Losing power

**jnumme** · #1 09-19-2010, 08:07 PM

tonight at rehersal while in the middle of a song my amp seemed to get quieter like someone turned the volume down and i checked everything and all settings were correct for the set up.

now i run a ampeg b4r head in to a svt 6x10 cab I was mono bridge and while jammin it lost some volume and even the guitarist noticed it . can anyone tell me what the heck happened? I had to turn the volume up higher just to cut through the mix .. now this is a 1000watt head and usually has no problem till tonight . Please help!

jelwood · #2 09-19-2010, 08:48 PM

Was it as quiet as it would have been without being bridged? If so you might just have a bad switch.

**jnumme** · #3 09-19-2010, 08:59 PM

yeah i ended up putting it in stereo mode and just went to single amped and it still didnt sound right and changed it mode 3 to mode 4, it seemed to be a little better .. i think i'll bring it in and have the store i bought check it out . its beyond me

dhomer · #4 09-19-2010, 09:03 PM

My guess your problem is decreasing voltage out of the wall. I would think most rehearsal rooms are not wired for large amperage draws. You're running that 1000 watt head probably along with PA and other instrument amps at war volume. This takes a LOT of amperage out of the wall.. The result is lower voltage (could be as low as 90 volts in extreme conditions), and lower volume.

The bad part about this phenomenon is if you try to increase the volume to make up for the lost volume, you wind up overheating the amp, possibly causing output device/speaker damage.

The best solution is to rehearse at lower volume levels...

NateS · #5 09-19-2010, 09:03 PM

curious as to the answer, u have a b4r as well (I love it!) and would like to know for future reference

**jnumme** · #6 09-20-2010, 07:29 AM

thanks fellas ,

BassmanPaul · #7 09-20-2010, 08:44 AM

After the volume loss you set it to stereo - did you check that both power amps were functional? you could have lost one channel.

Paul

**jnumme** · #8 09-21-2010, 06:49 AM

Bass man i will check that out , but i found out yesterday that i was on a ungrounded circuit ... could that be the culprit

BassmanPaul · #9 09-21-2010, 10:21 AM

Quote:

Originally Posted by jnumme

Bass man i will check that out , but i found out yesterday that i was on a ungrounded circuit ... could that be the culprit

No.

Paul

Von Felgenhauer · #10 09-21-2010, 10:29 AM

might be a stupid question, but is your bass active? i know on my 18v pre as soon as the battery starts dieing the volume goes poopy

**jnumme** · #11 09-21-2010, 01:34 PM

yes it is active i use a stingray , but the battery a duracell is not that old .. but friday i try all these things out dont have my rig with me ... i'll check both channels and change batteries

Bassdirty · #12 09-21-2010, 01:42 PM

Quote:

Originally Posted by jnumme

yes it is active i use a stingray , but the battery a duracell is not that old ..

How old is ..."not that old"?

Do you leave your cable plugged into the bass when its not in use?

Sorry...just askin the questions.

BassmanPaul · #13 09-21-2010, 02:26 PM

Quote:

Originally Posted by Bassdirty

How old is ..."not that old"?

Do you leave your cable plugged into the bass when its not in use?

Sorry...just askin the questions.

First thing anyone should do when faced with a problem is change out the battery in an active bass.

Paul

**jnumme** · #14 09-21-2010, 06:51 PM

no i dont leave it plugged in , and i know i should have checked the basses battery first .. i appreciate everyones input i will definately let you guys know when it is solved friday

**jnumme** · #15 09-25-2010, 12:04 PM

put duracell in stingray changed to grounded circuit all is good ... thanks guys for the help