My amp is clipping and I don't know why
 

I recently purchased a used Aguilar AG 500 amp and a Bergantino AE410 cab. My problem is, when I play my bass at moderately high volumes (master knob at about 10 o'clock) my clipping light goes off and it distorts a bit. This also happens when my master is at the lowest possible setting. Turning the gain down helps the problem slightly, but not a whole lot.

When I first noticed the problem, I was plugging the Aguilar in to 2 sort of low-grade, mismatched cabs (a Carvin BR210, and an Acoustic B410, rated at 4 ohms and 8 ohms respectively, and I tried running them both parallel and in series). I thought that the difference in impedance was making something go all wonky and causing the clipping, but it is continuing to clip with my Bergantino, which is rated 800W at 4 ohms (my amp puts out 500W at 4 ohms). So I am stumped.

Am I clipping the pre? Could there be a loose connection somewhere? I don't know much about this sort of thing, so any help at all would be appreciated.

What makes you think that there is a problem? What you describe is a normal behavior.
Preamps clip on attacks. It has nothing to do with master or whatever cab you plug and everything with input gain.
If you think it clips too early, use the PAD switch.

The clip light on the AG500 is only for the preamp so you either have the gain control too high or you are using an active bass and boosting the onboard EQ too much. This is assuming that a) if you are using an active bass, the battery is fresh and b) the head is operating normally and the total impedance of the speaker cabinets is greater than or equal to 4 ohms.

It's also worth noting that channel 2 is supposed to distort.
As is the case with most gear, you'd save a lot of time by reading the manual that explains all that in detail.

EDIT: Nevermind. Don't know what I'm talking about and am getting some coffee.

it's far too early to be drinking coffee in Knoxville

I am using an active Spector Euro 6LX (not sure how fresh the battery is; I'll try changing it) and the impedance on my head and cab match.

Have you tried just plugging into the amp without any speaker load?

When you were using the 2 cabs, one at 4 ohms, and oe at 8 ohms, at that time, you WERE running the amp below it's minimum impedance. I don't know if that's relevant to this problem, or even if there is a problem, but that 2.6 ohm load you were running, may have caused issues. NEVER run an amp below it's minimum impedance.

And one step further, that amp is NOT stable below 4 ohms. If you ran it with those 2 speakers and are now experiencing problems it might be wise to discontinue using the amp and taking it in for a look and service.

Thank you for the insight everyone. I hope the problem does not persist, but if it does I guess I'll have no choice but to have it looked at.

Dial the gain back, dial the master up. Problem solved. I don't know if this one does, but some amps just clip on extremely low gain settings.

I am positive that this has nothing to do with the power amp.

If you weren't running the 2.6 ohm load at loud levels for an extended period of time, you probably don't have to worry.

This is good advice! On the AG 500, the preamp starts to ciip pretty early if you have a high gain bass. Use more of the master volume and use the input pad to help.


DB

When I used my Ag500 with my Sadowsky I used the -10dB Pad. That was the key to have the gain up higher without clipping the preamp.

Pedro

Thanks again for the help guys.