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View Full Version : Fender Rumble 150 Head - Stupid Question



ghsky1
05-09-2012, 08:57 AM
I really love the sound of my Rumble 150 combo but wish I had more power. So I came up with this idea of trading it in for the head only version and plugging into a power amp, something like the SWR Power 750. Then I could play through a 4x10 and 1x15 stack.
Is this even possible? If it is, is it something worth doing? I just like what I hear out of the combo. I'm sure it would be a bit different as it comes out of something other than the cab/speaker configuration I now have.

Basslad
05-09-2012, 10:01 AM
Hey ghsky1, I haven't really pondered this one thoroughly, but I sense GAS which is perfectly fine. Wouldn't it be easier and cheaper to trade up to the Rumble 350? If you need a pro rig, then perhaps going with 150 head isn't the best idea. So I guess you would need to ask yourself what "wish I had more power" means.

TobiasMan
05-09-2012, 10:28 AM
When you mention trading your Rumble 150 combo for a head only version, I'm assuming that you mean a Fender 150 power amp only. Make sure that the Rumble and SWR will play nice together before you start plugging things together.

I know that with my Eden gear, I can connect the Headphone Out (quite a hot signal) from one amp and plug it into the Aux In in another one. Once the level on the second amp is set, the Master Volume on the first amp controls both amps.

I see that the Rumble 150 is power rated at 4 ohms and don't see that it is capable of driving a 2 ohm load, so that really doesn't give you the option to add more cabinets to that amp or you'd be at less than 4 ohms and damage the amp. Adding cabs makes much more difference to overall volume than adding more power. You are attempting to do that via the second amp, but if your amp was capable of driving more than one cab, you'd get much the same effect with one amp.

Your Rumble has an RCA connector for its Aux In. Make sure that if you are trying connect to a second amp that either it has an instrument plug Aux In or that the second amp's input can accept the signal from the headphone out from your Rumble.

Never plug the power output from an amp into another amp!!!!

ghsky1
05-09-2012, 04:36 PM
OK, so I posed this question on the Fender forum under the bass amp section as well. A guy that goes by "brotherdave" and has his own website brotherdave.com (http://brotherdave.com) answered with this:





YES with one caveat. You need speakers connected to BOTH the Rumble and SWR power amps.

While this means adding an additional cab, it doesn't have to be much of a cab. About any smallish 4 OHM bass cab will handle the 150 watts of that Rumble, perhaps put a 2x10 tilted in front of you for a monitor or put it firing toward the drummer so he can hear you better. (I've done both those things at one time or another.) Or of course just put it behind you with the cabs fed by the SWR.

Yes you can use a PA monitor style cab with the Rumble, but will probably want to change out the speaker in it to a bass speaker. I'd use the bigger/better speakers for the SWR.

Be sure to power BOTH units from one power conditioner or at least from the same power strip to avoid ground loop hum.

Here is how to connect them. The SWR is a bit unusual in that it has an XLR INPUT but does NOT have an XLR OUTPUT. The Rumble has an XLR out. To connect the two amps just use a short microphone cable of good quality to connect the RUMBLE XLR output (more typically used for PA Feeds or Recording Feeds) to the XLR input on the SWR POWER 750.

REPEATING, be sure to have speakers connected to both amps.

Ideally use a single 4 OHM cab on the Rumble (4 OHM MINIMUM is spec'ed on it) and a 4 OHM cab or stack array yielding a 4 OHM load for the SWR. Using 4 OHM loads on both power amps should get about all the rig has to give...900 watts! I know that the SWR POWER 750 is spec'ed to have a MINIMUM 2.6 ohm load but 4 OHMS is typically the lowest you can go using stock cabs without going below 2.6 OHMS, so if you use one 4 OHM cab or two 8 OHM cabs for a 4 OHM load with both amps you'll be about where you need to be load-wise on each. The SWR POWER 750 does 750 watts and the RUMBLE does 150 watts when both are fed in their own 4 OHM loads.

If you need a PA feed you would have to use the SLAVE phone jack on the SWR. I'd suggest acquiring a direct box and add it between the SWR and the PA snake box for the PA feed.

Actually having a rig like this is a REALLY good idea. When playing indoors in a smaller venue you might only need the Rumble rig and can feed the PA with the Rumble XLR out. When playing outdoors or in a huge room you can add the SWR and additional cabs.

My personal rule is NEVER GIG WITHOUT A BACKUP FOR CRUCIAL GEAR. That means having more than one instrument, power amp and cab. At the least I always have something I can feed direct to the PA should there be a failure in the amp/speakers. Having a two power amp rig like this means if there is a problem with one amp, you still have the other as a backup.

Since the RUMBLE is doing the PREAMP work in this rig, if it is the Rumble that fails you would need some sort of backup preamp to feed the SWR phone jack input. Anything like a Tech 21 NYC Bass Driver, Line 6 Bass Pod or even a $40 Behringer BDI-21 would serve that purpose and I'd always have at least one with me. Any of these pedals would get you through the gig and nobody but you would even know that there had been a problem.









I thought it was a very informative answer and just wanted to pass along the info.
Any other thoughts on the subject are always welcome. This is all a learning experience for me.

Elmeaux
05-09-2012, 04:45 PM
You can never have too many Rumbles. :p

Ditto
05-09-2012, 05:57 PM
You can never have too many Rumbles. :p

I don't know...... I ate at Panda the other day and an hour later I felt wayyyyyy tooo mannnny RUMBLES!

:)

Elmeaux
05-09-2012, 06:12 PM
I don't know...... I ate at Panda the other day and an hour later I felt wayyyyyy tooo mannnny RUMBLES!

:)

Yes, I knew this answer would happen...it was just a question of who...

:p

TobiasMan
05-10-2012, 11:43 AM
Glad that someone has confirmed that the Unbalanced In plug on the SWR Power 750 will accept the Aux Out from the Rumble.

I don't know if the volume control on your Rumble controls the level of the Aux Out (it may not, because the Aux Out is sometimes ahead of the volume control in the signal path). If it does, then the connection is pretty simple.

Bass -> Rumble input -> Rumble Aux Out -> SWR Unbalanced input. Attach cabs (no less than a 4 ohm load on each amp), set the relative volumes between the two amps with the volume on the SWR and play. Obviously, watch the LEDs on the SWR to ensure that you are not overdriving it.

If not, then you may have to juggle both volume controls if you change the volume output you want from your rig.

As noted, this gives you a modular rig that would allow you to take only the parts of your rig that are necessary, scaling down to the Rumble and perhaps a 210, or the Rumble, the SWR and a 410 for a larger venue or both for an outdoor event. :cool:

Click here for the SWR Power 750 (http://support.swramps.com/manuals/pdfs/Power_750_om.PDF) manual.