Analog Inputs & Crosstalk...

[bluescale]

For those of you that don't know, a few of us have noticed that there's an issue with the XMC-1 that sound produced on 1 analog input can be heard in other analog inputs. Here was what I originally posted in the bug thread:

My music server was plugged into analog 3, and I had just switched over to the 7.1 Analog inputs while watching the display shift around. I paused there for a moment, and to my surprise, I could very, very, very faintly hear Time playing. I stuck my ear up against the center channel (I was sitting on the floor right by it at the moment), and sure enough, the music was faintly playing out of the center channel. After some more testing, I've found that if I'm sending a signal to Analog 3, I can hear it bleeding into Analog 2, Record In and Analog 7.1. I cannot hear it in Analog 1 or in any of the digital inputs.

Since then, aviolentgrace has reproduced this behavior, and posted a video showing it in action: 1drv.ms/1q3gzuf

For kicks today, I decided to check to see if I could reproduce the same behavior in my 2 channel system. That system consists of an Olive Symphony music server, a Perpetual technology P3-A DAC, and a Melody SP3 integrated tube amplifier. In other words, a considerably simpler setup than the theater that houses my XMC-1. The SP3 has a rocker switch on the side for two different inputs. When I switched to the second, unused input, played some music, and turned up the volume, I was surprised to find that I have exactly the same behavior. I can hear very soft music coming from my speaker.

My original intention was to set up my test rig and see if can quantify the level of signal bleeding from one input to the other. I might still do that. However, at this point I'm more interested in seeing if people would be willing to test out whether they see this same behavior with their current processor or AVR. Be sure to include what processor your tried this out with. If you have the same model processor as someone else responding, please respond anyway. I want to know how ubiquitous this is across different processors, and within processor families.

[linvincible]

easy fix: turn your unused sources down ;o)

[rogersch]

Sorry but I don't use analog inputs anymore on my surround processor and my AVR @ my computerdesk so I can't test it.

Maybe it might be a good idea for me to buy, or make, shortening plugins for all the non used analog inputs.....

[repeetavx]

Sounds more like bleed through than cross talk. Later I'll have to see if my PT-7030 does this.

[Gary Cook]

If preamps count I'll have a listen to my USP-1 tonight. BTW we don't call it cross talk, to us it's input signal bleed, not that it's important I knew what you meant.

Cheers
Gary

[bluescale]

Good point on crosstalk vs.bleed, guys. In my original post, I think I referred to it as bleed through, but my terminology got mixed up along the way.

Gary Cook - A preamp should be a great test if you get the chance. I used an integrated amp for one of my tests. I was hoping to get some of Emotiva's 2 channel stuff in the mix, as pretty much everyone agrees on the high quality there. It'll give us a good baseline to compare against.

[hemster]

Sept 9, 2014 1:18:46 GMT -5 rogersch said:

Sorry but I don't use analog inputs anymore on my surround processor and my AVR @ my computerdesk so I can't test it.

Maybe it might be a good idea for me to buy, or make, shortening plugins for all the non used analog inputs.....

Be sure to use them on inputs only! They will cause damage when used on outputs. 

If you do decide to build them, here's a guide. Or just buy them, they're cheap enough. Another source here. 

[rogersch]

Thanks for the links.

[bootman]

Sept 9, 2014 1:02:09 GMT -5 linvincible said:

easy fix: turn your unused sources down ;o)

What about if you are using zone 2?

This should not happen at all.

[linvincible]

Sept 9, 2014 6:40:18 GMT -5 bootman said:

Sept 9, 2014 1:02:09 GMT -5 linvincible said:

easy fix: turn your unused sources down ;o)

What about if you are using zone 2?

This should not happen at all.

good one didn't think about it
does it happen to the zone 2 out too?

[bootman]

Sept 9, 2014 6:58:27 GMT -5 linvincible said:

Sept 9, 2014 6:40:18 GMT -5 bootman said:

What about if you are using zone 2?

This should not happen at all.

good one didn't think about it
does it happen to the zone 2 out too?

Here is another one.
Many STB (set top box) are always on. (Tivo, moxi, etc)
If you need to use the stereo outs for these boxes (HDMI issues, etc) then you can be potentially always listening to this source!

This is an easy one to replicate at the Emotiva labs so hopefully a quick resolution is coming.

[tubby]

Just tested my Topping integrated amp. It has bleed into the second input so I gave a Yes for that one.

Next up I will test an old Kenwood unit I have hooked up for my outdoor system.

Edit. Tested the Kenwood. It does it as well. I can only vote once though.

Starting to think it would be unusual if a unit did not do it. Although still strange that my XMC has bleed between different inputs than yours, and why it would only happen between certain inputs and not others. Have you tested to see if you get crosstalk into the surround channels when using 7.1 inputs like I do?

[AudioHTIT]

Sept 9, 2014 10:10:43 GMT -5 tubby said:

Although still strange that my XMC has bleed between different inputs than yours, and why it would only happen between certain inputs and not others.

It actually makes sense that the 'Reference Quality' inputs - Analog 1 and Balanced 1 - are different, presumably they take a different path and circuit.

[bluescale]

Sept 9, 2014 10:10:43 GMT -5 tubby said:

Starting to think it would be unusual if a unit did not do it. Although still strange that my XMC has bleed between different inputs than yours, and why it would only happen between certain inputs and not others. Have you tested to see if you get crosstalk into the surround channels when using 7.1 inputs like I do?

Thanks for testing, Tubby. I have not tested it with anything other than Analog 3. I was going to do more testing last night, but my wife decided we should spend the evening actually enjoying the system rather than playing test tones. What a strange woman .

[edrummereasye]

I know for a fact that I've had other AVR's/pre-amps that did this, including I'm almost positive, my Outlaw 950. Not sure I've ever checked for it on other Emotiva products. However, I'll test if I get a chance, since I still have UMC-1, UMC-200, USP-1, and XSP-1 (I've got too many rooms to ever get rid of anything, lol).

[tubby]

Here is a bit more of a complete test of my XMC. Used my TT as source. I don't have a balance source to test bleed from that input.

A1 input

>A2, very low, max volume ear to the speaker can barely hear it.
>A3,very low, max volume ear to the speaker can barely hear it.
>Rec in,very low, max volume ear to the speaker can barely hear it.
>Ref in, loud, easily hear at MLP
>7.1 in, loud, easily hear at MLP, and in all channels

A2 input

>A1, very low, max volume ear to the speaker can barely hear it.
>A3, loud, easily hear at MLP, and in all channels
>Rec in, loud, easily hear at MLP, and in all channels
>Ref in,inaudible
>7.1 in, loud, easily hear at MLP, and in all channels

A3 input
>A1, very low, max volume ear to the speaker can barely hear it.
>A2, loud, easily hear at MLP, and in all channels
>Rec in, loud, easily hear at MLP, and in all channels
>Ref in, inaudible
>7.1 in, loud, easily hear at MLP, and in all channels

7.1 input
>A1, Loud, easily hear at MLP.
>A2, Inaudible
>A3, Inaudible
>Rec in, Inaudible
>Ref in, Loud, easily hear at MLP
>7.1 in, loud crosstalk to center and surround channels easily heard at MLP

If I get a chance I will go back and test but I think the reason A2 and A3 get bleed to all channels is because PLIix was enabled.

[bluescale]

Sept 9, 2014 12:31:37 GMT -5 edrummereasye said:

However, I'll test if I get a chance, since I still have UMC-1, UMC-200, USP-1, and XSP-1 (I've got too many rooms to ever get rid of anything, lol).

I'd be really, really interested in the XSP-1, since that has a top notch analog section.

[foggy1956]

Would be really nice to hear some feedback on this from Lonnie, but I won't hold my breath

[lionear]

Sept 9, 2014 2:15:01 GMT -5 hemster said:

Sept 9, 2014 1:18:46 GMT -5 rogersch said:

Sorry but I don't use analog inputs anymore on my surround processor and my AVR @ my computerdesk so I can't test it.

Maybe it might be a good idea for me to buy, or make, shortening plugins for all the non used analog inputs.....

Be sure to use them on inputs only! They will cause damage when used on outputs. 

If you do decide to build them, here's a guide. Or just buy them, they're cheap enough. Another source here. 

You don't need to have a resistor, and without one, you can use them on the outputs too:
www.crutchfield.com/S-nScXgAKdVEc/p_703RCANSC/AudioQuest-RCA-Noise-Stopper-Caps.html
www.thecablepro.com/cardas-rf-emi-noise-blocking-caps.html

I made my own stopper caps - and they really improve the sound.

[hemster]

Sept 9, 2014 17:00:05 GMT -5 lionear said:

Sept 9, 2014 2:15:01 GMT -5 hemster said:

Be sure to use them on inputs only! They will cause damage when used on outputs. 

If you do decide to build them, here's a guide. Or just buy them, they're cheap enough. Another source here. 

You don't need to have a resistor, and without one, you can use them on the outputs too:
www.crutchfield.com/S-nScXgAKdVEc/p_703RCANSC/AudioQuest-RCA-Noise-Stopper-Caps.html
www.thecablepro.com/cardas-rf-emi-noise-blocking-caps.html

I made my own stopper caps - and they really improve the sound.

Without the resistor it's a true short but with it there will be issues when used on outputs. Generally there's no need to use them on outputs however because the whole point is to protect against RF interference on inputs. The Cardas units look great BTW.