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Just upgraded my Integrated Amp - now here a HUM out of my LUMIN - HELP

I run two systems in my home - System one is in my family room - my old Krell 400 xi died last month. I replaced it with the new Krell Integrated amp the K300i - Everything is better - soundstage is larger - highs are clearer with no harshness, bass is amazing, and midrange vocals are so real Carly Simon vocals bring me to tears! My problem is I now have a very low level pulsating hum between tracks that I cannot eliminated. I have isolated this hum to my LUMIN when i input its feed into the Krell. The low level hum follows the RCA jacks as I move them from inputs S1 to S2 to S3 on the Krell. My DVD / CD player on this system does not have this issue - it is stone silent between tracks. The only ‘odd thing’ about my LUMIN RCA inputs is they are long - 15 feet. I have my LUMIN upstairs feeding my second system via the balanced outputs. This system runs with my older Krell S550i integrated amp. The sound is stone quiet between tracks - no HUM.

i am running the Krell K300i at a volume output of 65 ( volume runs from 0 to 100). I then control my actual volume via my I pad mini via the LUMIN app. My sound is amazing , but this HUM just bothers me. Do I need to ground the LUMIN D1? Both systems get their power via two separate FURMAN ELITE 15 Power Conditioners. I am out of options. Any help would be appreciated
tom8999

Showing 8 responses by tom8999

tom8999 OP
151 posts
 
Miller carbon - thanks for the link - I read it several times. I still have questions. First - I am not an electrician - I am a chemist - so bear with me.

1) why did my old Krell not have this ground hum issue - I ran with this set up for 8 years, and no hum.

2) to correct the hum I need to run a circuit to feed both systems to confirm they both have the same ground? OR

3) I did minimize this issue by running a better RCA interconnect from the LUMIN upstairs to the System downstairs - now using an Anticables 2.2 interconnect with better shielding. The hum is only audible when I crank up the Krell above 70 on it’s volume control.

i can live with this issue now -

4) so grounding the LUMIN chassis will not help?

thanks in advance for the education.

 

tom8999 OP
151 posts
 
Thanks for the additional input - my hum is weird now - it is very faint but it rises and falls when I am not playing music out of the LUMIN, and I have to crank up the Krell and put my ear on the speaker to hear it. So I guess I have interference hum. I am rerouting my cables to get them away from the AC input cables behind all of my equipment. For me the ‘Tell’ here is that I have minimized the HUM over the last days by upgrading my original RCA interconnect to the Anticable 2.2. I just used an extension cord to move my AC input into my Furman to another outlet - trying to find another circuit.  I will let you know how this adventure works out. I guess my new Integrated Amp is ‘sensitive’. I am just glad I upgraded to the new RCA interconnect from Anticables - I am hearing ‘new detail’ in multiple albums via my LUMIN.

again thanks for the education!

tom8999 OP
151 posts
 
ieales - my LUMIN cannot come downstairs as my System 1 does not have Ethernet connection available in the family room. This is why the Lumin is upstairs - I have an Ethernet connection in the wall right behind the stereo system upstairs. Plus I am not an electrician and I do not want to short anything out.
tom8999 OP
151 posts
 
Kudelka8 - please go waste your time elsewhere.
tom8999 OP
151 posts
 
Kudelka8 - my apology - I thought your post was a ‘spoof’.

I have improved my HUM issue by at least 90 % since I set up my new Krell integrated. I will be talking to Krell tomorrow to see if their new amp design has shown this problem.

Happy Listening
tom8999 OP
151 posts
 
Millercarbon- I am making progress - my HUM is getting less and less. All of my AC power cords have been moved away from the RCA interconnects at The back of the integrated amp. My Furman Power Conditioner is not contributing to the hum - I shut it off and just ran the LUMIN, and Integrated Amp but no hum reduction. My new RCA interconnects from Anticables from the LUMIN to the Krell k300i I think are the best investment I have made. I am now convinced I am fighting interference hum.

Thanks for the help.
tom8999 OP
151 posts
 
I wanted to give everyone an update on my situation with my HUM issue. It has now been minimized to a minor issue in my main system.

1) ground loop hum - I ran an extension cord to my upstairs system and put my LUMIN D1 on the same circuit. No improvement in hum reduction.

2) interference hum - I got the most improvement by moving all AC Cords away from my ICs. And I upgraded my 15 foot Audioquest IC to an Anticables 2.2 IC with extra shielding ($350). Dramatic hum reduction, and improvement in music detail from the LUMIN D1 the longer the new IC is in my system. Maxed my volume to 100 on the LUMIN D1 and control volume on the Krell - cannot stay in the room over 40 on the volume out of the preamp ( thanks flashbazbo).

3) DC offset hum - My LUMIN D1 came with a ‘Wall Wart ‘ External DC power supply. Just ordered an SBoost DC power supply from Upscale Audio ($399). - should have it installed this weekend. I am hoping to kill off the last of this HUM with the better DC power supply.

thanks for all the help!!
tom8999 OP
151 posts
 
Final Update - everyone - thanks for the help. My hum is 99.9% gone. The addition of a better DC power supply to the LUMIN D1 hasn’t helped lower the hum to almost nonexistent. And I also need to comment that my streaming has never sounded better than it does now. I credit this improvement to the better IC cables from Anticable and the better DC power supply to my LUMIN D1. I have been using the SBoost MKll for a week now, and the new ICs from Anticable for 3 weeks. I get a better sound stage  and more detail out of. My Maggie 1.7is Thani have ever heard. I am sure the new Krell K300i has a part in this also.

again thank for all your help !!
Happy Listening!
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