Building a cab from a broken Rumble 800 Stage…

[Jake555]

Hey all! I hope not to be annoying with all these questions and that someone can help me!!

The amp head section to my rumble stage 800 is broken and unfixable, so I’m going to use the speakers to make a new cab and buy the Darkglass Microtubes 500w amp head. the amp head is 500w @ 4 ohms if I’m not mistaken. The speakers from the Rumble are 16 ohms each. As I understand it the two 16 ohm speakers will have the same impedance as one 8 ohm speaker, thus the amp will produce 250 watts.

That’s fine for me, I can buy a proper larger cabinet in the future when needed, but unfortunately I don’t know the wattage of the speakers as they don’t have it written on them. The rumble amp is rated as 400watts to the two speakers, does this mean they’re at least 200 watts each? If I get the 500 watt head which will be running at 250 watts, and the speakers are rated at 200 watts each, will the Darkglass blow the speakers in this case?

also, I emailed both Eminence AND Fender for the missing details, and haven’t heard back. Funnily enough the fender rep did reply to say that the amp would have to be replaced and isn’t serviceable, but wouldn’t reply to my follow up email about the wattage. Perhaps it be a secret hehe

 

[agedhorse]

Wait a minute, the amp is certainly fixable by any qualified Fender authorized service center. They are not that difficult to work on, and the parts are available to an authorized service center.

If you are determined to do this cabinet project, copy the internal dimensions and porting of the existing cabinet portion of the combo. The power handling of the new cabinet will be ~400 watts RMS, and it will be 8 ohms. Pretty good match for the Darkglass amp IMO, you only lose maybe 2dB of maximum SPL.

 

[Old Garage-Bander]

There is a difference between "unfixable" and a tech not wanting to work on it, or not being able to get parts due to being independent, aka not factory authorized. The other definition of "unfixable" is that the cost of repairs is more than one is willing to spend. So as @agedhorse advises, get it to a Fender factory service outlet for a proper repair estimate before you write off this rig.

The Rumble Stage 800 is rated to produce 800 Watts at 4 Ohms, not 500. It's a fine point because it is my understanding that both the 800 and 500 use the same speakers. So at at 8 Ohms, your power output is going to be greater than 250 Watts. This information about amp power ratings at different impedances is found in the respective user manuals.

It seems that you may be relying on information provided by others, and you may just be taking that information at face value. One can help protect themselves from such misinformation by being more proactive about understanding their gear. I'm not suggesting you strive to become more of a technical expert, but at a bare minimum you should read the manuals. At least then you will know what your gear is capable of doing.

 

[G-Dog]

.
Jake, have you had the Rumble Stage more than 2 years? If not, or if close, Fender might replace it under warranty. Try that first.

Otherwise, for the price of the Darkglass head alone you can just about get a whole new Rumble Stage combo and use the old speakers as an external cab to get the full 800 watts!!

Per the Rumble Stage 800 spec.s sheet attached below, the amp output is up to 400 watts (continuous~RMS) into two 16 ohm speakers and a tweeter. So, each speaker must be able to handle at least 200 watts each, so 400 watts together. IF you do replace the Stage's amp with the Darkglass head its 250 watts at 8 ohms won't be near as powerful as the Stage amp was, so no risk to the speakers. Just sayin'. Come talk about it at the Fender Rumble Club and get a free membership.

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[Rooster009]

Why build a new cab? I mean it’s not the broken part of the combo right? Why not just either get the amp section fixed, or replace it with another amp that will fit in the slot and match the cab wattage rating?????

 

[Jake555]

Wait a minute, the amp is certainly fixable by any qualified Fender authorized service center. They are not that difficult to work on, and the parts are available to an authorized service center.

If you are determined to do this cabinet project, copy the internal dimensions and porting of the existing cabinet portion of the combo. The power handling of the new cabinet will be ~400 watts RMS, and it will be 8 ohms. Pretty good match for the Darkglass amp IMO, you only lose maybe 2dB of maximum SPL.

Naah , not true my friend. The amp in the words of fender themselves is that the amp is “unserviceable”. They said if ANYTHING goes broken on the head section, they just replace the whole amp (if under warranty). Unbelievable, I know. And I bought the amp used at about 30 percent off so no warranty.
And yes, I’ll be running the 2 16 ohm speakers generating 250 watts, happy with that until I get the budget for a nice new cab.

 

[Jake555]

Why build a new cab? I mean it’s not the broken part of the combo right? Why not just either get the amp section fixed, or replace it with another amp that will fit in the slot and match the cab wattage rating?????

This is what I’m doing. When I made this post I was just spitballing ideas haha

 

[agedhorse]

Naah , not true my friend. The amp in the words of fender themselves is that the amp is “unserviceable”. They said if ANYTHING goes broken on the head section, they just replace the whole amp (if under warranty). Unbelievable, I know. And I bought the amp used at about 30 percent off so no warranty.
And yes, I’ll be running the 2 16 ohm speakers generating 250 watts, happy with that until I get the budget for a nice new cab.

It is serviceable, I’ve serviced quite a few of them, I stock most of the parts including the power module, but I’m also fully qualified and experienced.

Fender does an exchange under warranty warranty, but that doesn’t mean that out of warranty a Fender authorized service center can’t repair it. Fender doesn’t repair anything themselves in-house.

 

[Jake555]

It is serviceable, I’ve serviced quite a few of them, I stock most of the parts including the power module, but I’m also fully qualified and experienced.

Fender does an exchange under warranty warranty, but that doesn’t mean that out of warranty a Fender authorized service center can’t repair it. Fender doesn’t repair anything themselves in-house.

Well that sucks. Fender didn’t explain that. I tried to get in touch with my local official fender repair guys but they wouldn’t communicate with me AT ALL, other than saying I’d have to wait a couple months. They wouldn’t even say if it’s possible to replace the parts.
I already bought a new amp, but I suppose I could figure something out.

now you’ve got me very curious…
I spilled beer all over the head part of the amp, then it turned off and won’t power up. So probably the upper most part of it is fried, whatever that consists of, including the screen. What would you estimate in USD or CAD replacement parts and labour would cost for a repair like that? I know it’s hard to imagine what exactly needs replacing, but just looking for a ballpark. Thanks for your comment!!

 

[agedhorse]

If the beer got into the amp (something previously unknown to us), that could be a very expensive repair. I don’t know how much, depends on the extent of the damage.