Today I'm going to be showing you my early 50s Gibson B-I-9 guitar amplifier, which is about 10 watts or so. What's rather unique about it? Well, firstly, let me just say it's some sort of like a 50s fender champ on steroids. But the difference is it's got two little 6V 6s. As opposed to being push-pulled like a lot of amplifiers that I've got two output valves, they're actually in series. She's rather strange as you can see the plates tied together and only hit one tap. Usually one plate is connected to one side of the transformer, and another plate is connected to the opposite side of the transformer. There's a center tap to B plus, which powers them up. But in this case, that is not so. Another interesting thing about it is it uses an input pentode, as opposed to a 12aX7 being early 50s. It uses all octal valves. So yeah, totally an absolutely triode free. So it's only got really when you think about it, two stages of amplification, one valve being preamp, which is the 6sj7, and then it goes straight into the output section, the pair of 6V 6s in parallel. Like a lot of amplifiers of this generation, or that vintage, it has a valve rectifier, as opposed to diodes. So should there be, I don't know, a nuclear fallout, which renders all semiconductors completely unusable, assuming we still have electricity, I can still play guitar, isn't that lovely. Anywho, another thing about it, you can see over there there's a little thing that says speaker field coil. It actually doesn't have a permanent magnet on the speaker, it has a coil around it to magnetize it, which is rather unique. Well, it's not really heard of it much these days, but you know, back in the early 50s, I suppose it was relatively common, because magnets were relatively inexpensive, so I hear I wasn't there, I was born in 1977, so I can't speak from experience. Another thing, it's only got a single volume control, no tone control. If you sort of think about it, that control there is the master volume, because there is no preamp volume, you just control the amount of single going straight into the output stage. So as you can see, it's a relatively simple circuit. In the description, I'll give you a link to the flicker gallery that I've got, where I'll show how I restored it, replacing all the capacitors. I've got it pretty much for a steel, $100, about $500 shipped from the US, which isn't too bad for an amplifier of that vintage. I suppose they're not terribly well known, doesn't have fendron, it gives them only exactly known for their amps, but you know, it's very similar to the fender champ, as I mentioned, apart from the output stage. But it required a bit of work, it, yeah, it doesn't look like it'd been used in about 20, 30 years. The power cord was rolled up, and when I'm rolled it, it's just sort of flaked to bits, all the wax capacitors, and the electrolytics were all original, didn't risk even, you know, turning it on, with a very acrid, I just opened it up and replaced everything. But enough of me talking crap, I'm sure you want to hear what this thing sounds like, so I'm going to give you a wee demo. Actually, I lied when I said I wouldn't be talking anymore crap, because I, well, I've got to tell you about it now that I'm in front of it. There she is, sitting there on a chair with the curly table going into it. Let's have a look what's in the back here. I mean, we've got enough light, just flip it around. Alright, it's probably a bit dark, how, and I just smashed my elbow on a sharp corner. But let's not worry about me right now. There are the four valves, single volume control, two inputs, just on off switch. The very highly inefficient 8-inch speaker with the field coil, field coil to magnetise it. It's probably a good thing that's rather inefficient, means I can turn it up to 10 without the neighbours complaining unlike. If I was to play my high watt, going into my quad box, which I really can't turn up anywhere past about, say, very fun playing clean, or about there if I've got the preamp maxed out using my, um, range master clone. So this is one way to make enemies. This amp on the other hand is sort of neighbour friendly, because I can turn up 10. I don't end up suffering from tenitis, and I can still be on friendly terms with neighbours. So I'm going to warm this thing up. Plug in my 1975 Gibson Les Paul Red Sparkle Top with P90 pickups instead of the standard Mini humbuckers, because I don't like the sound of Mini humbuckers, but I kept them anyway. So all the people that are going to be swearing at me, saying, how dare you destroy a soft-roof range of tunes with other pickups. Yeah, shut up. I kept them, so I can always return it back to original. So, yeah, anyway, I'm going to plug this thing in, and now I will shut up. Alright, one thing I will mention as well before I play, this thing is warming up by the way. There is no negative feedback. So what does that mean to you? Okay, it doesn't feed part of the output back into the input 180 degrees out of phase to actually keep it clean. So it doesn't have that. So beyond a certain point, you actually get distortion, which is a really good thing. So what you want, this is why you play a valve amp in the first place, anyway, this thing. Should be warm by now, so I'm going to turn it up to about 1 o'clock. Strang away on the bridge pickup. Week, week is piss. You don't want that. You want to turn it up a bit more. 12 o'clock. Getting better, but due to the attenuation, I'm sort of losing a bit of tops. So I'm going to turn it up to about 2 o'clock. Nice, mild, heavy drive. Nick pickup. But where this thing really comes into effect is when you turn it up all the way, which you this now. Nick pickup. Alright, let's pause this for a while. When I come back, I'm going to have the range master plug into it. And then you can see how it really sounds when it's boosted. Alright, the range master is plugged in. It's bypassed at the moment. So I'll have it in the treble boost mode, which is the standard range master. But what I like best is when I flick the switch to mid boost, which gives a bit more flow. And then I split it up. I can do this all day, but I won't. So I'll leave you to it. And I'm sure there's other YouTube videos you can watch. As I said below, I'll leave a little link to the flicker gallery showing you how I fix this damn thing. Now I'll shut up. See ya.