From what I can tell, I get a fair few hits on this site from people wanting to know more about the Boss MG-10 amplifier, and since I have had one since they came out in 1989 (and now have three) I thought I’d post about what I know about the amp, starting with some basic facts.
If you didn’t already know, the Boss MG-10 is a small solid state guitar amplifier. Solid state means it doesn’t use valves (or vacuum tubes) and that fact alone will alienate a whole bunch of guitar players, but…whatever.
As the name implies, it’s a 10 watt combo amplifier, meaning it can output up to 10 watts into its two five inch speakers. Although it has two speakers and looks a bit like the stereo Roland JC amps, it is not stereo – the two speakers are wired together in parallel to make a 4 ohm load.
The cabinet is closed-back, and the front baffle has a cutout between the two speakers which stops the whole enclosure from being “sealed” without being “ported”. If you don’t know what I’m talking about, honestly, don’t worry. You can just see the cutout in the photo below, a circle between the two speakers at the bottom of the baffle.
Being a closed-back cabinet there is nowhere to stash the hard-wired mains power lead, which is one of the most annoying things about it, given that it’s a small amp and therefore portable. Mine came with a plastic strip on the cable for wrapping the cable up, and it worked for years before falling off. Mine also came with a moulded UK 3-pin plug. You can wrap the cable up and stuff it into the carrying handle, but then you can’t use the carrying handle…
If you look at the photo above you can see my original amp on the right. I moved the carrying handle from the top of the amp to the side so that I could stand my Yamaha REX-50 effects unit on the top. The amp on the left was a later acquisition and has the handle on the top where it was intended to be.
As is standard for lots of small combo amps the carrying handle is actually what holds the amplifier chassis inside the cabinet. Over time the black steel parts of the carrying handle rust, so if you see an amp like this second hand and those parts are rusty, don’t let that put you off.
The cabinets are made of particle board and are fairly sturdy, but not indestructible. One of mine has been damaged in the past, but more of that in a different, forthcoming article. The cabinets are covered in black textured vinyl with black plastic corner protectors. The speakers are covered with black nylon mesh which has proved very sturdy on mine over the last 30 years.
According to the manual the amplifier measures 32 x 24 x 17 cm (about 12.5 x 9.5 x 6.5 inches) and weighs 4.9 kg (10lbs). The amp itself is quite balanced (big amps tend to be heavier wherever the transformer and speaker magnets are) and is a really cool size.
It has seven controls on the front for shaping the sound – gain, volume and master volume controls and bass, middle and treble and presence EQ controls. If you are familiar with guitar amplifiers you will know that more gain and volume = more overdrive/distortion/fuzz (like a punky, heavy-metal sound). Master volume controls the overall volume. With all the EQ on zero there is no sound at all. You can “pull” the master volume control to engage the “warp” function which kicks in a different type of distortion, and removes the bass, middle and treble controls leaving just the presence doing anything. Presence is like super-duper treble.
There’s one input, a headphone jack (which I’ve never used) and a power switch. Being solid state it comes to life immediately after you switch it on. The seven controls have blue-topped control knobs. All of mine on my original amp survived, but the two I subsequently bought have both lost at least one knob (see the presence knob below), and just about every one I’ve seen on eBay has been missing one or more knobs. This may have something to do with the “warp” control being on a pull-control and eventually being pulled right off forever. Sometimes too the knob remains but the blue top goes missing. Boss/Roland do not make replacements.
I’ll make a video one day about the sounds as it’s just easier to play them rather than describe them, but suffice to say this amp, with its 10 watts of solid state power and two five inch speakers is NOT a heavy sounding amp in the same way that a 12 inch speaker can be – those two five inch speakers just don’t deliver a lot of bass. But you can get a huge variety of sounds out of the amp, from clean to exactly what you can imagine warped distortion sounds like. It’s also really, really loud for a little 10 watt amp.
But it won’t sound be loud enough to compete with a live drummer, and it won’t sound like a plexi, or an AC-30, or a twin reverb. It sounds, instead, like itself. If you have bought one and are wondering whether it’s any good or not, it’s a great amp, trust me. But just remember that it’s a 10 watt practice amp, not a classic tube stack or anything else. Let it do its own thing!
As I said I’ll make a video about the sounds one day. In the meantime check out some of my existing videos of the amplifier.
Boss never made any variants of the MG-10, for example a head-only version. So if you see one of those, someone got out the hacksaw. They did make the MG-80 a few years later, which is an 80 watt version with two 6.5 inch speakers. I have one of those two and they are bigger and heavier amps. I’ll make a video of that too one day.
Watch this space for an article about the limited information I have about the circuit.