 Hello everybody, welcome back to my V-log, to my channel, there's another audio amplifier circuit, or kit, and this one is a Iyama 2 pieces MX50 SE 100 watts x 2 dual channels audio power amplifier board. I'm just reading the description from the page, I just chucked that page up there for you quick, so you can have a look. So there's a whole bunch of components here, there is for two channels, so the individual channels, which is nice, I'm only going to build up the one, I do like the, I do like that on there, it's pretty cool, pretty cute. Well, what's that say, there you go, information there, information on there, oh, what's that say about the gain, so you can adjust the gain, 22, put a 470 arboon, or a 330, a 31 gain. Alright, that's pretty good, the voltage is, alright, so that's interesting, that's on the board. So we've got some heatsinks here, all sorts of chips here, this is KTDs, these are Korean jubbys, the main output chips, 10, 47 may look familiar, but I don't think it's the same. I'll stick a thing up on the screen for it, we've got a whole bunch of the same resistors, which is nice, then I've loads and loads of different values, I can just do a one-value one here, I don't know what the rest are. That's why it's good to have the old meter in the background there, and we've got some more, I believe the transistors, I'm not sure we'll have to look them up, what we've got, what's that? That is, for anybody who's taking notice, that's probably the same thing, can't all be the same, well, and my, my, my, are they alright there? There we go, and you get all the screws and some terminal for some spade connector female jobbies to go over there, so the capacitors here are, that says it's a Rubicon, which is quite nice, we do like Rubicon, and what we've got here, we've got MXB Sam Young, 15 ohm jobbie, 100 microfarad, and I presume the rest of these are going to be the same, I wonder if that was, well, it really seems like there's been one Rubicon so far, oh no, this could be a Rubicon, yeah, we've got another Rubicon, these are 470 microfarads at 16 volts, and it's quite nice, we've got some nice little, these 0.1 ohm 5 watt resistors, they're going to get by the power output, and some other, you know, some metalised capacitors and such, and bigger in there, I presume, let's have a look at this, what's that? 334, what's that? 33? No, no, no, got the micro, but sure, yeah, let's have a stick this on there, so I can get a new one that is in the background, 3.4, so that's probably the input there, let's have a look, yeah, 3.3 microfarad, okay, so that's our input, probably, yeah, from the positive to one side of that, alright, you heard then, so what we're going to do then is, there's some, looks like one watts resistors, we've got our bits here, the insulators and that for the transistors, that's nice, it doesn't look like, looks like there's just 4 insulators, so these ones here, I suppose the case is, no, yeah, it's looking at the back, because I don't have any metal, so you don't need to insulate them from here, and this has got this black stuff on anyway, so you should still, probably put insulators on if you need them, if you've got metal backs, but these ones don't have, so that's okay. Alright then, right, I'm going to build up one of their channels, I'm not going to build them both up right now, and we're going to test it, and just see what it's like in there, go from there, alright? I'll build it up off camera, because it just means I can just pot it around it in the end time, and get back to you. Alright guys, so here it is built up, I've got it on a heat sink already, everything's in there, correct? I put these, I didn't have any of these connectors, so what I did was go through my old box of cables and found some of the connectors, and so here it is, you've got it on the heat sink, and it's looking good, get it nice and clean. I don't know what it is, is it an owl, is it a panda bear, is it? I'm not sure what it is. But okay, so that's ready to go then, and what we're going to do is we're going to get it tipped up to our inputs here, so this is our main input, this is going from the wave generator, and then we've got our power and our atome output, so we've got a ground here that does for everything, and then we've got our output here for the audio, and we have, and then this bunch of wires, if I get this right, if I put this out to this now, here a bunch of wires from the power supply, so I'm going to use the power supply, and on this side it should be black, means that we've got, again, onto the ground, and we're going to have our red and black the other way round, I do believe that that's going to be in there, and that's going to be there, I will do a quick little check, because it's always good to just make sure that's VCC+, and it does, alright then, so that's why I just showed you it without the wires there, because this is a bit of a mess, we'll pop on our power supply, now we're going to be using the waveforms with this, with the analog discovery 2, because it's a 14 bit, and it works really well with audio, I do like that, now the first thing I'm going to do is, just quick check again, I'm going to the power supply required for this, and I do believe it's plus minus 15 to plus minus 45, and it says the output power is 100 watts at 8 ohms at plus minus 42 volts, and there should be a quiescent current of approximately 30 milliamps, now there's no way of adjusting the quiescent current on this, there's no variable resistor, so that suggests to me that the quiescent current is fixed, and if it's 30 milliamp, and you've got that big old voltage range, as the voltage goes up and temperature goes up, the quiescent current will rise, and it will rise, especially with the voltage going up, so I'm not quite sure, well I thought I would peek at that, and it's easy enough for us to look at it, because we can just look over here, and see what current's being used when this is on, so let me just, I'm just going to put this into this tracking mode, alright so that's enabled, and we're on 15 volts already on this thing, so that's good enough, we'll start off with 15 volts, and while we do that actually, let's just have a little look at the quiescent current there, and let me just put it in closer so you can see, we'll just look at the amperage, and this is for one channel, so combined we've got like 40 milliamp quiescent current, and that's at 15 volts, now if I start turning the voltage up just to, just put it across there, 105, let's say we're going to go for the 30, yeah 32, now we can see that that quiescent current is going up, right, but not on 30 milliamps, I'm just going up, and we're going up, we're going up, so it reckons 42 volts, it can do up to, or 45 volts, and as you can see the quiescent current would be going, rising, rising, rising, I'm going to turn that down, I don't like the idea that it's going to go up that high anyway, let's have a look, 25 volts, so it just stabilizes out a little bit, alright we'll call that stable 25 volts, let's just say if it's 24 volts it'll probably be even better, okay let me just back that out again, okay guys so I just wanted to do a quick little what I meant by the quiescent current will change with temperature as well, so there's no input going into this at the moment, we're just going to power it on, and what we're going to notice is that the quiescent current there will rise, as this warms up it'll rise, and obviously it's not going to rise as much as what it would regarding voltage, but nevertheless with temperature this will still rise, and of course we wanted to understand whether it was any good for you know the 42 volts range getting straight in there, you know we can obviously see that that's not going to stick to 30 mA, anyway that's it, it's rising and that's what I wanted to show, so let's, I'm going to leave that there, because we're going to start these tests now, and first of all, we'll just get this going on the waveforms, and we are at, on here we've got 5 volts per division, 5, 10, 15, 25, yep, there's channel 2, just ignore that, we're really doing channel 1 here, and we've got a time base of 5 mA, we're going to put that down to 500 so we can see the nice sinusoidal curve, and we're going to switch this on now, and just start going up, on the input there, and so we can see we've got a peak to peak of 30 volts, and we keep going up, keep going up, keep going up, so we want to just push it to where it starts clipping, and I think I saw it clipping top and bottom nice and symmetrically, it's going to back that off to around about there, and we'll just change the time base of this so it looks a bit more easier to read, now by the looks of this, it looks like there's some distortion there anyway, so let's just turn this down a little tiny bit, so we get that so it looks reasonably nice, we turn it all the way down there like that's no good, but that's too much, so let's just, let's just so we can push it to about there, and have a quick little look at that again just to make sure it's not doing anything dodgy, look at it here, now it looks present enough, that looks okay, let's make anything wrong with that, I'm going to put that like that, and so that's what we've got, so what I'm going to do then is I'm just going to stop that there, stop that there, we can see that we've got a 765 millivolt input going into that, and we can see what was going on with the current mirror, let's just look across here, so these are all the 65 down, so there's no way you're going to hear any of this, this is just the other harmonics, it's nothing bad, nice, low noise floor in general, it's alright, so you know, I can't say this is bad at all, now I'm not going to bother doing a sweep on here, what I am going to do is we'll just stick on the other, but a software which is the Audio Analyzer, for that we want to go into Windows, okay guys, so we've got the Audio Analyzer software, so we're set up here, 10 hertz, 20,000 hertz, bandwidth 50k, and we're going to go out of 5 watts 8 times, and we're just going to look at it like that, 5 watts because we don't want too much noise to be in there by being, you know, really low, 1 watt you can have a big noise to signal, okay, so there we are, 1720 kilohertz, 0.1, we've got a little bit of a spike there, but I say 0.14, and all this stays with me, nice, now I'm just going to quickly do this again at 10 watts, and just to see what the difference is going to be, alright, just before I do that, let's just check out first of all, get rid of the noise out of the signal, and there you go, that looks a lot more, a lot more tame, 20 hertz, not 0.05, alright, that's at 20 hertz, now my speakers aren't going to be able to do anything with this until we get to 30, 34 hertz, so back here we've got 0.04, that's beautiful, now it's just going on my speakers, you know, so that's absolutely great, so I'm going to put the noise back in again, and I'm just going to go for this at 10 watts, okay, that's our 10 watts, and again, that looks lovely, 20 hertz, not 0.09, I've got a peak here, 0.12, there we get rid of the noise, and we look at that again, and that's lovely, 0.07, our peak here now is around about 0.06, lovely, can't really complain with that, can't really complain at all, let's switch it over to this, and we're going to go from 1 to 100 watts, we're going to allow for 1% distortion, where it will switch itself off, and we'll see what we get out of this, then we've got 25 volts going in, besides the negative, positive 25 volts, okay, that's lovely, I mean, look at this, so if you're creating music again, we're at 25 watts here, between 25 and 30 watts, where I go there, you're at 0.04, in this area, lovely, and so we can get 30 watts out of that voltage, and you've got 33 there before you get to, that's at 0.5%, and the 1% there is 34 watts, 33.2 there, so that's nice, a quick look at the frequency response, here we're going to put a level in of 0.3, 0.4, let's just go 0.4, and channel 1, and run that, what can I say, very nice, that is very nice, that's from our 20 hertz there, and there's, even from this at 10 hertz, which really we're not, but the 30 hertz is very decent audio range, and the difference between this and this here is 0.02 there, we put that back to the 20 there, 0.08, and we go 0 minus 0.16, 0.0940, it's at 30 ish, 20, yeah, nothing really to report, that's very nice, that's very nice, so alright, well I'm going to say then, just let's back out of that for a second, come back to this, that's a winner, that's a winner, winner chicken dinner, and I'll tell you for why, because that was 13 pounds for shipping, and I'll tell you a quick little tip, the reason why I would go for the free shipping and everything, is because everything I buy off AliExpress and lots of other places I get 10% back, 10% cash back, alright, there's the UK guys, I'm not sure what it would be in the United States or around the world, sorry, but for the UK guys, completesavings.co.uk and you can do RS components, Farn Aliacan, AliExpress, Banggood, there's a whole bunch of them out there, and you can get 10% back on everything, so that's the way I look at it every time I think, alright, £13.88, I get £1.38 back, but it's £1.38, you don't get it back on shipping and you don't get it back on taxes either, so if you find stuff and it's always like, then they say it's like, yeah, £1 for the amplifier, but £30 for shipping, you're not going to get anything back really, but for this sort of thing, it's all good, right, that's it for that guys, that's it for me, big thumbs up this one and I'll catch you in the next one, bye for now.