Started playing bass 2 months ago. Picked up my starter gear at Music Go Round. Got a Fender Rumble 25.
If I knew then what I do now, I’d have gotten a Rumble 40 (or similar).
Should I go ahead and replace with a Rumble 40 now?
Give it more time practicing with the undersized amp? (Maybe hold off until I finish B2B.)
Other good recommendations on a better comparable practice amp?
Hold off and keep your eye out for a used Rumble 100 or equivalent.
What Barney said. I found a used Rumble 100 and love it
Local Music Go Round has a Rumble 100 available right now for $200…
Older one with the black grate front. I believe 1x15.
Good point to look for a used Rumble.
But at the end of the day, which power of amp you want/get is really a matter of what YOU need. That’s all that counts.
In other words, do you need an amp for playing in jams or a band? Or do you intend to be strictly an at-home/bedroom player?
Answers to these questions will chart your path.
FWIW, I have a Rumble 40 and it’s perfect for me. I have no plan/need for anything more powerful. YMMV
There are several versions of the Rumble’s. The current ones are good but a lot of older ones are not so interesting.
I’m now locked into my amp brand but if I’m still looking I’d most likely start with Boss Katana 110. Continuous 60w and peak at 110w. It has 1w mode for a late night practice
I’ve kinda got heart set on the Ampeg 2X10. Next payday.
I went from 25 to 40 and fine for home and church hall type jams.
Good question. I don’t know yet where this journey will take me.
I have no aspirations to be regularly gigging or anything like that. Would like to do some low-key playing with other people. Possibly just jamming with friends at each other’s houses. Very likely join a local SoR adult band.
All that said, it’s always cool to have a very compact practice amp. I bought a used Ampeg BA108 V2 for my GF and it’s a very nice little tool.
Take your time. Play as many as you can find. There’s no rush. Seek out what sounds best to you.
I know it’s rare coming from me but, don’t buy anything for a long term future. Just look and feel a few months ahead.
Your preference will changed and you’d ended up buying another anyways. Give yourself just enough wiggle room for growth and worry about later, later.
I would recommend keeping the Rumber 25 till it blows, because it will in a matter of time. That buys you time to get a better amp to replace it.
So much Rumble 25 disdain 
It’s a great little amp and sounds fine. It’s not loud enough to gig. That’s also fine, it’s a solo practice amp, which it is plenty loud for.
The tone is good and overall the amp is high quality; it’s just a beginner amp, and there’s nothing wrong with that.
Doubling an amp’s power results in an increase of 3dB actual volume. Human ears require a volume increase of 10dB to perceive something as twice as loud.
So in comparison, the Rumble 40 only adds about 25% more apparent volume over the Rumble 25. It’s not very much louder. Its chief advantage is it has a 10" speaker v 8".
At 6dB louder, Rumble 100 is about 1.5x the volume of the Rumble 25. As you go up in amp headroom and speaker size, the amps will sound better, but if you’re looking for volume you need to be looking at 10-20x more wattage instead of 2-4x more.
Yep. That’s the point.
Yeah - but tbh it seems rather pointless to buy just for that. Instead I’d look for the 100 (minimum) to get both the larger speaker and more headroom.
I don’t actually think the 40 sits in a great spot, market wise in this case. It’s a perfectly sized practice amp to buy first - but isn’t a huge advantage over the 25 to compel an upgrade from it.
I’d recommend instead the 100 or if gigging the 500.
In other words:
Great advice.
You have perfectly replicated my own thinking. Plus, the 100 weighs almost the same as the 40. So I got the 100 myself.
Yeah, the 40 seems like a great amp if you buy it first, but if you don’t, the 100 is the clear upgrade choice I think 
Meanwhile, nothing wrong with the 25. As someone above suggested, just ride it until the wheels fall off.
I love Ten’s. it strikes the balance between tight, low and fast. There are a few awesome 8’s but none are in budget and mid range price point. You gotta engineer the sh!t out of it to get awesome sound at volume.