2. amps-preamps
  3. 161387-96791

Constant noisy tubes maybe go solid state?

I have a Quicksilver Line Stage Preamp (12AT7) mated to an Odyssey Khartago Stereo. Overall I like it. Way too much gain but I digress. Weeks after receiving it I rolled in a few different tubes, kinda fun to color the sound signature. I liked rhe RXA black plates I got and those stuck around for more than a year. They started going microphonic and making noises so I ordered another pair (noisy) then another different vendor (blasts of white noise) and another set that arrived today (one is noisy as holy hell and one seems fine).

So where does one order preamp quality tunes that are quiet? Is there something I’m not requesting when ordering? Maybe dump
snd go solid state? I’m trying to be humorous because I’m pissed. Ha.
gochurchgo
decooney
1,906 posts
 
One example, having a humming (unclean) coax cable from a cable TV company plugged into nearby boxes sharing similar or conjoined AC outlets on the same circuit back to the junction box can do this too.  Amps with big transformers can simply amplify this too, right to your speakers. Bzzzzzzzzzz. Many years ago finally caved and went to a dedicated AC circuit and power-conditioning station. Much better.  
aj523
360 posts
 


@sokogear
Thx dude! My entire system - phonostage, preamp, amp, are tubes and I have an Audioquest Niagara 5000. I think you’re right though, my home theater is solid state and dead quiet. Idk worth the compromise for me and it’s not audible until the volume is at least half way turned up with my ear pressed against the speaker. At a couple of feet away no level is audible but of course I’m 53. Lol.  
leemaze
329 posts
 
I sent back my crazy noisy RCA blackplates to Brent Jesse and spent 4x the money for Mazda 12AU7s pre-tested for noise and microphonics. These are better - actually listenable - but there’s a weird high pitched whine every so often and I can still clearly hear hiss from the listening position in quiet passages of music. I like the 3D effect but find myself straining to hear the music at my normal listening volumes (~60dB). This is after 72hrs of burn-in. 
Amp is Rogue Sphinx v2. Speakers are Wharfedale diamond 10.7. 
Am I missing something? Is this as quiet as it gets?

Thanks!
gochurchgo OP
892 posts
 
@leemaze I had that issue too when the RCA's were on their last legs. Intermittent super high pitch whine. Seems to come on more often the longer they were burning in a single session. Might be tubes going bad.
slaw's avatar
slaw
20,484 posts
 
Why not talk to Mike Sanders?
More to discover