TRL Dude or Joule 150 MKII for Major Pre Upgrade

Mine preamp's chassis is indeed grounded to the middle pin of the iec. Again, the buzz comes when the preamp is off and unplugged even. I have an amp issue. I called Aesthetix today and they gave me some other things to measure on the amp.

I will report back on how this ends up so all can learn. Thanks to all for the help.

Okay, I read through the whole threads and come up with another theory and idea to try. I simply cannot stand a fellow Dude owner not happy with his setup. ;-)

I still think it is a grounding issue. If I understand it correctly, it did not hum with the previous set of speakers which are electrostatics. My theory is that the set of electrostatics provided proper grounding through their AC plugs.

So, Bill, can you try the following and see if it fixes the hum? The idea is to provide grounding at the source. So find any of your source equipment that has the signal ground wired to the ground pin of the AC plug. I don't know what source equipment you have. But you can measure the source's output RCA ground and the the ground pin of the AC plug. If it reads close to zero ohm (meaning there is a connection), then the signal is grounded to the AC line. You can use that equipment as the source.

Then connect the source to the Dude and select the right input. Connect the Dude to the amp. Turn them on and see (or hear) if you still get a hum.

Please let us know. Thanks.

Bill, in your earlier post today, you said that the chassis was not wired to anything, which was similar to my experience. Then you said it in your most recent post that the chassis was wired to the middle pin of the IEC. So I am a bit confused. Can you use your ohm meter to measure the chassis and the ground pin of the IEC socket?

Did you send your Dude back for re-work? I got my Dude after reading your review a few years back. Being an engineer, I opened it up to review its design as soon as I received it. I found that the chassis was NOT wired to the AC ground. I sent it back to Paul and specifically asked him to do so later on.

I still think you should try my latest suggestion: find a source equipment that has its signal ground wired to the AC ground pin. Then see if it still hums...

I measured the Atlas amp again. It turns out if I touch the back steel plate I get no ohm reading. However when I touch a screw on the back plate with the center power cord ground pin on the iec I get a 14 ohm reading.

I learned this from calling Aesthetix. They tell me the amp is fine and I have some sort of unique room/house situation. Seems they will not be able to help me anymore and suggested I try a balanced preamp. Well, my amp has RCA inputs for a reason and I need to use them!

I am starting to doubt I will ever get an answer.

Vett93, the speakers buzz with my cd player unplugged and ic's also taken out that go to the cd player. So the source it not at all in play here.

I need to bring the amp to another home and system and see what happens.

Granny,

I don't think my explanation is clear to you. My point is that the signal ground has to be grounded at one location for the entire system. Otherwise, the whole thing is floating. It seemed to me that your electrostatic speakers provided a grounding point. You lost the grounding point by switching to a set of passive speakers.

If you still use the same CD player as the one you used when we talked last time (a Marantz, I think), it does not provide a grounding point. If you look at the IEC socket of a Marantz CD player, there is no ground pin there.

To test my method, you will need to find a CD player that uses the AC ground pin, and plug in AC power cord to the wall and use the interconnect too. This is so that the CD player can provide a grounding point for you. I don't think you followed my explanation.