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Post by jinster on Aug 26, 2020 19:59:28 GMT -5
Hello everyone. I just bought an XPA-2 Gen 3 after reading about all the hype. It's coupled to a Yamaha RX-V2081 AVR. While I am a bit disappointed with the XPA-2 in terms of 2 channel music performance (compared to just using the Yamaha rated at 140watts), I am very happy with the added grunt when it comes to watching multi-channel atmos movies - with the XPA powering the main fronts, and the Yamaha powering all the rest.
Anyway, the problem, is that I can hear a tweeter hiss/hum/rapid click from my 6-ohm 89dB Yamaha NS-F901 speakers when they are connected to the Emotiva. They don't make a noise when just connected directly to the Yamaha.
The noise is only audible when I put my ear at 50cm from the tweeter.
Disconnecting the RCA cables at the Yamaha end - upstream the Emotiva, still shows noise. It's only by disconnecting the RCA cables at the Emotiva end does the noise go away.
So it seems it's the RCA cables that are causing the hiss.
Except I have tried two pairs of 50cm premium shielded RCA cables (split apart) and they produce the same result... I've got a friend to "move" the RCA cable around (attached to the Emotiva but disconnected to the Yamaha) as I listened at the tweeter - the loudness and "quality" of the hiss does change a bit as the RCA cables move....
Any advice on what to do next? Would getting a pair of RCA interconnects with ferite beads help?
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Post by 405x5 on Aug 27, 2020 13:44:44 GMT -5
Something else in your “chain of command” in all likelihood. That does not sound like a cable issue to me
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Post by leonski on Aug 27, 2020 13:51:22 GMT -5
I've heard of people using a SHIELDED cable for RCA. 2 interior conductors, one of which is 'ground' AND a shield connected to chases at ONE end.....I think the 'sending' end. RFI drains to the chassis....
At least that's the idea.
Are your split pair REALLY shielded and if so, is the shield connected at BOTH ends?
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Post by jinster on Aug 28, 2020 2:09:13 GMT -5
Something else in your “chain of command” in all likelihood. That does not sound like a cable issue to me Sorry if I wasn't clear. It has to be the RCA cables. Or the interaction between the RCA cables and the Emotiva/Speaker combo.... Speakers + Emotiva + free hanging RCA (nothing connected to the other end of the RCA) = noise Speakers + Emotiva without any RCA cables attached = no noise There isn't anything else in the chain in these two scenarios.... With regards to the Yamaha AVR, I was simply saying if I go Speakers-Yamaha AVR without Emotiva + RCA in between, there is no noise in the speakers either.... |
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Post by jinster on Aug 28, 2020 2:11:55 GMT -5
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Post by 405x5 on Aug 28, 2020 7:16:33 GMT -5
“the problem, is that I can hear a tweeter hiss/hum/rapid click from my 6-ohm 89dB Yamaha NS-F901 speakers when they are connected to the Emotiva. They don't make a noise when just connected directly to the Yamaha.” Whatever’s going on here, swapping interconnects will not change it |
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Post by Ex_Vintage on Aug 28, 2020 8:12:06 GMT -5
Unterminated RCA cable connected to the input of your amp is an effective antenna. Check to see if the hiss is there when you short the input to the RCA cable. My guess is its quiet if you do that. The cable is not "creating" noise, it may be an antenna picking up EMI from another source.
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Post by 405x5 on Aug 28, 2020 11:00:22 GMT -5
Unterminated RCA cable connected to the input of your amp is an effective antenna. Check to see if the hiss is there when you short the input to the RCA cable. My guess is its quiet if you do that. The cable is not "creating" noise, it may be an antenna picking up EMI from another source. That’s possible but not only that....very bad idea having RCA’ s plugged in at one end and going NOWHERE while the power is on....touch the wrong way and a loudspeaker driver could become history in a hurry. Perhaps a sensitivity issue between the Emo. amp. and the receiver amplification. |
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Post by leonski on Aug 28, 2020 17:56:15 GMT -5
“the problem, is that I can hear a tweeter hiss/hum/rapid click from my 6-ohm 89dB Yamaha NS-F901 speakers when they are connected to the Emotiva. They don't make a noise when just connected directly to the Yamaha.” Whatever’s going on here, swapping interconnects will not change it IF the cable is shielded AND 2 interior conductors? chances are the shield is connected at BOTH ends which does you little or no good. See other posts for ideas about 'Antenna'. One solution is a DIY cable with the SHIELD connected ONLY at one end. Usually the 'sending' end so any RFI picked up goes to chassis ground at the preamp. Something like Mogami 2549 which has 2x 22ga internal and a SHIELD around 'em both. This is where you get the idea of 'directional' cables. www.markertek.com/product/2549/mogami-2549-2-conductor-microphone-cable-22awg-per-foot-black |
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Post by jinster on Aug 28, 2020 23:06:56 GMT -5
Unterminated RCA cable connected to the input of your amp is an effective antenna. Check to see if the hiss is there when you short the input to the RCA cable. My guess is its quiet if you do that. The cable is not "creating" noise, it may be an antenna picking up EMI from another source. Thanks, Ex Vintage, for the suggestion. This makes sense. When you say "short the input to the RCA", do you mean connecting the tip (centre pin) and the sleeve (outer connector) together for each individual RCA? That won't damage the amp, will it? I can try that when I get home. The RCA cable picking up EMI as an antenna idea is sound. But isn't that exactly why the good RCA cables (which is what I have) are shielded? The setup includes the Emotiva amp, Yamaha AVR, an Epson projector, and a Nvidia Shield. There are wires everywhere.... is there a way I can shield the RCA cables in addition to their built-in shielding? Just for clarity, 405xx5, the RCA cables are only free hanging on the other end as a diagnostic exercise - to rule out the pre-amp section of the AVR being the cause of the hiss. In normal use, it is obviously connected to the AVR pre-outs. |
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Post by 405x5 on Aug 29, 2020 12:38:21 GMT -5
How noticeable is this during normal listening? Earlier I mentioned “sensitivity”. If there’s a big spread between your two amplification sources it would easily explain what it is you are hearing.
Bill
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Post by Ex_Vintage on Aug 31, 2020 22:15:36 GMT -5
Unterminated RCA cable connected to the input of your amp is an effective antenna. Check to see if the hiss is there when you short the input to the RCA cable. My guess is its quiet if you do that. The cable is not "creating" noise, it may be an antenna picking up EMI from another source. Thanks, Ex Vintage, for the suggestion. This makes sense. When you say "short the input to the RCA", do you mean connecting the tip (centre pin) and the sleeve (outer connector) together for each individual RCA? That won't damage the amp, will it? I can try that when I get home. The RCA cable picking up EMI as an antenna idea is sound. But isn't that exactly why the good RCA cables (which is what I have) are shielded? The setup includes the Emotiva amp, Yamaha AVR, an Epson projector, and a Nvidia Shield. There are wires everywhere.... is there a way I can shield the RCA cables in addition to their built-in shielding? Just for clarity, 405xx5, the RCA cables are only free hanging on the other end as a diagnostic exercise - to rule out the pre-amp section of the AVR being the cause of the hiss. In normal use, it is obviously connected to the AVR pre-outs. Yes, short the center pin to the outer connection shroud. This is OK for the amp because it should guarantee 0 volts input to the amp. This should verify if the cable is good. Also, a ohm check of the cables should verify continuity. One issue may be that, in the AVR, the pre-amp is not disconnected from the amp section when you use the pre-out connections. 2 amps in parallel with different power supply topologies may create noise issues. |
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Post by leonski on Dec 19, 2020 22:53:19 GMT -5
How'd this finally shake out?
Did you find out that the cable in question really does Not have a 3rd wire as shield? That'd be my guess.
Any cure for this?
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Post by 405x5 on Dec 20, 2020 13:15:53 GMT -5
How'd this finally shake out? Did you find out that the cable in question really does Not have a 3rd wire as shield? That'd be my guess. Any cure for this? At my age.... I’m happy to hear hiss (or anything else) Bill |
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Post by leonski on Dec 20, 2020 14:06:45 GMT -5
How'd this finally shake out? Did you find out that the cable in question really does Not have a 3rd wire as shield? That'd be my guess. Any cure for this? At my age.... I’m happy to hear hiss (or anything else) Bill My EARS are generally OK. I'm worried about my EYES. I still don't quite need glasses to DRIVE (legally) but it will come to that eventually. I'm a photographer and glasses are a PIA. Eyepiece on camera has a diopter adjust so I can do that. I RARELY use the LCD screen. Autofocus works well, but I frequentyly 'fine tune'. NO hiss in my system, even with no signal / turned UP |
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Post by 405x5 on Dec 20, 2020 15:01:41 GMT -5
At my age.... I’m happy to hear hiss (or anything else) Bill “NO hiss in my system, even with no signal / turned UP” The only time I was dealing with anything less than dead quiet was back in the record player days. More, or less depending on how well your tonearm/cartridge dealt with resonance and hum, etc. |
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