Amp and cab portability/technology

rsvmark

So last night, our bass players combo died. It was a traditional ampeg combo type unit. A local chap came to the rescue with an Eden amps Nemesis head and a matching EX210 cab. So I have been gigging off and on for over 20 years and my traditional thinking for bass players as far as I am aware is for big cabs, big speakers and large wattage etc. The best bassist I ever played with had a trace Elliot head which weighed a ton and a bloody huge cab (can't remember if it was trace or other but was equally huge) and to be fair was a good sound. This Eden amps rig was utterly brilliant. Clear, clean, powerful, deep bass, and for a gigging musician, it was tiny. The 2x10 cab was half the size of my Marshall, really light and the head was half the weight of mine. I has got me thinking today that bass amp technology may well have moved on a touch. The cab in particular was feather weight. While modelling offers alternatives, cab technology hasn't really moved on? Discuss. To be fair, my perception is that several folks on here have gone to 2x12's or smaller cabs and miking up. Any thoughts?

slacker

Bass stuff tends to use class d power amps instead of valves with huge transformers and neo speakers instead of alnico or ceramics. This cuts down weight. Some cabs have porting to increase bass in a smaller size.

If you must have valves then weight will be an issue, same with alnico. I have a 2x12 combo that weighs 80 pounds. Sounds awesome. I have a small 15w head and a choice of 1x12 and 2x12 cabs I also have a 4 w combo and a half w head and remap thingy.

All of the above could be replaced with a helix kemper etc.

The choice is yours Google helix and watch some videos

digitalscream

I use a Matrix NL212 cab (2x12"), which is lighter than my amp head - that's saying something, because the amp is a Jet City JCA22H. It also sounds very much like a V30-loaded cab (it's not, it's got neo speakers in it which are modelled on the V30).

Cab tech has moved on, but most cab manufacturers haven't.

ICBM

slacker said:

Bass stuff tends to use class d power amps instead of valves with huge transformers and neo speakers instead of alnico or ceramics.

It's not the power amp type which is important, it's the power supply. In fact, a Class D power section is only very slightly more efficient and lighter than a Class AB one of the same power, so I'm quite puzzled by why Class D has become so popular for anything less than KW-range amps. The big difference is with Switch Mode power supplies (SMPS) which are a fraction of the weight of conventional ones since they don't use a heavy power transformer.

My little Ampeg Micro VR bass head is SMPS, Class AB, and produces 200W from under 10lb weight including a traditional plywood head box. MarkBass amps are even lighter without the head box, and their older ones are also Class AB. (They appear to have changed to Class D now.)

It's difficult to make valve amps this light, because even if you used a SMPS there would still need to be an output transformer - even though it's the smaller of the two.

Neo speakers and modern highly-braced thin wall cabinets (eg Barefaced) also make a big difference, certainly. One of the big problems with older mid-market cabs is that they tended to be MDF or particle-boad, which is much heavier than ply for the same strength - although also stiffer, so it doesn't need as complicated bracing and hence is cheaper to make. For guitar cabinets bracing is usually the opposite of what you want though - they tend to sound better when they resonate, so it should be possible to make guitar cabs much lighter.

simonk

You don't have to go down the modelling route to save weight. I have a little Quilter 50w head which is about the size of two pedals, weighs next to nothing and sounds great. Pair that with a neo cab and you have a very lightweight rig.

Bonceyrogs

+1 on the Quilter amps, I bought mine purely to cut down on the total weight of my gear. The sound quality of even the cheapest gear nowadays is getting better by the year. You can get lightweight ported cabs for cheaper now too, and they can sound as great as heavier gear.

I run my Quilter Tone Block with a 150w 1x12 cab and it sounds immense. I haven't carried a tube amp to a gig in about 2 years now.

guitarfishbay

While I won't claim its the best cab ever, my Hartke Hydrive 410 is easier to move about than my Mesa 2x12.  There isn't that much choice yet for lightweight guitar gear yet, hopefully people will develop it more now that there's an increasing shift to digital

Danny1969

My cab is quite heavy on the way to a gig, mainly cos it's got 4 or 5 beers in it. Bit lighter on the way back

The Fender Princeton valve amp is small, relativity light and sounds massive, that's the amp I want 

Hoof

Hayden Mofo 30 though a Harley Benton 2x12 stood on its end. Love the convenience of the Mofo more than the sound. Sounds nice at polite volumes but seems to shelve off low end as you turn it up loud. I'd like a nice compact, cleanish head to use as a platform for pedals.

fretmeister

Ive got a Darkglass M900 head and two tiny Barefaced Retro 1x10 cabs.

And it's loud as hell with massive bass.

Sporky

ICBM said:

In fact, a Class D power section is only very slightly more efficient and lighter than a Class AB one of the same power

Isn't class AB around 60% efficient? Theoretical maximum efficiency (ignoring classes G and H) is about 78% if I remember correctly.

Class D runs 85-95% real-world efficiency.

John_P

I do like the trend for lightweight bass gear - my GK combo is plenty loud and silly lightweight - perfect for the deps and function gigs I do.      
I have small guitar rigs but still find myself preferring the stacks even with the weight and bulk - old habits are hard to break I guess. 

BGG

I've got two DV Mark small 1x12 speaker cabs with Neo speakers, I can lift them with one finger.

ICBM

Sporky said:

ICBM said:

In fact, a Class D power section is only very slightly more efficient and lighter than a Class AB one of the same power

Isn't class AB around 60% efficient? Theoretical maximum efficiency (ignoring classes G and H) is about 78% if I remember correctly.

Class D runs 85-95% real-world efficiency.

I think Class AB can get a bit better than that if it's biased closer to Class B than Class A - I forget the figures.

My point is that for musical instrument amps (especially guitar amps) it's not really that important, because they're relatively low-powered and there's really no need to operate that close to the edge - if it was 60% for Class AB vs 90% for Class D you would only be getting 50% more usable power output for the same input with Class D, and that's really neither here nor there for most purposes, when a cranked 50W amp is probably already too loud.

It does start to make a big difference when you're into multi-KW power amps, obviously.

Sporky

Ah, I getcha. I think I tend to read amp stuff from an installation point of view which isn't always "right". For that it's less about the efficiency in terms of power consumption and more that anything under 100% is heat generation. That matters even with small amps (by which I mean half-width rack, up to about 200W output - which is just over 1kg for the two options I use most).

Also lack of cooling fans is useful to me.

ICBM

Sporky said:

Also lack of cooling fans is useful to me.

Fans are something that really annoy me about many modern amps, including my Ampeg Micro VR. (It's actually more for the SMPS than the power amp I think.) At these power levels there should be no need for fan cooling if the amp is properly designed. It's annoying from a noise point of view, and because it introduces another potential failure mode - and because the amp also tries to act as an air cleaner and gets full of all sorts of crap.

Although that was worse in the days before the smoking ban - tobacco smoke residue is not only a good thermal insulator so it tends to prevent the very cooling the fan is there for, but it's also electrically conductive. I've seen some spectacular failures caused by smoke residue build-up in things like power amps which have been run for years in pubs and other venues. I have a pic of the worst one, it's actually really unpleasant to look at...

Funkfingers

My back and car were both very relieved when I abandoned a Marshall DBS stack for a tc electronic Staccato '51 and RS210. I waited years for tc to introduce an RS115 cabinet. Now that they have, I feel able to manage without one.

Sporky

Fans are ridiculous. I can buy a 1U 4x200W convection cooled power amp that'll stack with 41 of its friends in a rack cabinet with no gaps and run 24/7 for years. Why does a 200W amp in free air need a fan?

ICBM

Sporky said:

Fans are ridiculous. I can buy a 1U 4x200W convection cooled power amp that'll stack with 41 of its friends in a rack cabinet with no gaps and run 24/7 for years. Why does a 200W amp in free air need a fan?

Exactly!

The answer I assume is because it's badly designed with borderline-spec components, an inadequately-sized heatsink and a poor convection cooling path...

Sporky

And my Genz-Benz Shuttle is 300W and no fan. Well, 175W as-is, 300W with an extension cab.

Also it's ridiculously loud for being easily carried with one hand. Not gigging-loud, but astoundingly loud for the size and weight, even with a fairly conventional cab (at a guess 12mm ply or MDF).

The little half-rack 200W-sh power amps are under £300, but I s'pose that's still a fair bit compared to what guitarists and bassists are used to paying, and you'd need a preamp of some sort.

ESBlonde

I guess when we were all denim clad young guns back in the day, the 4x12 stack was as much a macho statement as a sound requirement (the options were all heavy too). We got addicted to that roar and a push in the back when we hit the first chord.
Now a large proportion og gigging musicians seem to be .....of a certain age, the smaller size and light weight of modern engineering have a certain appeal.

Sound reinforcement and Bass players have been reaping the benefits and the improvements in driver design mean a single driver in a ported enclosure will outperform an old lower powered driver in a ported/vented horn enclosure many times it's physical size. Remember the original 4x12" cab was cut down from the 8x12" cab needed to absorb a 100w valve head because the 12" celestions of the day were really updated juke box drivers but all that was available.

Many of us are still somewhere between the heavy valve driven monoliths and the computerised matchbox tone generator. One day there will be a hand full of valve guys and everyone else will be making music on a laptop.