fosi amp together and have a very nice setup.