Westerml Posted February 5, 2023 Share Posted February 5, 2023 Hey All…Anyone ever have a noise/ground issue with your, XILICA? My situation outlined below: SET UP XILICA XD8080 set up in 2-way configuration with all single-ended/RCA connections at amplifiers. All amps have 3-wire AC plugs. XILICA, outputs are the phoenix connector (see picture) wired with the shield wire tied to the “G” terminal; center RCA pin to +; outer RCA ring to -. Assume RCA plug wiring at amplifier connection is; RCA center pin “red”; RCA outer ring tied to “shield” and “white“ wire as typical with an RCA interconnect. ISSUE Ground loop issue creating noise in my LaScala 15 and my axi2050 drivers on K402’s. Noise on low and high channels Noise on high channel/axi’s an intolerable high frequency ring around 1.5K. Noise on LaScala 15 more typical of a lower frequency ground noise. STEPS TAKEN SO FAR Separated components AC on separate circuits to try and identify house loop issue. Shut off potential house branch circuits/breakers to isolate potential issue of lights, inverters, etc. ”Lifted” ground on low end amp and it eliminated most of the ground noise. Low end/LaScala 15 noise tolerable but not super clean. “Lifted” ground on high channel amp and noise still persists through Axi drivers. NOTE: the ground noise in the drivers is across the frequency range but is intolerable at around 1.5K. A ring that is not acceptable. Different amps get the same issue. i.e. it’s not the amplifiers. MY INTIAL THOUGHTS Ground noise is back-feeding from interconnect shield wire? The RCA connection end on the amplifier end has the shield wire connected to the outer ring on the RCA Jack. The shield wire on interconnect is connected to the G terminal at, XILICA creating the back-feed path. Should the shield wire be left Open at the XILICA? Or should it be tied to the “-“ terminal on the XILICA with the RCA outer ring? Any suggestions appreciated. I can easily drop the shield at XILICA or tie shield to “-“ at XILICA and test this but I do not want to damage my XILICA or my drivers and hoping for some feedback from group. Thanks as always, Mike Quote Link to comment Share on other sites More sharing options...
LTusler Posted February 5, 2023 Share Posted February 5, 2023 Try disconnecting the shield at the RCA end. 1 Quote Link to comment Share on other sites More sharing options...
Westerml Posted February 5, 2023 Author Share Posted February 5, 2023 Thanks, @LTusler . Thanks for the suggestion. The hassle with that is it would mean opening up RCA connector at the amp side and breaking the shield wire away from connector. Not a huge deal but PIA. That’s why I was thinking to either disconnect shield at XILICA or tie it to “-“ on XILICA so any ground issues would follow to amp side and go to ground. I am no grounding expert but does that make sense. Or should it all end up grounding at the XILICA?…I have not tried lifting the ground on my XILICA and really don’t want to do this with all the sensitive electronic items/chips/etc. in XILICA. …hmmmm Quote Link to comment Share on other sites More sharing options...
babadono Posted February 6, 2023 Share Posted February 6, 2023 Unbalanced input (RCA) will not work with shield disconnected. There will be no return path for signal current. I am still not clear which Monoprice cable you are trying to use. Please paste a link to it. You responded in a PM that it is TS. I don't know what that is. Twisted/shielded? Tip/sleeve? or? Do not lift the ground on the Xilica. It is a pro piece of gear and should work perfectly with a grounded power connection. And you for sure do not want to lift both pieces unless they are on a GFI circuit which is more trouble than it is worth on audio gear. And again as I stated in our PMs ...you may need to go as far as a ground isolator...you may not have a ground loop per se but it maybe CIC problem. Common Impedance Coupling. The Jensen ISO MAX will alleviate that problem also. And if you order from Jensen do yourself a favor and get a pair of their "dummy plugs". Quote Link to comment Share on other sites More sharing options...
LTusler Posted February 6, 2023 Share Posted February 6, 2023 Looks to me like the +/Red wire should go to the TIP, and the -/White wire should go to the RING and the shield should only be connected at the Xillica end. I believe that's how a proper Balanced to Unbalanced connector is wired. If the shield is connected at both ends, it may become an antenna and pick up noise. https://community.klipsch.com/uploads/monthly_2018_07/RCAtoXLR.JPG.3b21471841127942894f71bf0eefaa8d.JPG Quote Link to comment Share on other sites More sharing options...
babadono Posted February 6, 2023 Share Posted February 6, 2023 Respectfully.....if it is a balanced cable meaning twisted pair with shield the diagram above is wrong. It only shows a 2 wire plus shield in one of the diagrams and is therefore misleading. You must think in terms of where the inter chassis current will flow between the pieces of equipment. You do not want that current flowing down the same conductor as the signal ground/return current if at all possible. Quote Link to comment Share on other sites More sharing options...
Westerml Posted February 7, 2023 Author Share Posted February 7, 2023 (edited) Thanks everyone. Monoprice cables I am using https://www.monoprice.com/product?p_id=4776 Will not lift ground on XILICA. I did try tying the negative and shield together at XILICA as recommended by XILICA and as shown below. It did not solve the issue. Update: I am now using balanced connections to high end amp. Quiet, no noise obviously. The ground noise still persists in the low end which is still single-ended configuration. So same problem. Got it on the Jensen. Not cheap and currently back ordered at PE. Mike Please try the following wiring instructions and let me know if this remedies the noise. -Mark Xilica® Global Customer Relations Edited February 7, 2023 by Westerml Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 7, 2023 Share Posted February 7, 2023 3 hours ago, Westerml said: Thanks everyone. Monoprice cables I am using https://www.monoprice.com/product?p_id=4776 Will not lift ground on XILICA. I did try tying the negative and shield together at XILICA as recommended by XILICA and as shown below. It did not solve the issue. Update: I am now using balanced connections to high end amp. Quiet, no noise obviously. The ground noise still persists in the low end which is still single-ended configuration. So same problem. Got it on the Jensen. Not cheap and currently back ordered at PE. Mike Please try the following wiring instructions and let me know if this remedies the noise. -Mark Xilica® Global Customer Relations If you haven’t already then you might try leaving the cable configured as xilica suggested and then run a single separate wire between the xilica and unbalanced amplifier’s chassis and see if that helps. Definitely plug the xilica and amplifiers into the same AC Outlet Circuit. What model is the single ended amplifier your using…? What model is your pre-amp…? And about where are you able to set the Volume Control for normal listening levels…? miketn Quote Link to comment Share on other sites More sharing options...
Westerml Posted February 8, 2023 Author Share Posted February 8, 2023 Thanks @mikebse2a3 1 hour ago, mikebse2a3 said: If you haven’t already then you might try leaving the cable configured as xilica suggested and then run a single separate wire between the xilica and unbalanced amplifier’s chassis and see if that helps. Definitely plug the xilica and amplifiers into the same AC Outlet Circuit. What model is the single ended amplifier your using…? What model is your pre-amp…? And about where are you able to set the Volume Control for normal listening levels…? miketn I will try the chassis wire. Great idea. XILICA, is not in the same outlet or even on the same circuit for that matter. I will rectify this. Amp is a Conrad Johnson MF2500. All caps are good and amp is in good shape. 26dB gain Preamp is also a Motif (also CJ) MC 10. Also, in good shape. Volume control on preamp is 9 o’clock. 10 max. Note: I lifted the amp ground and silenced the low ground noise. But it still has a very faint high frequency ground noise ring. Coming through the 15 I guess. Never heard this before. Thanks Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9, 2023 Share Posted February 9, 2023 On 2/7/2023 at 12:17 PM, Westerml said: I did try tying the negative and shield together at XILICA as recommended by XILICA and as shown below. It did not solve the issue. How could it? Again you MUST(not speaking only to you but any and all) think about where the inter-chassis current is going to flow and keep that off the signal ground conductor as best as possible. https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf This doc has a ton of GREAT info from the MAN himself Bill Whitlock former president of Jensen Transformers. CAUTION there is science and engineering and physics and stuff like that involved. Not vodoo and snake oil. Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9, 2023 Share Posted February 9, 2023 On 2/7/2023 at 12:17 PM, Westerml said: Thanks everyone. Monoprice cables I am using https://www.monoprice.com/product?p_id=4776 OK cool... Curious when you loped off the XLR end did you make sure that you still had continuity between the shield and the conductor that you are connecting to the Xilica minus output? And they both should connect to the RCA outer contact. This is the way cables like this need to be wired and I know for sure when I was buying them that they were made that way...but if Monoprice has changed their production which they could...well anyway it is worth checking. 1 Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9, 2023 Share Posted February 9, 2023 " a cable is a potential problem connecting to 2 other potential sources of problems" Quote Link to comment Share on other sites More sharing options...
babadono Posted February 9, 2023 Share Posted February 9, 2023 This is how I solved the "adding unbalanced gear into a balanced system" Basically installed An ISO MAX box inside for balanced inputs and added impedance balanced outputs. 1 Quote Link to comment Share on other sites More sharing options...
Westerml Posted February 10, 2023 Author Share Posted February 10, 2023 Thanks @babadonoGreat idea to ring out wires. Especially in this supply chain climate…. would love to hear that range expander. All roads lead to the old DBX stuff. Classic. Great work. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 10, 2023 Share Posted February 10, 2023 The Bill Whitlock article that @babadono posted is a great source for information. I also wanted to post 3 papers by RANE that helps to understand the issues and possible cable wiring methods that might help when going from Balanced and Unbalanced interfaces. It should be noted that High Quality Isolation Transformers (Preferably “INPUT” type being best when possible) like the ISO-MAX by Jensen for example are the best solutions but cable wiring methods “might” meet your requirements especially if cost is a consideration. Sound_System_Interconnection.pdf Grounding_&_Shielding_of_Audio_Devices.pdf balanced-unbalanced_revised.pdf miketn 1 1 Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 10, 2023 Share Posted February 10, 2023 23 hours ago, babadono said: This is how I solved the "adding unbalanced gear into a balanced system" Basically installed An ISO MAX box inside for balanced inputs and added impedance balanced outputs. @babadono great job…!!! I bought the DBX 4BX when it first came out and found that it helped on almost all recordings except for the very best examples and even on them the Impact Restoration especially on drums and such added much to the realism I experienced. miketn 👍 Quote Link to comment Share on other sites More sharing options...
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