Using a bass combo as a speaker cab

Gjeddekake · #1 08-29-2010, 02:27 PM

Hi

I was just wondering if it's possible to use my Ampeg BA115HP as a speaker cab without heavy modification? Just bought myself a Markbass LMII, and all of my speaker cabs are out of town, and the only thing currently at my disposal is this Ampeg combo.

Any answers are greatly appreciated.

**colcifer** · #2 08-29-2010, 02:37 PM

From the quick googling I've done it seems like it doesn't have an effects loop but if it does, just connect the send of the Markbass to the return of the Ampeg.

Gjeddekake · #3 08-29-2010, 02:53 PM

You mean connecting the amp to the «bal. line out»? Just want to make sure so that both the amp and the combo doesn't blow up.

RickenBoogie · #4 08-29-2010, 03:09 PM

it all depends on what kind of outputs/inputs are on the back of your Ampeg combo. Ideally, you'd just disconnect the speaker from the combo, and plug the MB head in there, but that would take modification. Your only other choice is running the Markbass "through" the Ampeg, but NOT in the front instrument input. You'd want from the back of the Ampeg, "Poweramp In", or "line In", or "effects return"- from the back of the Markbass, use either the "line out" (not the Balanced XLR DI), or the "effects send", or "preamp Out".

Gjeddekake · #5 08-29-2010, 03:42 PM

How complicated is it to disconnect the speaker from the combo? Is it possible for a musician, and not a technician, to do it without any problems?

anderbass · #6 08-29-2010, 05:59 PM

One option would be to install a male and female 1/4" Plug and Jack like these In-line in your speaker wires:
http://www.parts-express.com/pe/show...number=092-316
http://www.parts-express.com/pe/show...number=092-134.

I'd install the female jack on the speaker side and the male going to your combos amp section. When these 2 were plugged in to each other the combo would still work just like always but you could unplug them to use your speaker with another amp (or even use your amp section with other cabs) Just make sure you always follow the amps recommended ohm load instructions.

You wouldn't necessarily have to drill any holes to install or mount the Jack, If your combo has a rear port you could use it to run the wires through, although you may have to extend the speaker wires if their not long enough.

MooseLumps · #7 08-29-2010, 06:02 PM

Just use the ampeg.

It's a temporary setup anyway, right?

Gjeddekake · #8 08-30-2010, 12:35 PM

Thanks for all the answers!

Just sent an e-mail to Ampegs tech. service, will wait for an answer from them before I start screwing around with the amp.

@MooseLumps: the problem is that I don't know when I will get my cabs back, and I'm eager to test out the Markbass.

**Lazarus.Bird** · #9 08-30-2010, 12:43 PM

Hope you told them you wanted to run your brand new SVT-CL through the speaker and not a mark bass amp. Their customer support is pretty bad as it is.

doctorpunch · #10 08-30-2010, 12:51 PM

I'd just use the combo man. It'll make the reunion with your cabs all the sweeter.

Gjeddekake · #11 09-01-2010, 05:59 AM

A little progress report:

Just dismantled the amplifier from the combo, and the only thing left is these two wires into the speaker cab (see pictures).

The question is: what should I do now?

lbwdog · #12 09-01-2010, 06:10 AM

Seems like a lot of trouble, but you are apparently anxious to use your new amp.

If those are the speaker leads, clip the wires a few inches from the plug. You'll have to splice the plug back on to return to using the combo later. Trim the insulation on both leads so that you can splice a speaker cable with a 1/4" plug at one end onto them. Make sure you tape each lead so they don't touch each other (If you don't want to smoke your new amp!).
Insert the plug into the amp's speaker out and play. Be careful to not overdrive the single speaker.

perogato02 · #13 09-01-2010, 06:21 AM

Quote:

Originally Posted by Gjeddekake

A little progress report:

Just dismantled the amplifier from the combo, and the only thing left is these two wires into the speaker cab (see pictures).

The question is: what should I do now?

Connect a jack, plug and play

Gjeddekake · #14 09-01-2010, 06:27 AM

Ah, okey. Don't care to much about the combo being put back together, someone spilled rum and coke in it a couple of years ago, so the amp in the combo was about to be discarded soon anyways.

And no need to install a female jack? And how big is the chance of smoking both the amp and the improvised speaker cab? Is the splicing of the speaker cable a complicated procedure?

Sorry for all the (dumb) questions, I'm kind of new to modifying amps.

MooseLumps · #15 09-01-2010, 10:20 AM

If the leads from the speaker can reach the Markbass, then no. clip off the ends and solder on a 1/4" male jack. Polarity does not matter. insert it into the Markbass' main out and reduce the volume to nil. Attach a bass and turn the unit on. Listen for anything out of the ordinary or strange smells. turn up the volume slowly. if there are no issues, rock out.

If they wont reach, then either splice them to the severed end of a speaker cable, or install a female jack.

Chance of smoke is minimal if you don't let wires cross. Electrical tape is your friend.

Splicing is simple. Strip the wires to the metal, wind them around the stripped ends of the speaker cable or the solder tabs in the jack housing, solder, and go. If it's a jack, minimal wrapping with tape is required, but shrink wrap is best. If wires, wrap them separately, then together for a secure fit

MooseLumps · #16 09-01-2010, 10:26 AM

http://www.mmxpress.com/technical/connections.htm

Gjeddekake · #17 09-01-2010, 02:40 PM

Okey. So there is something i don't quite understand here: I'm supposed to twine the two cables together and solder on a jack, right? But what do you mean with «don't let wires cross»? the two wires I'm gonna solder together?

MooseLumps · #18 09-01-2010, 04:14 PM

No.
http://www.youtube.com/watch?v=UQm-A4hEIr4

you solder one wire from the speaker to one wire from the plug or the cable. wrap it with tape. solder the other wire to the other terminal or another wire from the cable. wrap that with tape. then wrap them together for stability.

If this is still unclear, you should probably just wait. you could hurt yourself or damage your equipment. I'm not trying to be a jerk, but this is serious business.

Gjeddekake · #19 09-02-2010, 04:29 AM

Aha, now I get it: I solder one cable from the cab to the jack, wrap it with tape, solder the other cable from the cab to the jack, wrap it with tape, then wrap them with tape together.

Just dissected a broken jack-cable to see where to solder the speaker cables on.

Gjeddekake · #20 09-06-2010, 08:37 AM

Just wanted to tell all of you who are interested: it worked!

Thanks for all the help guys, couldn't have done it without it!