Low buzzing through speaks

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.

@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.

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.

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.

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…