BA-115 - quiet with SX Jag bass

progrmr · #1 06-18-2011, 10:07 AM

So I just bought this Ampeg BA-115 used and got it home. I notice there's a LOT of hiss. After researching the site here, I see that's a common problem. No biggie, I'll take care of the tweeter at some point.

But here's the real thing...When I crank the volume and master to 10, the amp is not very loud unless I boost the eq's..then the windows will start to shake.

Why is this? I'd think that having the eq's at 12 o'clock and having the volume and the master at 10 the thing should be loud as hell!

I'm thinking a couple things:

1. The guitar sucks - maybe I'm finally seeing the downside to buying a cheap bass. Seeing as I'm getting back into bass, it's the only one I have right now and I don't know anyone else that plays so no other test model. I could buy another bass.

2. There could be something wrong with the amp. I'm not sure about that, it seems to work fine other than being a bit quiet for my expectations.

Any ideas??

JimmyM · #2 06-18-2011, 11:22 AM

Hard to tell without being there. It's not the loudest amp ever made but it should get some ass behind it.

BassmanPaul · #3 06-18-2011, 11:48 AM

Take your bass to the store and try it through the same model amp there. If the results are similar then likely the amp is OK. Then try one of the stores basses through the same amp and see what happens.

mikezimmerman · #4 06-18-2011, 12:01 PM

Which input are you plugging into? Even with an active bass, I'd always recommend using the 0dB input unless you were getting distortion. Also, how do you have the 5-way "Style" control set? It does give a nice selection of preset EQ curves, but some of them sound cut through better than others. Last, have you plugged this bass into other amps, to know how hot the output is and how loud it is going though something else?

As JimmyM said, the BA115 isn't the loudest amp in the world--I wouldn't do a rock gig with it--but I use one pretty regularly at church and it should easily get plenty loud for home use.

Mike

progrmr · #5 06-18-2011, 12:32 PM

Actually I think I misunderstood how this amp works...check this out -

So with the Volume and Master at 10, the signal is as big as it can get on all frequencies before it hits the treble, mid, and bass adjustments. Those dials are 0-10 - so I think what's happening is that when I set these 3 to 12 o'clock, that's actually cutting the full signal down to 1/2 on all 3 frequencies.

So really, in order to get full power on this amp you have to set the volume and master to 10, then each of the 3 other controls to 10 so that the signal coming from the master volume arrives at the other end of the chain undisturbed.

I guess with this amp you get your settings where you like 'em as high as you can on the treble, mid, bass adjusters then use the volume and master volume to adjust the size of the signal before it hits that part of amp.

sound plausible...??

BassmanPaul · #6 06-18-2011, 01:01 PM

mikezimmerman · #7 06-18-2011, 01:16 PM

Quote:

Originally Posted by BassmanPaul

No.

I agree, as someone who uses one of these amps on a regular basis.

EQ settings affect the gain somewhat on ANY amp. It doesn't make any difference that the knobs are numbered from 0-10. Heck, if you're going by the numbering, the "flat" setting would be with all the EQ knobs at 0!

Have a look at the manual at http://www.ampeg.com/pdf/BA-115.PDF. You can clearly see what the frequency centers are for each of the controls, and they do not cover the entire frequency spectrum.

progrmr · #8 06-18-2011, 01:39 PM

My amp is a little different than the PDF shows but guessing it's just terminology - I have no gain, it's Volume, and my mid is just Mid, not Ultra mid.

In looking at the block diagram, I think I'm pretty close. 0db in to the gain, then to the style switch which cuts/boosts certain frequencies in the signal, then to the Treble, Mid, and Bass.

Now let's just take on the first one - the treble. The diagram shows a resistance branch for the treble frequency. Setting the Treble knob on the amp to 10 would send the signal to the Mid unchanged - IE you're allowing the entire treble section of the signal frequency through to the mid.

If you cut the treble from 10 to 5, then so resistance is going to be applied to those frequencies and cause the treble to be effectively limited when going to the Mid.

If you put the treble, mid and bass to 0 - you will get nothing no matter how loud the master volume is. Because the 0 setting on each frequency adjustment is removing the appropriate portion of the signal totally.

The Treble, Mid, Bass are not boost cut - they are resistance blocks for specific frequencies. To permit the signal to go through to the end of the chain (master volume is AFTER the treble, mid and bass) unchanged you'd have to set all the knobs to 10. Otherwise what is essentially a bleed circuit removes specific portions of the signal.

allexcosta · #9 06-18-2011, 01:46 PM

Master and Volume at 10? You're not supposed to do that...

There's nothing wrong with your amp. It's a fairly underpowered combo that distorts and hisses. That's how it's been designed. Get a different amp or live with it... You shouldn't be attempting to use this amp in anything more than practicing and rehearsals with quiet drummers and guitarists.

::::BASSIST:::: · #10 06-18-2011, 02:11 PM

I have had an SX jag shortie. Drop some dimarzio model J pups in there and will definitely be an improvement for not alot of $.