museummouth Posted September 11, 2014 Share Posted September 11, 2014 So my set up is: Pro-ject RPM 1.3 Pro-ject Phono Box MM Audioengine A2s I'm getting hum on mid to high volumes through the speakers only when something is inputing into them. With the turntable off and only the preamp connected I still get hum so it can't be the turntable. I've switched preamps too and still the same. It's only noticeable between tracks or at the beginning of a LP. Quote Link to comment Share on other sites More sharing options...
dethrock Posted September 11, 2014 Share Posted September 11, 2014 So do you get hum at mid to high volumes, when the turntable is off, or between tracks and at the beginning of an LP? Quote Link to comment Share on other sites More sharing options...
museummouth Posted September 11, 2014 Author Share Posted September 11, 2014 So do you get hum at mid to high volumes, when the turntable is off, or between tracks and at the beginning of an LP? Always on mid to high whether the TT Is connected or not. Quote Link to comment Share on other sites More sharing options...
Tardcore Posted September 11, 2014 Share Posted September 11, 2014 What is the ground cable connected to? Quote Link to comment Share on other sites More sharing options...
museummouth Posted September 11, 2014 Author Share Posted September 11, 2014 Turntable ground is connected to the preamp ground Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 11, 2014 Share Posted September 11, 2014 I've had the same issue with the A2s... Switched preamps, and just got another turntable, but its still there... My ground wire is connected to the back of the pre amp and like the OP says, the hum is there whether the turntable is on or off Quote Link to comment Share on other sites More sharing options...
circuit bored records Posted September 11, 2014 Share Posted September 11, 2014 Are you guys using any type of power conditioner or surge protector? Quote Link to comment Share on other sites More sharing options...
museummouth Posted September 11, 2014 Author Share Posted September 11, 2014 Are you guys using any type of power conditioner or surge protector? Yeah I've got all the components plugged into one strip. Tried moving each one to just the wall and nothing helped. Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 11, 2014 Share Posted September 11, 2014 Using a surge protector here... 4000 plus joules Quote Link to comment Share on other sites More sharing options...
xxmartinxx Posted September 11, 2014 Share Posted September 11, 2014 You probably have a ground loop. I assume that your powered speakers and your phono preamp have wall wart power supplies. Take the one of them and turn it 180 degress, so it's facing the other way in the outlet. That might fix your issue. Quote Link to comment Share on other sites More sharing options...
allenh Posted September 11, 2014 Share Posted September 11, 2014 It can be one of the down sides of powered speakers. putting the power supply and the stuff that makes and sends out the noise in the same box makes it pretty difficult to stop this sort of noise breakthrough. If it's not a ground loop as xxmartinxx suggests there are things you can do but I suspect it's the power supply inside the speakers you need to suppress. I suspect it's more of a problem for you guys in the US as you don't tie one side of your mains down to ground as we do here. Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 12, 2014 Share Posted September 12, 2014 The speakers have a power brick, actually. I kinda gave up on getting rid of the hum a while ago, but I've been trying again since this topic started. Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 12, 2014 Share Posted September 12, 2014 Putting a hum eliminator in the pathway was my best shot... I give up. I just want a nice pair of powered speakers. Bought mine used from Craigslist, and kept them under the assumption I'd be able to fix the hum problem later. Quote Link to comment Share on other sites More sharing options...
xxmartinxx Posted September 12, 2014 Share Posted September 12, 2014 Putting a hum eliminator in the pathway was my best shot... I give up. I just want a nice pair of powered speakers. Bought mine used from Craigslist, and kept them under the assumption I'd be able to fix the hum problem later. You bought them with the hum issue? Have you done what I suggested and invert the plug? Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 12, 2014 Share Posted September 12, 2014 When I tested em, I used the aux input. When I use that, there is no hum. Took em' home plugged in the turntable using the RCA inputs and bam hum. I've had two preamps and two turntables since. Yeah I tried what you suggested but no luck. Quote Link to comment Share on other sites More sharing options...
xxmartinxx Posted September 12, 2014 Share Posted September 12, 2014 Have you tried different RCA cables? Have you contacted the manufacturer of the powered speakers? Have you thought about investing in some real audio equipment? Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 12, 2014 Share Posted September 12, 2014 Tried a dozen RCA cables... Haven't tried the manufacturer thing... And nice shot with the "real audio equipment" comment. haha I'm slightly insulted and kind of nodding yes in approval. As for buying more audio equipment, don't think I ever will due to space and especially money. Quote Link to comment Share on other sites More sharing options...
xxmartinxx Posted September 12, 2014 Share Posted September 12, 2014 Tried a dozen RCA cables... Haven't tried the manufacturer thing... And nice shot with the "real audio equipment" comment. haha I'm slightly insulted and kind of nodding yes in approval. As for buying more audio equipment, don't think I ever will due to space and especially money. That was too tempting to resist, however, to a certain degree with audio, you get what you pay for. Sometimes you pay for poorly designed, poorly shielded headaches. Quote Link to comment Share on other sites More sharing options...
allenh Posted September 13, 2014 Share Posted September 13, 2014 One possibility, when you say you use the aux input no hum but RCA you get hum do you mean you are using a 3.5mm jack plug? If so then you have an audio ground missing on the RCA side somewhere as they are a common pin in the 3.5mm plug. And another thought, not knowing these is the power brick giving out AC or DC? if it's DC then getting a higher current output/better quality one could help. If it's AC the problem is either as xxmartinxx says a ground loop or the rectification/regulation inside the psu section in the speakers, in which case if it's not a ground loop it's going to be harder to get rid of. Try swapping the plug around to see if it is ground loop, it's worth a go, also cable routing as well as the cables could be acting as an antenna and picking up a hum but I am clutching at straws at this point. To be honest it's most likely somewhere in the Power supply be it the brick or inside the speakers. Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 22, 2014 Share Posted September 22, 2014 Yeah... im done with switching around plugs. Ordered a new power brick. I'll see how that goes. Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted September 24, 2014 Share Posted September 24, 2014 Well... the new power brick didn't work... oh well... Quote Link to comment Share on other sites More sharing options...
allenh Posted September 26, 2014 Share Posted September 26, 2014 It's in the speakers then, time for an upgrade then? Quote Link to comment Share on other sites More sharing options...
solidusjerry91 Posted October 27, 2014 Share Posted October 27, 2014 It's in the speakers then, time for an upgrade then? Seems like it. I will probably move on to some passive speakers. Quote Link to comment Share on other sites More sharing options...
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