Chasing a hum is one of the most nerve wracking things you'll ever do. That's what I spent my time on this weekend, the truth of the matter is that I'm not 100% sure if the hum was there before I added the Jolida phono to the PLX system a few weeks ago, it's not my main system. But with adding the Jolida, a Gold v3 and Grado ME+ Mono carts, we've been listening to the system quite a bit. The good news, with the Gold v3 going over 30 hours and giving the Jolida a little time to warm up, things sound amazing.
The "hum" got noticed when adjusting the gain and load of the Jolida, now, way back when, when I had my U-Turn I had a hum, it turned out to be the outlet it was plugged into, so I was convinced it was probably the same thing. I've been wanting to add a surge protector to the system for a while, but didn't wan to spend too much on one, I also wanted to upgrade the power cables, especially on the Jolida, who's stock EIC is a flat ribbon that looks and feels like it cost $.50 to produce. So with those things in mind we decided to wait for this stuff to arrive and see if it remedied the problem. I ordered a pair of Pangea AC14 power cables for the PLX and Jolida, a "generic" heavier power cable for the NAD and a Panamax MR4000 at just over $200.......again, didn't want to spend quite that much, but we pulled the trigger because the MR4300 on the UD system has been working great.
Long story short, we're dealing with a ground loop and not the electrical signal coming in. I've isolated it to the TT, at max volume with the TT off I get a slight hum, still at max volume, once you turn the TT on, it gets kind of loud. Again, we're talking at max volume here. At my normal listening volume albums are dead quiet in all the right places along with the gaps in between tracks and runouts so it's not the end of the world............I just know me, and just knowing it's there makes me crazy. The hum is audible at 12 o'clock on the volume nob from a few feet, my normal listening level is at about 9ish.
With all that being said, the power cables didn't solve the problem, but they did "curb" the hum a bit so between shielding and conductive materials they we're an "upgrade", the higher pitch of the hum came way down and wasn't as annoying. I was also hoping the "conditioning' part of the Panamax MR4000 would help the hum, but it didn't.....this assumption was before the realization of the ground loop.
I even tried eliminating the ground from the TT by using a 3 to 2 prong adapter to see if that would help, no such luck. Between trying other outlets, different cables, surge protectors, changing the ground cable and a bunch of other little things, the best I could achieve was the toned down version of the hum that was there, which I can live with knowing I tried, lol.
So we ended up keeping the power cables for the PLX and Jolida, the power cable for the NAD went back along with the MR4000. The Panamax was replaced with a Tripp Lite surge protector/filter, like the Panamax, the check box I was looking for was the ability for it to shut down all connected devices in case of an overload at a slightly better price with a good warranty from a reputable company.
At the price point of the AC14 cables I would recommend the upgrade at $40 a pop, especially if the stock cable is a ribbon or really thin, the shielding alone makes it worth while in my opinion. The Panamax had nothing wrong with it and I would still highly recommend it, I just didn't want to spend that much on the surge protector for the second system, the Tripp Lite does the job minus the "eye catching" visuals and sits behind my rack instead of in it...........the rack was looking kind of cluttered with the Panamax in there and I was starting to get concerned with too many things sitting on top of the NAD due to it's tendency of getting a little hot and needing room to breath.
So the moral of the story, figure out what kind of hum you have before diving head first into solutions, lol.
