2. amps-preamps
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Preamp making loud pitched morse code sound

I just hooked up the final parts of my system this weekend and am getting this pretty awful noise that I can't figure out the source of. I would be GREATLY appreciative if someone were able to help me out. I'm very new to the hifi world so needless to say, it's pretty frustrating to finally have everything hooked up and get an awful noise when I was expecting smooth sailing (silly me?). 

I have a cambridge cxa81 integrated amp and kef ls50 meta speakers that I've had for a few weeks now listening to digital music through Tidal until my turntable/preamp arrived and it's been a great experience. I finally picked up my turntable/cartridge/preamp on Tuesday - rega p6 turntable, hana ml cartridge and sutherland kc vibe phono at stereo exchange in nyc. the sales rep was very nice and put everything together for me in the store to make sure things worked properly before I left. When he hooked up my turntable/preamp to a receiver/speakers in store, it sounded great but it was picking up some radio frequency which we found very strange. We thought maybe it was an issue with where we were and that the issue would go away when I hooked it up at home.

https://www.icloud.com/photos/#0sPNXSiNWROvNUUnRmh1YSglg here is a video of the issue i'm experiencing. I've been searching online since this afternoon and can't really find an answer. Everyone I hear talking about the kc vibe raves about how quiet it is which is obviously the opposite of what I'm experiencing. As soon as I turn up the volume to around 10-11 o'clock, you start to hear it at a decent level, then it gets louder as I turn the volume up. It's subdued when I actually play music, but you can still kind of hear it in the background if you try, or put your ear closer to the speaker. 

What I've tried from the time I've spent online looking for an answer: turned phone on airplane mode and turned off router (not sure how much that'll since I live in Brooklyn where RF/EMF is flying around everywhere), plugged the preamp into a different power source then everything else is plugged into, moved the preamp further away from the system setup, unplugged my tv...I think that's it so far. 

I also plugged my previous turntable, audio-technica lp120 to the kc vibe and still hear that sound. When I plug the lp120 straight to the receiver and use the onboard preamp, I don't hear anything. 

There's absolutely no noise when I switch the input to listen to music digitally, just when i turn the preamp on. 

Any suggestions? 
wally828
oldhvymec
5,101 posts
 
OP how’s that cable routing? Did you just plug drop and listen?

Can you move cables with the volume up and hear a yo yo effect?

It’s routing.. Do a little cable art and don’t let anything touch, cross at 90s and still keep space between cables.. BE very mindfull of PC and Speaker ICs, that can get real noisy..

Routers or computers, unplug them.. Turn them off and unplug the PS to them...Noisy...

MATCH volumes between sources correctly...  All I got for no cost.. 

Happy hunting...
wally828 OP
9 posts
 
Sorry, but what does OP mean? I have the integrated interconnects from the turntable to the IN connection on the preamp and interconnects going out to the receiver.

Messing around with the cables doesn't seem to affect the problem. I did the cable art and it didn't help. 
ghosthouse's avatar
ghosthouse
4,335 posts
 
Is there noise when you plug the Rega TT directly into your (Cambridge CX81?) receiver?

I’m guessing the Sutherland preamp is picking up some kind of digital interference.

Tried calling Sutherland for tech support?

If the store is not too far, consider taking your receiver, turntable and the phono-preamp back to the store. See if there’s noise there. If yes, try another Sutherland pre-amp in the store.  Maybe your phono pre is defective?

OP = original poster (i.e., YOU).
millercarbon's avatar
millercarbon
12,531 posts
 
I listened to the noise, thanks for sending the file. You are right, Morse Code: same thing over and over again: LET ME OUT... LET ME OUT....
millercarbon's avatar
millercarbon
12,531 posts
 
Sorry, couldn't resist. Besides, you know the answer. You heard it in the store: RFI. The phono stage is picking up radio frequency noise. It was different in the store because different RFI environment, also different cable routing. Play with the phono lead and RCA connectors, and if you hear the noise change this is confirmation. 

Your choices are fuss around until you track down the solution, or take the rig back and say what it did here in the store it is doing at home, let's try something else. 

If you want to try and track it down, first clean all contacts with alcohol and a clean cloth. Then try moving the phono lead. Every wire is an antenna, they are all chock full of radio frequency noise, it is just random chance that some of it gets "tuned" out to what you are hearing. All the rest of the time that same noise is there, just not in a form or at a frequency you hear well enough to recognize as noise. But it is there. Trust me. One of the many reasons some interconnects and speaker cables and power cords sound better than others is their ability to reject RFI. 

Wait I just noticed you are in Brooklyn. I would remove the cover and check. Just in case there is someone living in there. 
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