Converting a BA115 to an extension cabinet?

Reynolds 101 · #1 12-25-2010, 02:33 PM

I just bought an Ampeg B Series 4x10, but I want to be able to use it with my Ampeg BA115, both running through the GK head.

Is it possible for me to convert this combo amp into a cab to use, and how would I go about doing so?

Any help is appreciated, Merry Christmas.

**ddbassGA** · #2 12-25-2010, 07:33 PM

I have a BA115 that the amp quit. I removed the amp from the cab to check it out and it kept blowing fuses. I suspect the output IC chips are blown. The amp section is in the shop but I suspect it wont be worth fixing.

Meanwhile, I'm using the BA115 box as a cab with my GK 400RB as a practice rig. The speaker wire comes out of the cab with a 2 prong female connector for attaching to the original amp. I hooked a female 1/4" to those wires and then I can connect it to any amp. Eventually if my BA115 amp section IS toast I'll mount the 1/4" female permanantly in the cab.

I don't see how you would hook up with original inputs. But for $5 in parts you could open it up, tap the speaker wires & install a 1/4 input and a switch to toggle between the inputs to the speaker -- BA115 head or your bigger rig.

comet9 · #3 12-25-2010, 08:55 PM

I use 2 ashdown 515 combos as speakers with a mag 600.I just tapped into the speaker leads with double pole double throw radio shack switches.The speaker is on the middle poles with the amp on one side and a new input jack on the other.one way combo,other way speaker.a side benifit is Im carrying two back up amps!Just make sure everything stays in phase(ground stays ground)

JimmyM · #4 12-25-2010, 09:12 PM

i wouldn't do it if you're planning to hook them together so you can blow large amounts of volume. the b410 will take way more power and the ba115 speaker will most likely not take much more than the ba115 is capable of putting out. i could be wrong about that, but generally they use speakers in those combos that don't take power like their standalone cabs to save on weight and keep costs down.

anderbass · #5 12-26-2010, 10:16 AM

Hey Reynolds, Jimmy has a good point but the easiest way would be to find the speaker wires and run them out to the rear of the amp somewhere, you may have to extend them.

Then cut and install a male and female speaker plug and jack in-line.

One of your 2 wires will most likely be black, connect these ends to the ground terminals of your plugs so they'll be in the same polarity to match other cabs.

Try to secure each of the wires to the amp somewhere so tugging wont disconnect them from inside.

You could then simply leave them plugged in to use the combo alone or unplug to connect the speaker to a separate head. If you do this without drilling any holes, the mod would be reversible to help out with your resale value.

With this method you could also use the combos amp section to power other cabs.

Same as using any amp or cab, just make sure you always account for proper ohm loads and power levels. I believe your combo has a 4 ohm speaker rated for 150 watt use.

BassmanPaul · #6 12-26-2010, 10:54 AM

Anderbass gave you the how but Jimmy gave you the why not.

Sorry IMO this is just an all round not to do thing. Combo amps invariably are too small for the speaker that is installed which are often 4Ω to get the most out of the combo amp. Trying to run in parallel with a 4x10 would be almost suicide for the combo speaker and, assuming the 4x10 is 8Ω, the GK will have to be able to run into 2.67Ω which I doubt it can.

If you want more than the 4x10 can deliver, sell the combo and put the money towards a second identical 4x10.

Edit: And merry Christmas to you too sir.

JimmyM · #7 12-26-2010, 01:28 PM

Quote:

Originally Posted by BassmanPaul

Anderbass gave you the how but Jimmy gave you the why not.

Sorry IMO this is just an all round not to do thing. Combo amps invariably are too small for the speaker that is installed which are often 4Ω to get the most out of the combo amp. Trying to run in parallel with a 4x10 would be almost suicide for the combo speaker and, assuming the 4x10 is 8Ω, the GK will have to be able to run into 2.67Ω which I doubt it can.

excellent point everyone else missed. for that reason alone it's not going to work. sorry to be debbie downer, but it beats tearing up a nice standalone combo to find out you can't do it.

Jerrold Tiers · #8 12-26-2010, 07:18 PM

if it's an Ampeg combo, and it does not have an extension jack...... that's because it isn't supposed to be used with an extension speaker. Not designed to do it.

You can use it as a head for a separate speaker, of same impedance as internal, but NOT BOTH.

BUT, usually an amp like that is also not "protected" as well as a head, etc, so you will be much more vulnerable to temporary shorts, etc, stuff that just happens at gigs.

Enjoying it as a combo is the way to go.