2. amps-preamps
  3. 165892-160324

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
filipedine
36 posts
 
Hi, 
I've had a similar issue,  In my case it was an AC issue where other devices where sending hight frequency. to solve it got one of does iFI AC Purifier.
Hope this helps
Fil
rmdmoore
163 posts
 
I just had a very similar issue and it had to do with the step up transformer in my phono stage picking up noise generated by my Google home wifi router. A good way to check if it's that kind of interference is to literally pick up the unit while it's on and see if the sound changes. If it does, it's something fairly nearby. If you're wifi router is close I'd move that and see if it helps.


musicfan2349's avatar
musicfan2349
236 posts
 
I recently had an experience where I had a wifi router too close to my system. Everything was okay (CD and streamer) but when I turned on my phono pre-preamp, Conrad-Johnson Premier 6, it would pick up RFI from the router that sounded like the alien transmissions in the movie Independence Day. Turning the router on and off confirmed the problem. I wound up buying a long Cat8 cable and moving the router to the other side of the living room.

In your case however it sounds like you’ve turned off all close sources of RFI that you can with little to no effect. To key clue to me was that you heard the same sound at the store... IMHO I would return the Sutherland and try another/different step up device. It sounds like it’s simply too sensitive to RFI in your environment. (Frankly I’m surprised they let you walk out with it if it was acting up at the store.) Let us know how it goes.
Happy listening.

wally828 OP
9 posts
 
Hi All,

Just catching up to all these messages. Much thanks for everyone's input. 

@oldhvymec the preamp doesn't have a ground switch, just the nut for the ground wire. the TT itself doesn't have an external ground. Apparently the way Rega makes their turntables, they're grounded internally so I don't really have options there. That being said, this isn't really a ground "hum" as I've heard it being described. 

@jdane that's what i plan on doing. Anyone have any reccos? 

@terry9 I have a good set of interconnects that go from the preamp to the receiver, shielded and all. The interconnects coming from the rega are integrated so I can't really mess with those. 

@filipedine that would just eliminate noise coming from the AC source but not whatever is going on inside the preamp if it's picking up RF though I'd imagine? 

@rmdmoore I did that and the noise did change a bit! I actually turned off everything in my home that emits that type of frequency and still heard the noise - phones, tv, tablets, router...as mentioned previously, i live in Brooklyn and my setup is near a big window so I don't think I can hide from RF, unfortunately.

@musicfan2349 that's exactly how i'd describe the sound, lol! TBH, the store is really push about letting me return things which I find very annoying. They said they had to call ron sutherland and ask him if he could take the product back. They really don't allow returns, so I think I need to find a shop that does. 

I just read about this preamp last night, https://www.analogplanet.com/content/qhw-audio%E2%80%99s-surprising-%E2%80%9C-vinyl%E2%80%9D-mmmc-phono-preamp which sounds good, I just don't know what to look for/what not to look for that would point to a preamp possibly picking up RF. If any one has any suggestions, I'd love to hear?

On another note, I'm new to this board and maybe making my replies more consolidated than I'm able to. When I try to @ people, only a few members show up in the drop down list? Is there a way to reply back to specific people so they know I've seen/appreciate their response and am replying back to them? 

terry9
2,333 posts
 
RF can appear in several ways. The most obvious is when you turn the volume all the way up with no program material, and hear "Take Five" playing in the background. Another way is just a small loss of detail in the music you are playing. Or anything in between. Even, perhaps, the problem that you are experiencing.

Note that not all cable shielding is created equal. Indeed, I have used cabling with shields that are little better than nothing at all (but not for long!).
More to discover