2. amps-preamps
  3. 1250637079

Vibrating Woofer, old tubes?

I have a dual mono tubed phono section that even has an active tube line input for a cd player. Now, I have a little problem with it, and I am not sure what the cause is.

When I open the volume wide open it causes my speakers to vibrate and gives and it hums in strange way. The weird thing: It goes away after I let the unit heat up for a couple of hours, usually. After using it for a couple of hours I can open the volume pot wide open, I mean wide open and it is as quite as a Church.

Is the thing scrap metal or is it something easy to fix?

Can it just be the tubes needing to be replaced?

I am a little freaked out about, becuase I really do love the item and have no desire to purchase another tube phono section or even tube pre at all; though I would like to be able to use it without damaging my loudspeakers. I will be getting a new pair any day now and I am a little worried. Please help me out guys, thanks a million.
dfelkai
dfelkai OP
89 posts
 
LOL, very true Rodman.

BTW, what was it like playing for the Bulls?
ghosthouse's avatar
ghosthouse
4,306 posts
 
No! didn't he play for the Detroit Pistons??!!

Gosh - now I've been taking to heart audio advice from that person...mmm...got to think about this one. :-)
dfelkai OP
89 posts
 
how much do you think I should be paying for the labour? I talked to a local tube expert today, he will give me an estimate a couple of days after I drop off the unit. I don't want to overpay, help me not get ripped off. Thanks again.
atmasphere's avatar
atmasphere
11,784 posts
 
Dfelkai, most shops in the US will charge about $75-$80.00 per hour. That allows them to pay the technician and their overhead. Filter caps do not take a long time to change, and this is entirely off the top of my head, so unless there is something really unusual about this preamp I would guess that 2 hours is all that is needed.

Without even seeing the unit, that's the best I can come up with- diagnosing at a distance has its problems :)
swampwalker's avatar
swampwalker
5,138 posts
 
What you may find is a "bench charge" or a diagnostic charge. Maybe $30-50 to be applied against repair if you go ahead. some shops will have a 1 or 2 hr minimum. Lots of variability in terms of minimum charges, etc. If $75 or $80 seems high, my plumber has a $100 minimum! 'Course his family is the biggest real estate holder in the most exclusive suburb in my region!!!
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