2. amps-preamps
  3. 1203818882

Fuzzy Sound in my Audio Research SP16 Phonostage

over the last week or so i have been having trouble with the phono stage in my Audio Research SP16 pre amp. for the first 15 or 20 minutes of listening to vinyl the sound quality is all fuzzy and staticy - like poor reception on a radio tuner. you can hear the music, but it is buried beneath a layer of distortion. over time it gradually goes way - after 5 minutes or so it starts to diminish, and it is generally completely gone in 15 minutes or so. it has me concerned.
this only happens on the phono stage - not on any other input. it does not matter how long i let the pre amp warm up either. if i turn on the pre amp and listen to vinyl right away, or if i listen to CDs for an hour and then switch to vinyl i still get the same fuzz.

by the way, my turntable is a rega P5 with an Exact II cartridge. as far as i can tell there does not seem to by anything wrong with the turntable. i have been using this turntable and cartridge with the SP16 for several months now, but this problem has only presented itself in the last week or so.

my guess is that i have a bad tube in the pre amp, but i really don't know for sure. anyone have advice for me?
skuras
skuras OP
55 posts
 
the fuzziness is in both channels.

can i retube the pre amp myself? is it just a matter of popping the top on the pre amp and plugging in new tubes?
dopogue
1,773 posts
 
We need an AR expert here to confirm or deny that one preamp tube could affect both channels but yes, retubing should be straightforward.
swampwalker's avatar
swampwalker
5,138 posts
 
I'm no expert, but IIRC the phono stage in my SP-p used on half of a 6DJ8 for each channel of the phono stage.
skuras OP
55 posts
 
i have not heard that fuzzy sound for a couple weeks now. it has completely gone away.

could it possibly have been caused by static electricity?at the time the problem first presented itself it was VERY cold and VERY dry here in michigan. now that the temperature is more moderate the problem is gone. right around the same time i was getting a pretty good shock every time i touched something metal in the house, due to static from the carpet.
davemitchell
253 posts
 
Sounds like a static discharge might have zapped one of the microprocessors in your unit. My normal recommendation would be to disconnect and unplug the unit for a few minutes to reset everything and then plug it back in.

It sounds like yours is already working again so you should be fine. If it happens again, try to unplug. If the problem keeps coming back, it may need to go to ARC for service.

I'm an ARC dealer.
More to discover