Shuttle 9 - Preamp hiss...

Andysalt01 · #1 11-13-2010, 10:01 AM

Hows it going,

Just been doing a bit of home playing, not too loud, and all of a sudden there was a kind of a low background crackle/hiss/weirdness from my cab.

I did a bit of investigation, changed the cab, the speakon, removed the effects from infront, muted the amp, disconnected the lead.....it was still there - even muted!!

Playing with the controls on the front, turning the "Volume" right down on the preamp, it disappears. Does anyone know what this means?

It kinda comes and goes for periods, but I'm a bit concerned about my amp!! thanks for any assists, and I know genz cruise round here so anything from agedhorse and the crew would be great.

Thanks!!

**JxBass** · #2 11-13-2010, 10:13 AM

Could be the tube. A bad or loose tube often causes a popping sound versus a hiss (like mine did), but it could be a sign that it's starting to go or is perhaps defective.

Andysalt01 · #3 11-13-2010, 10:33 AM

I thought the tube might be the reason, but then I thought that was controlled via the "Gain" on the preamp rather than the volume. Turning the gain down doesnt reduce the noise.......

Hopefully not starting to go, as I've only had it for around a year or so, and not been used that heavily at all really.....

agedhorse · #4 11-13-2010, 10:45 AM

Sure sounds like a bad tube. The gain controls the drive to the tube and the volume controls the signal level from the tube.

If you need more help troubleshooting, give Scott a call at the factory, he will walk you through it.

hasbeen · #5 11-13-2010, 03:15 PM

I agree with Andy.....sounds like a tube.

Andysalt01 · #6 11-14-2010, 03:53 AM

Thanks guys, I'll get a new one in and see how thgat fairs! much appreciated, I'll drop a line once its resolved. Other than the tone and amp and looks, best thing is the customer support you guys provide.

thank you

**JxBass** · #7 11-14-2010, 05:17 AM

Mine was simply loose, right out of the box, most likely jarred loose during shipping. I reseated it and it's been perfect since. Yours may have come loose after a year of lugging it around, cab vibration, etc. Reseat it before buying a new tube, although having a spare is never a bad idea.

Andysalt01 · #8 11-14-2010, 05:49 AM

Cool, I'll pop the lid later today and see if it has come loose at all. Havent moved it in a while so unlikely. Then roll on and get a new tube for the front end. Thanks again!

**JxBass** · #9 11-18-2010, 04:45 AM

I'd be curious to know your findings on reseating and/or replacing the tube. The results could be helpful to others who encounter the same symptoms.

Andysalt01 · #10 11-18-2010, 12:34 PM

Ok, so just got a new tube, popped the lid, removed the right hand bracket and.......stuck as to what the next step is!? :/

Has anyone lese retubed the shuttle 9? the board on which the tube is mounted feels flimsy and I'm pretty shy in giving it a good yank as i reckon I'll ende up busting the board its on!! Technique, tips or howe to from this stage would be great!!!

Thanks in anticipation, and I'll be sure to post results.

Thanks again
Andy

Oldtimer · #11 11-18-2010, 12:41 PM

Quote:

Originally Posted by Andysalt01

Ok, so just got a new tube, popped the lid, removed the right hand bracket and.......stuck as to what the next step is!? :/

Has anyone lese retubed the shuttle 9? the board on which the tube is mounted feels flimsy and I'm pretty shy in giving it a good yank as i reckon I'll ende up busting the board its on!! Technique, tips or howe to from this stage would be great!!!

Thanks in anticipation, and I'll be sure to post results.

Thanks again
Andy

Hold the circuit board with one hand, gently pull the tube out while slightly rocking the tube. When installing, line up the gap in the pins with the socket and reverse the procedure.

Andysalt01 · #12 11-18-2010, 03:15 PM

Much obliged, thank you!!

Quote:

Originally Posted by Oldtimer

Hold the circuit board with one hand, gently pull the tube out while slightly rocking the tube. When installing, line up the gap in the pins with the socket and reverse the procedure.

Andysalt01 · #13 11-18-2010, 03:19 PM

It appears it was the tube! No hiss having played the new one for a while, crystal clear, no hiss. I am a little surprised as I thought the average preamp tube lasted for ages, but its academic now as all in order.

Thanks to all the replies and assistance, it is very much appreciated. Still on a learning curve with gear, and guess I will be forever and a day!! All part of the fun of it!

**jlepre** · #14 11-18-2010, 03:42 PM

Is that tube covered under warranty?

Oldtimer · #15 11-18-2010, 04:04 PM

Quote:

Originally Posted by Andysalt01

It appears it was the tube! No hiss having played the new one for a while, crystal clear, no hiss. I am a little surprised as I thought the average preamp tube lasted for ages, but its academic now as all in order.

Thanks to all the replies and assistance, it is very much appreciated. Still on a learning curve with gear, and guess I will be forever and a day!! All part of the fun of it!

Still could have been a loose tube and just needed reseating. A good thing to have a spare anyway. Next time you're in there, try putting the original tube back in just in case it wasn't making good contact. The original tube may still be OK!

**JxBass** · #16 11-18-2010, 04:42 PM

Quote:

Originally Posted by JxBass

Mine was simply loose, right out of the box, most likely jarred loose during shipping. I reseated it and it's been perfect since. Yours may have come loose after a year of lugging it around, cab vibration, etc. Reseat it before buying a new tube, although having a spare is never a bad idea.

Quote:

Originally Posted by Oldtimer

Still could have been a loose tube and just needed reseating. A good thing to have a spare anyway. Next time you're in there, try putting the original tube back in just in case it wasn't making good contact. The original tube may still be OK!

+1.

Pilgrim · #17 11-18-2010, 04:57 PM

Tubes normally last for years to decades, but one can always fail early - or as noted above, it may have been loose.

agedhorse · #18 11-18-2010, 07:45 PM

Tubes in general are lower reliability than transistors and because they are electromechanical, noises and variable performance is sadly not uncommon. It's not an amp problem, it's a tube problem and all manufacturers struggle (or should struggle) to obtain the highest possible reliability through forgiving designs, thorough testing and good tube manufacturer relations. Even then, some tubes will fail.

FarkusSWR · #19 11-18-2010, 07:56 PM

Is it possible that the tube could be responsible for volume fluctuation? I have had a intermittent problem with that the last couple gigs.

agedhorse · #20 11-18-2010, 11:03 PM

Quote:

Originally Posted by FarkusSWR

Is it possible that the tube could be responsible for volume fluctuation? I have had a intermittent problem with that the last couple gigs.

Yeah, it's certainly possible.