Who gigs with a combo amp?

[cassius987]

I'm really tempted by a Rumble 200. But after my last outdoor gig, I'm worried it wouldn't have performed as well as my Barefaced (I had no PA support).

[Kiddwad57]

It also seems to be about the same size and weight range as your current rig.

[cassius987]

It also seems to be about the same size and weight range as your current rig.

Yeah. I just want it all in one piece!

[Kiddwad57]

Grab and go! Those barefaced cabs seem really great and a high standard to meet. JPS seems to dig his markbass. I have a friend who has one and it's really powerful. Sounds good too. Maybe something to contemplate.

[cassius987]

I dig Markbass tonally, but the carpet upholstery doesn't pair well with our kitties, I'm afraid!

I'm thinking about ordering a Rumble 100 from Sweetwater to see if that can do the trick...

The main thing would be to really get a sense of many watts of power I truly need. Is there a clear enough relationship between my TH 500's Master control and its output to figure that out?

[iiipopes]

It's not about power, per se. It is about power in relation to tone and weight. The new toroidal or "Class D" amplifiers can put out a ton of power without a lot of weight. I believe that is the focus of this thread - which class D at which power level. And there are several good to great amps out there. What to look for? Every amplifier has a "0" on the volume knob, and should have a smooth ramp through the range of the knob up to maximum volume, whether the power stage is 5 watts or 500 watts. If the taper of the input stage is "all-or-nothing," so that it gets too loud too soon, or if it is difficult to fine-tune levels as the volume is rolled up, the problem could be one of the following:

1) the pre-gain/post-gain balance needs adjusting (start with rolling up both knobs the same amount to the desired volume then adjust from there for the "drive" character desired);
2) the bass instrument output is too hot (usually only a problem on really jacked active basses);
3) the wrong jack on the front panel is being used (I am guilty of this one; breaking old habits to use the "active" -10dB padded input for my active bass);
4) separate head/speaker cab mismatch in either impedance or efficiency (should not be a problem since this thread is about combo amps, unless extension cabs are routinely used);
5) dimed tone controls, instead of starting with all tone shaping at 12:00 setting and adjusting from there (if the amp has an EQ bypass, start from there to see if the inherent tone of the amp is compatable with the player/style/repertoire/instrument);
6) worn out/wrong tubes (again, not an issue in this thread, but for overall discussion, since some combo amps have a tube as the primary input gain);
7) standing wave issues in the venue with boomy notes, requiring the amp be repositioned, in some combination of changed distance away from a wall or corner, off the floor, tilted back, aimed at a more open spot in the room, etc.).

If none of these "fix" a too-loud-too-soon problem, then the issue may be an amplifier design problem instead of a too-much-power problem.

Regarding comments about power, too little power can actually be detrimental to a good performance with a combo amp. Actually, a well designed higher-powered amp is better for combo or other gigs so that the amp runs well below stress levels, runs cool, and runs clean with minimal noise for maximum life of both amp and speaker.

The reason this is important for solid-state bass amps is due to how they clip. Vacuum tube amps "soft clip," or naturally compress as the gain increases, because the tubes trade off the voltage to get the higher gain for more amperage, but due to the limitations of the circuitry, the amp can't continuously cycle the power (over-simplified, but work with me), resulting in heat, but the tone stays "warm" due to the even-order harmonics induced from the tubes trying to pass the higher gain, but failing, resulting in a ramp-shaped distortion trace. Rock on!!

By contrast, solid state amplifiers (not including some newer MOS-FETs and other power semiconductor devices that have different characteristics) traditionally clip. All-or-nothing. So one moment you have a proper gain and tone characteristic, and the next moment with the slightest gain up it is clipped off and harsh, sending odd-order harmonics to the speaker, which we perceive as fizz or roughness, not the warm, singing presence of a tube amp.

So...due to these differences, and remembering that every doubling of perceived loudness requires about 10 times the power to get the same tone out of a combo amp through the volume range, an Ampeg Portaflex gets by with 50 watts due to the soft compression and the amperage/voltage tradeoff, but a solid-state amp will require something approaching 250 to 500 watts to stay clean before clipping. This thread is about light weight solid state combo amps, not about tube combo amps, but the discussion is necessary to determine what a player may need out of a modern amp.

For those into cars, it is kind of like the difference between slightly softer-walled racing tires on wire rims from a previous generation compared to modern hard tires on alloy rims. The softer setup will let you know when you are approaching the limit, so it can be easier and a little more forgiving to drift through the corners, so the driver can keep up with the harder setup; but the trade-off is that unless the driver of the harder setup knows exactly where the limit is, he/she will break loose and the softer setup guy will drive right on by.

Finally: the last time I was on an amp safari, it took me six months to find one I like, when I was downsizing weight a few years ago myself. Be patient. What is a couple of months of research and travelling to hear different amps in return for a purchase that is going to last a decade or two, to say nothing about the gigs to pay for the depreciation of the amplifier over time.

[Kiddwad57]

That's a really informative discourse on amps! I used to fantasize about a combo cab in Vox style for my 1965 AC50. Tubes are what's happening! I had the opportunity to compare my Vox and a GK mb150s on a gig. A guy brought his down to the blooze jam. It was sad because the AC50 through an efficient Vox V115 cab totally pummeled the GK in this context. In the end I bought a GK because my needs changed and I haven't used the Vox in thirty years. I should probably sell it.

My cat, bless her soul, used my 2x10 Bagend for a scratching post. I removed the carpet and had it sprayed with pickup truck bed liner. Looks at least as good as new, sounds great, but I hate lugging it around and should probably sell it, too.

Another combo suggestion: What about the quilter bassliner? I haven't even played through the head let alone the cab, but they seem to have a lot on the ball.

[iiipopes]

It was sad because the AC50 through an efficient Vox V115 cab totally pummeled the GK in this context.

You point to the other half of the equation: efficient speakers. Again, the Ampeg Portaflex had a specially designed compliant speaker for the particular cabinet that was efficient for its time. A good efficient speaker of proper impedance and compliance properly integrated into a well designed cab will do more for a system than merely adding more wattage.

[Happyface]

The risk with using a combo amp is that if the amp or the speaker fails, the whole until is compromised to some extent. For important shows, i like to have two speaker cabs, an amp and a small backup head. That way I'll probably always be OK if one part fails.

Of course, you can simply switch over to your DI if the combo fails and you are playing through a good PA. If the FOH is sketchy, having your own redundancy is comforting.

[Kiddwad57]

Back in the day folks used to pack a spare showman in the van. I've seen them used for everything including PA.

[iiipopes]

Back in the day folks used to pack a spare Showman in the van. I've seen them used for everything including PA.

What do you mean, "Back in the day"? My band still keeps one in the rehearsal hall - a blackface. It does everything from spare guitar amp, to driving a Leslie, to bass duty, to, yes, monitor if not front-of-house PA.

[Kiddwad57]

There was a band in So. Illinois called Butter (how'd they come up with that?) that used one as a PA head with a couple of Altec Voice of the Theater cabs. Sounded fantastic. The rest of the band was using Sunn Coliseum stacks.

[Happyface]

There was a band in So. Illinois called Butter (how'd they come up with that?) that used one as a PA head with a couple of Altec Voice of the Theater cabs. Sounded fantastic. The rest of the band was using Sunn Coliseum stacks.

Wicked front & back lines!

At least fine looking ....

[Billsbro]

I have the Rumble 500 C and like it although the gain and volume pots are a bit scratchy (I guess it is common).
Great sound. Flexible. Light.

I just added a Mesa Boogie Powerhouse 115 cab to it and it really sounds amazing.
(I think I will eventually get a Subway 800+ head to power the 115 so that I have two rigs to mix or match)

But it is hard to go wrong with a 200C or 500C Rumble.

[farace]

I'm very happy with my GK MB212-II. At 41 lbs and 500 watts, I lost almost 100 lbs and gained 150 watts over the Ampeg SVT-III/SVR215 I was using.