[Povell42]

I will be taking my DAC/AMP home with me soon and will set it up there and see if it still does it. I moved the AMP off of the metal surface and placed it on the desk at work and it still hums after letting sit, even with the amp in off mode. I have the Mimby sitting on top of the AMP and I noticed when I take the Mimby off of the AMP the noise somewhat disappears. I have the Mimby hooked up to the 789 via Monoprice RCA to 3 prong balanced cables. I have the LCD3 pluged into the balanced output of the 789

I have owned the LCD3 for about 2 years and have never had this happen before, anywhere. I am starting to wonder if I have a bad ground on the AMP. Before I got the 769, my main setup was Mimby to Aune X7s to LCD3. With that setup in the same location I never notice this humming, so I don't think it is the LCD3's at fault.

UPDATE: I am thinking it has something to do with the "Auto Off" mode. I have not been able to produce the hum when I turn the AMP to "BYPASS" mode... which is basically off.

UPDATE #2: I heard the hum faintly with the 789 in "Bypass" mode. DANG!

 

[BrotherKathos]

I will be taking my DAC/AMP home with me soon and will set it up there and see if it still does it. I moved the AMP off of the metal surface and placed it on the desk at work and it still hums after letting sit, even with the amp in off mode. I have the Mimby sitting on top of the AMP and I noticed when I take the Mimby off of the AMP the noise somewhat disappears. I have the Mimby hooked up to the 789 via Monoprice RCA to 3 prong balanced cables. I have the LCD3 pluged into the balanced output of the 789

I have owned the LCD3 for about 2 years and have never had this happen before, anywhere. I am starting to wonder if I have a bad ground on the AMP. Before I got the 769, my main setup was Mimby to Aune X7s to LCD3. With that setup in the same location I never notice this humming, so I don't think it is the LCD3's at fault.

UPDATE: I am thinking it has something to do with the "Auto Off" mode. I have not been able to produce the hum when I turn the AMP to "BYPASS" mode... which is basically off.

UPDATE #2: I heard the hum faintly with even with the 789 in "Bypass" mode. DANG!

I switched my headphones to the hd6xx and dac to topping d50 with eitr on my bedroom setup with thx and now hum is gone. The lcd2c is at my other rig with mimbt eitr and loki. the stack is next to amp and not on top anymore and hum is gone there as well so far. I think its a combo of amp dac and headphones, ut headphone is the main culprit imo. otherwise how would having my ipad in my hand and the headphone on my head cause a ground noise. i can literally play hum tunes as i grab and let go of the ipad if it’s charging. That is only possible if the headphone is conducting electricity through my body.

 

[BrotherKathos]

its like the drivers of the headphone become connected to each other through your head due to passing current through your brain. SCARY

 

[Povell42]

Just tested for both of the issues at home now, and neither are present. NO noise after pausing music and then the volume all the way up, and NO noise after letting it sit for like 20 minutes. So weird!

Maybe its static electricity, or dirty power at work? I am stumped. I have never experienced that at work before.

I am using digital coaxial cable form my motherboard into the Mimby at home.. and was using USB to a creative sound external sound card that has a digital optical output to the Mimby. Either way, I am confused. Hehe

 

[omniweltall]

You should contact massdrop and get a replacement, mate.

 

[Voxata]

I've had absolutely no issues with my THX789. It runs cool, sounds good. Performance is exemplary.

 

[alpovs]

I have the Mimby hooked up to the 789 via Monoprice RCA to 3 prong balanced cables.

I think this is the key! Connect either RCA to RCA or balanced to balanced. RCA to balanced is a misnomer. This cable is actually balanced to RCA and should not be used in reverse. Try RCA to RCA and see if your problems are gone.

 

[Povell42]

I think this is the key! Connect either RCA to RCA or balanced to balanced. RCA to balanced is a misnomer. This cable is actually balanced to RCA and should not be used in reverse. Try RCA to RCA and see if your problems are gone.

Good suggestion, although I have not been able to duplicate the issues when I have it set up in my home office. Must be something weird about my work office.

 

[bequietjk]

I used fleetwood mac as a reference due to many recordings being way out of control in how they are mixed (loudness wars). steely dan, pink floyd also seem to be recorded very well. so my definition of loud enough is that fleetwood mac isnt quite loud enough with volume halfway on hd 600...oh, should mention I was using tidal...maybe my flacs on hd louder...Im just thinking if I had 600 ohm headphones no way would this amp cut it...just my opinion. lots of music out there I would have to turn down alot.

Any change in audio hardware I go directly to 96khz FLAC Fleetwood Mac Rumors then jump to Steely Dan, eventually making my way to some more electronic music. But the first track I always play is 'Dreams' off of Rumors. Get's me every time.

 

[Marlowe]

The first thing I always play when I get new headphones or other new gear is Behind Blue Eyes from The Who's Who's Next, my favorite album of all time since I bought it on vinyl in 1971. Nothing better to judge new gear than John Entwistle's deep and melodic bass.

 

[BrotherKathos]

Dark Side of the Moon from Floyd for me on a new system.

 

[MacMan31]

Dark Side of the Moon from Floyd for me on a new system.

Good choice.

I finally got notice from Periapt that my XLR cable for my HD6XX is on its way. Can’t wait to try it out.

 

[BrotherKathos]

Good choice.

I finally got notice from Periapt that my XLR cable for my HD6XX is on its way. Can’t wait to try it out.

Nice! I got a balanced one from massdrop that I've been pleased with. I don't get past 12:00 on low with the hd6xx with the balanced output. Makes the hd6xx very nice imo with the thx and topping D50 I'm using in the chain.

 

[Zachik]

Dark Side of the Moon from Floyd for me on a new system.

Dire Straits for me... Sultans of swing, Money for nothing, Brothers in arms.

 

[ReAlien]

My audio gear testing playlist:

Yes - Roundabout
Pink Floyd - Us and Them
Dire Straits - The Man's Too Strong
Elvis - Fever
Led Zeppelin - You Shook Me
Diamanda Galas - Artemis
Slayer - Live Undead
David Bowie - Five Years
Doors - L.A. Woman
Deep Purple - Soldier of Fortune
Frank Black and the Catholics - Stupid Me
Beck - Paper Tiger
Mimicking Birds - Pixels / Subsonic Words

P.S. Still waiting for my THX to arrive to test it with it, in a week time I will do that.)))