2. amps-preamps
  3. 147116-79353

Phono preamp make crackling noise

Looking for advise from any of the audio Gurus.

My set up consist of Unison research Unico pre connected to Auris audio Forte 150 mono blocks, my speaker are Focal Sopra N3. I also have BLUESOUND NODE 2 (Dac/ streamer).
I do not have any issue with noise when I play music through my BLUSESOUND NODE either Tidal or Spotify..
I recently purchased Unison Research Simply phono Tube Phono amp with separate power unit. As soon as I connect the ’Simply phono’ to pre amp and set to appropriate input I get crazy cracking noise on my speakers. It is not a ’Hum’ like you hear with ground issue. I don’t even need to switch on the Turntable. It overpowers the sound of my music.
I am trying to eliminate each piece of my equipment. I even took my Phono preamp and the preamp to a Hifi audio store . we connected my equipment at the store and amazingly it played without any noise. I have changed interconnects / power cables still it is noisy . Looks like the issue is in the wall electrical. I just moved to a new house.
Any help will be appreciated. I even tried to move my NAS drive away. Just driving me nuts!!!!
128x128vishu
vishu's avatar
vishu OP
28 posts
 
millercarbon
You are absolutely right about the gain. I don't understand why a phono stage that cost $2500 CAD have fixed gain of 52db? I was keen on tube phonos staged that's why I bought the 'Simply Phono',otherwise solid state Gold note PH10 is an amazing phono stage , where you can adjust the gain.  Ph10 did not crete any noise in my system. I tried couple of phono player, both were noisy. My issue is without even turning on the phono player, by just turning on the phono preamp, connected to my preamp I hear this very unpleasant  noise. As soon as I unplug the RCA to pre amp or turning off the phono stage the noise disappeares. I also found out any wifi extender  plugged into wall socket close to my equipment induces considerable noise.
kalali's avatar
kalali
1,977 posts
 
What's your cartridge's voltage, is it MC or MM? The crackling noise is usually from the tubes especially if they're running through a very high gain stage like 52 dB. Depending on the tube type you may be able to try a lower gain/noise version, e.g., 12AU7 vs. 12AX7, etc. 
vishu's avatar
vishu OP
28 posts
 
The factory tube is  four ECC83 Valve – also known as the 12AX7.
I tested it on MM cartridge. 
The store is figuring it to be issue with my wall power and wifi adapters noise being picked up by my phono stage and amplifying  it many times.
I have an electrician coming today to check it out. 


cytocycle
1,043 posts
 
is the turntable grounded to the phonostage? and have you also tried adding a ground from phonostage to the preamp via a screw on the chassis if it doesn't have a grounding post.  Most likely a grounding issue.
jayctoy's avatar
jayctoy
4,072 posts
 
Cytocycle agree that’s what happen to me, I have to buy the Audioquest ground wire...from tt to preamp...
More to discover