Low buzzing through speaks

The old amp did not moan and hum, so I doubt that changing the whole home’s wiring is going to be easier than chucking in the old amp.

The two most common sources of new/increased noise when things were fine before, is an amp with more gain or a more efficient pair of loudspeakers.

I don’t know if there a more irritating noise than hum unless it is static. I can even live with a little hiss. This is too common of a problem in audio. The cure or reduction of it can be anything from changing a cable or two, to rewiring the house!

The old amp did not moan and hum, so I doubt that changing the whole home’s wiring is going to be easier than chucking in the old amp.

And if it did not hum with the old cables, then why is it humming with the new cables?

And then if the new amp hums elsewhere, we might have a datapoint to understand if it is the new amp.

But it is possible that it is as simple as a power cord over an IC, but I assume that the OP has addressed that via some investigation, and cable jiggling.

I don't know if there a more irritating noise than hum unless it is static. I can even live with a little hiss. This is too common of a problem in audio. The cure or reduction of it can be anything from changing a cable or two, to rewiring the house!

Again it is faint and you have to put your ear up to the speaks to hear but it is definitely there.

• Maybe just try and ignore it, and keep the ear away from the speaker?
• Or downgrade back to the old amp?

I just went around with this same problem. 

At full volume with no source playing I was getting 48.5 dB hum and hiss from each speaker. Loud.

I finally traced it down to the subwoofer rca cables. I put in a different and better made cable and my hum and hiss went from 48.5 dB down to 35.4 dB. Wow!! that was a 13 dB attenuation of garbage noise! What an impact on the noise floor.

Apparently it was doing a weird backfeed through the the preamp outputs I was using to drive the subs...

Any update?

So, @russ69 ​​​​​and @dpop the XLR ground lift adapters did not do anything, which I'm almost glad because wow were they a bi%$h to get in! The attenuators are arriving today via UPS. Let's see if they do anything. If not, I'm still going to try the RCA's just for kicks but that might be it (still may try the ground wire @dpop)...

Regardless as I've said this journey has been worth every second just because of all of you reaching out and taking much of your time to help and support😌...

Thank you again all for staying the course with me😊! @davidrolon thanks for sharing your issue, my router is on another floor so it’s totally separate from the system..

@russ69 ​​​​@dpop just an update, the ground lift adapter and attenuator are arriving today…I’ll report back as soon as I get them and install. I am concerned about signal quality but at this point since they’re already on their way gotta try them, right?😬

I had a similar problem. Turns out it was my wifi router. Problem went away when I moved the wifi router further away. 

Don't know of any specific pre-made cables that would be up to the job, but I'd be surprised if custom / "premium" cable manufacturers would not offer options for ground lift on balanced cables. Considering your technical capabilities, just using RCA interconnects might be the best solution for you. 

Thanks for clarifying @sleepwalker65 unfortunately that is so far over my skillset I wouldn't even know where to start. Are there any other already made XLR's that you know of that could solve this issue?

You can correct the XLR wiring to lift the shield ground at the power amplifier end of the cable. That should be the correct and final solution. It will require that you modify the wiring on your custom XLR cables. 

@kingbr 

You are most welcome. 

Usually most if not all Mac amps such as their monoblock amps and most of their stereo power amps are fully balanced design or true differential design but not sure about their entry level AV preamp surround processors such as your MX122, whish was based on the Marantz AV8802. Mac's flagship AV preamp surround processors such as as the MX 160/161/170 are most likely fully balanced design or true differential design. I have no clue regarding your Simaudio Titan multi-channel amp. 

Just enjoy your music and movies and forget about that faint buzz that's only noticeable from couple inches away from your speaker. 

Thank you @sleepwalker65 , so are you suggesting I go to RCA IC's? 

@dilatante great point on the fully balanced. I am pretty sure both the Mac and Sim are fully balanced, I know the Sim is actually and I have to believe the Mac is as well...

Thank you @dilatante and definitely noted. You all make such great cases and like I said above because of so many thoughtful, helpful, insightful, and supportive replies from all of you the outcome is now secondary and if I live with it, I will sleep much better at night and not worry about it anymore. The positivity and great support has truly been not a silver lining, a gold one! Wish I could do more but a deep sincere thank you is the most I can so humbly offer...

I already have the attenuator and ground lifter (I think they may have just arrived) so I might as well try and see? But I will now listen more closely once they're in to see if I lose any signal purity. I can always return them. Knowing this is so common and that so many live with it, and yes that mine is so inaudible except ear to tweet, I have now started to enter acceptance phase😂😁🤣. And though I can't "unhear it" (love that one @dilatante😁), I can really now wrap my brain around it thanks to all of you...

@kingbr circling back to the interconnect cables between the preamp and power amp, I have a new angle to look into. As you know, XLR plugs have three pins. Two are for the balanced signal, and the third is for the signal ground. You will also note that the XLR connector body (also known as the connector shell) is typically made of metal, and is therefore conductive to electricity. 
 

There is a golden rule in electronics to only use one path for any signal. Ground connections are often the most difficult to control, because there are different approaches to grounding. But for the sake of this discussion, let's leave it at the golden rule. Normally we consider the preamplifier in a HiFi system to be the place where all grounds originate. Therefore the other things (such as your power amplifier) should not allow a circuit to form through the shield ground, which is normally also the chassis ground. You will want to also keep the signal ground separated from chassis ground at all points from the preamp to the power amp. The shield is supposed to be electrically connected to only the chassis ground of the preamp. It must not be connected to the XLR connector shell at the power amp, or an undesirable current will flow through the shield, causing that buzzing noise you hear in your speakers. 

But I would just keep using the XLR balanced interconnects throughout especially if your gears are fully balanced design or true differential design internally. I don’t know if your Mac and Sim are true differential design or fully balanced design internally, but if they were, you will be better off using XLR cables throughout as it would sound better than using RCA single ended cables. it’s quieter (lower noise floor) when using XLR cables if your gears are fully balanced design or true differential design internally.

FYI, not all gears that provide XLR connectivity are fully balanced design or true differential design internally. Some are single ended design internally although they provide XLR connectivity (outputs & inputs). Marantz multi-channel power amps and their preamp surround processors are single ended design internally but they provide XLR balanced connectivity (inputs & outputs). So if your gears aren’t fully balanced design or true differential design design internally you can use RCA single ended interconnects and would sound the same whether you’re using RCA or XLR, or you would probably be better off using RCA in this case, unless if you're running long interconnects then use XLR cables. 

So it would appear switching to RCS’s won’t make any difference, no?

The RCAs will be 3db down from the XLR connections. 3db might be enough to knock down the hiss a bit. 

Agree with @dpop as it will be tradeoffs because you will be compromising the signal purity thus overall sonic fidelity (sound quality) everytime you insert something in the signal path. 

@kingbr 

I wouldn't get any XLR attenuator or any sort in the signal chain because you will be compromising the overall sound quality of your system slightly. Just leave it the way it is since the faint buzz is only noticeable from like couple inches away from the speakers anyway and has no impact on overall sound. Don't sweat it. 

Good point @markmoskow. If it already isn't the case @kingbr, try turning off all lighting in your place, and see if this makes a difference. I also agree with @dilatante. There are sometimes trade-offs in the audio world. In your situation, you will probably be *slightly* compromising the performance of the Transparent's when inserting any other device in them (like the attenuators or XLR shield lifters). Only you can decide what you want to live with. If this was my setup, at some point I would have shorted pins 2 & 3 on one of the XLR cables (at the female end, while plugged into the Sim), to see how much of this is being picked up by the cable alone. 

LED light somewhere in the room, either a 5v or an LED of certain type bulb in traditional socket. Unplug it. See if that is it. 

@kingbr

You’re very welcome. I know how you feel about that. Once you heard it you cannot unhear it eventhough it’s only audible from inches away from the speaker’s tweeter 😁😁. What’s your speakers’ sensitivity? It’s even more audible through highly sensitive speakers (highly efficient speakers).

You don’t want want to use a ground lift XLR adapter or a 10db XLR attenuator, you don’t want to insert anything in the signal path as it would potentially degrade the signal purity thus will degrade and compromise the overall sound quality. Just leave it alone as is. Because you will be compromising the overall sonic fidelity (sound quality) while trying to fix or resolve something (faint buzz that’s only audible from couple inches away from your speaker’s tweeter) that isn’t even an issue to begin with.

Not all systems are dead quiet if you literally put your ear right up to the speaker due to various different AC induced environments in our homes. But it looks like you have the Shunyata AC power product and power cables in your setup. Shunyata makes great AC power products and power cables. I also use Shunyata AC power products and power cables in my setup at home but that faint buzz is still there when I use my Cary SA 200.2 ES power amp in the system, but then when I switch the amp back to the Classe amp the faint buzz goes away and is dead quiet. So, I know it’s the Cary SA 200,2 ES power amp (solid state) that’s causing that’s causing that faint buzz when I put my ear right up to the speaker (really close to the speaker). So, I just live with it since the Cary sounds better and more musical than my Classe Sigma Amp2 power amp. But I still have the Classe amp and decided to keep it as a back up amp (reserve). I mostly use the Cary amp since I like the way it sounds as it reminds me a bit of its tube amp counterpart since Cary Audio is well known for their tube gears. I have their SLP-05 vacuum tube linestage preamp in my setup and they make great combo. I only have stereo setup for listening to music only. I don’t do surround sound movies.

Trust me kingbr, just leave it as is and just relax and enjoy your music and movies.

RCA’s should say

@russ69 ​​​​@dpop just read this in the Titan owner manual:

The gain in each channel is the same among all balanced inputs and among all unbalanced inputs, but NOT the same among balanced and unbalanced inputs. Keep this in mind when level matching, if you are using a combination of both types of inputs.

So it would appear switching to RCS’s won’t make any difference, no?

And thank you @russ69!. I know I’d still have plenty of volume to listen as loudly as my Maiden proofed ears can handle! I was asking if maybe I needed the 20db’s if the gain difference was that vast…

You know something @dpop ​​​​@russ69, I was just thinking about all of this and honestly if at the end of all of this my system is still possessed by this evil entity, you all turned this into an amazingly positive experience. Honestly. Regardless of outcome you have turned my shock and horror into a true positive experience. That will be my take away from this. So thank you, sincerely…😊👌🏻

Wow! Lots of great info @dpop! Thank you again for taking so much time going over these manuals and for being so “invested” in helping. Wish I could repay you somehow…

From what I understand (could very easily be wrong) Transparent utilizes the network boxes on their cables for “calibrating and shielding”. Not sure if they actually do anything but they look cool and it seems they go the extra mile with their cables. Plus they’re local to me here in New England which also attracted me to them initially but the affect they had on my system is when I became loyal.

Thank you for pointing out the volume as I actually do listen quite loudly, so good to know ahead of time about this as that would have completely escaped me and I’d have freaked a bit wondering why I now had to turn up the volume more (64 is what I set the volume at in 2 channel when I listen-if 5 Iron Maiden concerts hasn’t made me totally deaf by now I don’t think this can do much more damage😂🤘🏻). I had no idea or paid any attention to the Volume Limit adjustment. If I recall I think I may have even set that to off? Could be wrong but I’ll certainly try playing with that-great call and great tip!

So tomorrow the ground lift adapters arrive and Friday the 10db attenuator arrives. If neither of these 2 work, next try will be swapping the XLR’s for RCA’s. And thanks for being so proactive I was actually going to ask whether to put them on the Mac or Sim end!

So the Mac is literally double the output gain of the Marantz, so just maybe this is the issue? In relative terms is that a big difference, enough to wreak a little havoc? Keep in mind the Sim is 20 years old. I did just have her serviced and got a glowing bill of health from Sim and I know they “overbuild” their amps but she’s not a puppy anymore☺️…

I’ll also try hitting mute and see what that does. I do have the mute set to “full”…

Yet again thank you so much for being right there every step on this journey @dpop God knows I’d have never EVER been able to get anywhere near as far without you man…

for every -dB of attenuation (5, 10, 20, etc.) that is used, you’ll lose that in volume when playing your system

In almost all cases you'll have plenty of gain to fully drive the amp.

I would hope that both would be 0.0V with no audio playing, or the volume turned all the way down.

That is very seldom the case. Volume potentiometers knock down the preamps full power output. Once the gain drops below the audible range there is no need for further attenuation. That is why the idle hiss can be audible, there is still gain being passed through the preamp.

There’s also a Mute Level adjustment (-40 dB, -20 dB). I’d also try adjusting that to see if that makes any difference in this noise you’re hearing.

To clarify, I'd also try turning ON the mute (trying either of the settings), to see if this has any effect on the buzz/hiss you're hearing.

@kingbr 

So the only reason I didn’t hear the buzz with the 1 cable plugged in was because it was the rear and I didn’t listen to that one speaker. As I plugged the 2nd rear in that’s when I caught on that as soon as the XLR cable is plugged back in the buzz comes back in that particular speaker/channel…

I did catch that in a previous mention, but thanks for mentioning it again, so everyone reading this can absorb it, if they missed it.

I have always found Transparent cables to be more “my taste” if you will. I have used several others but there just seems to be something extra once I bring in the Transparents.

...and I can respect that @kingbr. In my discussion of cable construction, I’m just wondering what amount of emphasis Transparent incorporates into their balanced interconnect shielding. Looking at their website, I see no display of it, or they don't boast about it. In your particular situation, it would be interesting to see how different XLR cables affect this noise that you’re hearing (possibly then related to shielding performance). I also can understand what @dilatante is mentioning about output gain from the Mac. It might be greater than your Marantz, which may be the reason behind you now hearing the noise with the Mac, compared to the Marantz.

Might a 20db attenuator be needed?

Keep in mind that these fixed attenuators will act like fixed volume controls. I don’t know how loud you play your system, but for every -dB of attenuation (5, 10, 20, etc.) that is used, you’ll lose that in volume when playing your system, so starting off with a -20 dB attenuator (or pad) might be a little high. Starting off with -10 dB attenuators, like @russ69 suggested, would probably be the better choice. Also, in your situation, and because of this noise, I would place them at the Sim inputs, and not the Mac outputs.

I also notice that there’s a Volume Limit adjustment in the Mac (choices are 60, 70 or 80). I might suggest switching between those (as they might be built in pads), and see if that changes anything. There’s also a Mute Level adjustment (-40 dB, -20 dB). I’d also try adjusting that to see if that makes any difference in this noise you’re hearing. It looks like the Marantz has these same setting adjustments.

Looking at the manual, this is the stated output level of the Mac (but at what volume level?):

Rated Output Voltage
2.5V Unbalanced Outputs (Main Zone)
5.0V Balanced Outputs (Main Zone)

Here’s the stated output for the Marantz:

Rated output: Unbalanced RCA pre-output : 1.2 V Balanced XLR pre-output: 2.4 V

I would hope that both would be 0.0V with no audio playing, or the volume turned all the way down.

What I like about power amps with volume/gain controls is that you can balance a system; not allowing a wide open amp when it’s not needed. I’m almost positive you would not be hearing this noise if the Sim had some sort of volume/gain control incorporated into it.

Don’t forget, we’re still interested in hearing if hooking up the RCA cables changes anything.

Hi @dilatante , thank you very much for sharing. And yes what I am getting seems exactly like yours and is through all 5 speakers. @dpop ​​​​@russ69 also believe it is the higher output gain of the Mac/Sim combo. 
 

And yes it can only be heard by putting my ear within about 2 inches of the tweets and is certainly not audible when anything is playing even at low volume. And it certainly cannot be heard from any normal listening position. So it is not intrusive and I know it’s common and many people live with it, but my OCD knowing it’s there when it wasn’t before won’t allow me to let it be until I’ve exhausted all feasible options, you know😬? I have a ground lift XLR adapter arroving tomorrow I’m going to try and then a 10db XLR attenuator arriving Friday. I’m really hoping/thinking one of these just may do the trick🤞🏻🤞🏻🤞🏻! If not, as I’ve mentioned I’ve got St John’s The Evangelist church on standby to send in the exorcist😂! I know that’ll get rid of this evil entity I’m just not up for the mess I’ve seen these things create😂! In all seriousness I know it’s something I can live with and if all else fails I’ll be fine…I literally connected the Mac (bought it used but new to my system) and my brand new 5 Revel’s at the exact same time expecting nirvana and as I was pulling the grills off I heard it😳😳! It was like that scene near the end from Jeepers Creepers when the Creeper literally punches a whole right through the cop-that’s how I felt😳😂

Thank you again for sharing and taking the time to reply👍🏻😊!

@kingbr 

Are you sure what you are hearing is an actual faint buzz, not a hiss coming from the speaker's tweeter? And you only heard it within half a foot away from the speaker, correct? And this only occurs with your Mac but not with the Marantz you had previously? It's possible that the Mac preamp's output gain is higher than that of the Marantz but it still shouldn't be buzzing IMO. 

But if the faint buzz is audible only when you put your ear right up to the speaker I wouldn't sweat it if I were you and as long as it doesn't distract from your listening to music or movies. And you said it isn't audible at all from half a foot away from the loudspeaker. Are the buzz on all speakers or just the front main LR speakers? 

I have exact same experience as you do with my current Cary Audio SA 200.2 ES stereo power amp (solid state). it's a faint buzz and is only noticeable when I put my ear right up to the speaker. This didn't happen when I had the Classe Sigma Amp2 power amp, it was dead silent. But when I swapped the amp to Cary with everything else unchanged I could hear a faint buzz when I put my ear right up to the speaker, and it's only audible within less than a foot away from the speaker. Apparently this faint buzz is pretty common with this Cary SA 200.2 ES amplifier design. I had discussions with other Cary SA 200.2 ES users on different forums and some could notice a faint buzz but some don't. 

I wouldn't sweat it if I were you as long as the faint buzz doesn't grow louder over time and as long as it doesn't distract from your listening to music or watching movies. You aren't alone in this.

Ned??? I have no idea where that came from😂! Damn auto-incorrect!

Thanks again @dpop! I have always found Transparent cables to be more “my taste” if you will. I have used several others but there just seems to be something extra once I bring in the Transparents. I love the speaker cables and IC’s, however I don’t care much for their power cables. On that I’m strictly Shunyata. I have no scientific data to prove any of this, just my ears😬! 
 

The ground adaptor I ordered from Amazon arrived late today so I won’t have a chance to connect that until tomorrow AM. Also the 2 ground lift cables from Parts Express I ordered via the link you sent are arriving tomorrow…I’ll have an update on the Amazon one in the AM and will update also again after trying the 2 cables from Parts X…

So you mentioned Ned that high gain of the Sim amp. Might a 20db attenuator be needed? I did see a few of those while I was browsing?

OK thank you kingbr for confirming.

I know that some of these cable manufacturers charge an arm and a leg for some of their cables (which I will never pay for), but the construction of each, between manufacturers, is not always the same. Where one might put more emphasis on their shields, another may put more emphasis on the conductors carrying the signal (in balanced mode). Unless the cable manufacturer posts pictures of inner cable construction, you really never know what you’re getting until you try them, and how they will perform in your environment. Having already dealt with so much interference in the past (CB’ers, radio station RF, neighborhood ham operators, etc), I know that a well made shielded cable (like a Gotham), and a low impedance star ground system is always what’s needed in my audio systems, and audio systems that I build for others. For me, shielding takes top priority. Next on my list is (low) capacitance. I’ve already found that when I upgrade to a lower capacitance cable, I can almost immediately hear the improvement. I am also fortunate and thankful that I can make my own cables.

Hi @dpop!

No, no volume, no remote with the Sim...

I thought maybe somehow going from the 2 prong Marantz to the 3 prong Mac may have had something to do with it.

Yes, it’s possible that eliminated the possibility of a ground loop. My continued thought here is this is all ground related, but I’m also concerned about 29 dB of wide open uncontrolled gain on the Sim. Correct me if I’m wrong @kingbr there’s no remote control with the Sim, correct? And there’s no volume control of any sort on it, yes?

I thought maybe somehow going from the 2 prong Marantz to the 3 prong Mac may have had something to do with it. I had no idea how or why that would have an affect but it was something I thought could be playing a role…

Once I got the Sim back and connected it, buzz/hiss gone.

Looking at the rear panel of the Marantz AV8802A, I can’t help but notice that the iec power outlet is only 2 prongs; meaning the unit is technically not seeing an earth ground, until maybe a piece of equipment is plugged into it, *giving it* an earth ground. Really, trying to hook up equipment in the home audio world can be confusing sometimes, because you really have to take into consideration what is grounded, and what isn’t, and these manufacturers don’t make it easy. Not to be condescending, but it sometimes takes some knowledge trying to figure out grounds, and ground loops.

I mix both balanced and unbalanced analog equipment in my home system(s), and you have to know when the time is right to ground, lift shields, or transformer isolate. I admit, it took me years to learn all about this stuff.

I used to live on a very busy street in the days of kids cruising the highway with CB radio’s (man am I dating myself). Believe it or not, they were still heavily using CB’s in the early to mid 90’s (so maybe we’re not going back that far 😉). I was even then routing audio through my townhouse (at the time) using balanced audio, but even still, when they would drive past, their CB signal would many times blare through my system. Well, even at that point in time, I still hadn’t learned all I needed to know about balanced analog audio. So it too took me time to learn about shielding, and grounds, etc. etc. My former neighbor across the alley from me lived across the street from a ham operator, and she used to get so frustrated because his broadcasts many times blared through her TV speaker(s). Now that type of interference is tough to get rid of. Working at the radio stations, I used to get a lot of complaints from neighbors when our signals also permeated their home electronics. Not always easy trying to solve those problems.

It’s very possible attenuators might be needed in kingbr’s case. I’ve used them in broadcast studios, but I think it’s unfair to make homeowners research the need for them in a home audio system environment. One thing that bothers me about the Sim amp is that it doesn’t have any gain controls, so to put it one way, it’s wide open. IMO, that means that any little bit of noise on the interconnects will be magnified more than it needs to be (screwing up your S/N ratio). That’s one of the main reasons why I will never purchase a power amp without gain controls on it. It’s very possible that is what’s taking place here, but again, I think it’s unfair to put a home audio system owner through this frustration when purchasing expensive audio gear.

IMO, both @dpop and @russ69 give you great recommendations, if the XLR ground lift adaptoer works, it will eliminate the hum/buzz noise. Otherwise, an 10dB in-line XLR attenuator will reduce the noise 10dB (since the noise is not affected by the volume control).

https://en.wikipedia.org/wiki/Ground_lift

https://www.parts-express.com/Inline-XLR-Attenuator-Pad-10dB-240-412

You know what is weird? About 1 1/2  years ago I reached out to Simaudio (I bought my Titan amp used 2 years ago and realizing this piece although in amazing condition and was sounding just amazing, it was approaching 20 years) to see what if anything I should do to care for this unit. They recommended sending it to them for "cleaning and calibrating". So I did. Knowing I was going to be without the unit for a few months I bought a Monolith 5 channel amp as a backup (the price was right at $1599 at the time) to get me through. Once I introduced this unit with my Marantz AV8802A, there was a faint hum/buzz - come to have been thinking about it it was very similar to what I have now - but chalked it up to this being a lower end and knowing it wasn't there with the Sim, I wasn't too concerned. Once I got the Sim back and connected it, buzz/hiss gone. I just remembered this today! And from what I recall it was very faint and didn't change volume wise like this current possession of my rig! 

Just maybe the lifters or the attenuators will be the proper exorcism to get rid of this particular evil entity😂🤞

I had this interference both static and hum. The static turned out to be my cell phone and the hum was fixed by better shielded interconnect cables.

BTW, I had this issue with my Mac402 amp. The attenuator did the trick. 

Wouldn't the XLR 10 db attenuator pad attached to each of my XLR cables work?

Yes, it would. 

Hi All, 

So at this point having ordered the 2  Pro Co XLR adaptors referenced by dpop I'm thinking holding off until they arrive before trying anything else at this point. But I may still try the RCA's and see if that does anything? I think the gain on the XLR between the Sim and the Mac sounds like it could be the ticket (but I have absolutely no idea as this is way beyond my limited knowledge here) but hearing the phrase "2 components not playing nicely together" several times this sounds like exactly what is meant? If this is the issue and it seems so many have this kind of issue it's weird that you don't hear much more about it when matching separate amps to separate pre's? You would think this would be publicized more about using caution or being aware of this potential issue, no?

@dpop just PM'd you...

What a whirlwind this has become and @russ69 and @dpop I honestly would describe it is a combo hiss/buzz. Here I am now listening closely like a critical listening session to describe it, LOL!!! That's awesome-still keeping the sense of humor especially after reading that article again from Upscale and the new shot of enthusiasm and hope provided by the incredibly selfless @russ69 ​​​​@dpop! 

Question for @russ69 , why would I need the XLR RCA adaptor in my situation? Wouldn't the XLR 10 db attenuator pad attached to each of my XLR cables work?

try to use caps on the RCA ro XLR, they help to avoid buzz, my own experience. Then everything becomes dead silent, but you don’t need to overdo it, you need to play with them a bit, listen and find your best solution.

Holy $h!t! Wow I just saw all this @russ69 thank you! 
 

@dpop thank you isn’t even nearly enough-I just ordered the last 2 @ Parts Express via the link you sent. I just got home and heading to bed and saw this. Without even looking into it I went and ordered the last 2😂, even after reading that article from Upscale that @russ69 referenced (very powerful article man-thank you). Have to get to bed but will follow up later after some sleep…

Thank you all and @dpop your generosity is off the charts…I’ll pm you later, thank you👍🏻 for your incredibly generous offer!

@russ69 I will admit, some people can describe hiss as buzzing, and confuse the two. So without me sticking my ear against kingbr’s speaker, I can only go on what he’s describing - that he hears a buzz.

@kingbr

Darn it, I just noticed this in one of the reviews of the Hosa ground lifter. The thought of this occurring just hit my brain, and only then did I dig a little deeper and realize someone else had the same concern as I. From a review of the Hosa:

I am VERY disappointed with this product. I bought two of these to use for my studio monitors when trying to debug ground loops, and discovered way too many problems for such a simple product:

== Wired incorrectly ==
First and foremost, this "ground lift" adapter doesn’t even lift the ground... The metal housing is electrically connected to the housing of each each end via the screws on either side. This would be less of a problem if it weren’t for the fact that the connector housing ground is connected to the ground *pin* on both sides. What does that mean? This is just a M to F XLR coupler. Which XLR cables never need.

I fixed this by opening them up, and de-soldering the wire that connects the ground pin to the connector housing. This was not a single mistake; BOTH units had this issue. Unless this is fixed, these are nothing more than a placebo.

I’m really sorry about this. This is frustrating, because I can make exactly what I need in a matter of minutes. I think the Pro Co model is more correct, as it looks like they’re disconnecting one end of the shell from the other (with shrink wrap), which breaks the metal shell ground connection (and pin 1 connection). Sorry, I know this is getting a bit technical now. The problem with the Hosa model, as mentioned above, is a ground connection is still taking place, which rides on the metal outer shell, even though the connection between pins 1 and 1 (on each end of the connector) are disconnected. This was something I was hoping the Hosa model didn’t do. Someone at Hosa designed their product poorly and incorrectly. Yeah, it happens.

Pro Co GLX In-Line XLR Ground Lifter Adapter

Checking stock, it looks like almost everyone on the internet is out of stock on this model (maybe because this one is designed correctly, and actually fixes problems). I’d call Parts Express to see if they can confirm that they actually physically have these on their shelf (the website says they have two in stock). @kingbr private message me with your address, and I’ll make one that I know works, does exactly what I want it too, and I’ll send it to you.

I am going to disconnect XLR’s and try the RCA’s first thing in the AM. Then I’ll try connecting the wire for the ground between the Mac and Sim…

If you have the RCA option, that will be 3db down and might solve your issue, if not see above.