 Hello everybody and welcome back to my video log, my channel, so I've been away for a little bit of a while. Oh, so many things to do, so many people to see, so many, you know, life can be complicated, can't it? So let's stop me dribbling on about this. Let's have a little look at what we're looking at today. So here is a kit on AliExpress, two pieces, the NAMNAP250. This is a kit that will be working between 15 and 40 volts and it is up 40 volts and 80 watts amplifier from what I can tell just by looking at the description across here. Now I've built these, well I've built one of them and I'm going to say straight away that it didn't have this capacitor that I'm sort of like over here, this 10 microfarad. It didn't have that, there's a canister on those. I'm electrolytic. But never mind, never mind, I expect these things change anyway. So let's have a quick look down here, what we've got a mod version, right, well mod version, I don't know if they're trying to get themselves away from the original NAMNAP250 by saying it's the mod version. I don't know. So let's have a look, see what it says. No, if you choose the order you need to solve it yourself, yeah. So NAMNAP250 mod version, mini circuit board, blah blah blah. AB works in AB mode instead of A mode, so it's going to be more efficient. Now it's got a THD and noise equals 0.01%. To be honest with you, I find that hard to believe. But look, take a look at it. And when we click there for product photos, they're going to be below. Looks like they've been doing some different bits and pieces with their website. Yeah, this is just a bunch of the close soundstage. I don't, you know, I mean, I expect there will be some good reviews, but I don't tend to go on reviews. So unfortunately, I found out with another big company that's very much similar to this, that reviews go up as soon as people buy things. They will say things, oh yeah, this is great, great. I can't wait for it to arrive and for me to build. Well, until it's arrived and you've built it and you've played with it and you know, come on, but that's the way things seem to work these days. I'm just going to show you just a quick circuit board diagram. Now I've not gone through this to see if this is exactly the way this particular circuit is, but it gives you something to have a little look at. And there's a bit of information out there. Now this is a proper NAMNAP 250. And this is the review on the website What Hi-Fi. And of course, it's going to get a very high rated review. And I would think for 5,700 British pounds or 8,999 American dollars or 13,500 Australian dollars, you'd expect it to sound nice. And all they want this one is to sound as good as the last one. So I just want to give you a little bit of a thing about NAMNAP. They've been around for a long time. They're very good. They're very well revered. And I really don't see you getting the same solid sound quality out of this. But hey, we're not here to judge. We're here just to check it out. That was me just knocking over my phone. It's my camera in this instance. And I might have to chop that bit out. Yeah, so, you know, that's the way that is. So let's go on with the tests. Have a quick look at the actual thing itself. And then we'll go on and do some tests. So this is the kit actually built up and put onto a heatsink. Remembering the input isolators behind these. They come with these rubber things. You can use those which are ideal. That's why they come in their kit. Or you can use the ones the way put in. Micah, which is what I tend to use early because I bought a big massive pack of them. Pack them up one stage because it was so cheap. So I figured I should use them. But I'll just use them here. It's just something that's worth pointing out. This is that these are all well and good. And it does make life easier, actually, not having to solder or, you know, screw on using these spade connectors. 63 mil these are. The one down here can be a bit tight fitting. But, you know, it all seems to go in there pretty good. That's a bit better than a wipe probably because my cat's been jumping over this. But everything seems to be okay. There we got that nice little thing underneath. That nice little, can't quite make it out of the eyes. Which way around that actually goes. There it is that way around. Always funny when they put those underneath there. And it's the same thing that JLM is it for lgm, lgm at foxmail.com. My eyes are not working at all today. Okay, we got the modified version. I don't know if that stops them getting its trouble with copyright or whether, you know, they just don't really care. So let's stick that on then and see what it looks like. See what it sounds like. No, I don't know. See how it responds on the test. We're going to be using this analog discovery too. 14 bit because I got it. I should use it really, right? So let me get it connected up. Simple enough. All of your grounds, including the dummy load ground, your power ground and your speaker ground, all go to this one. And then you've got your power negative. Because remember, this is positive and negative supply on to this. So you need a positive VCC plus VCC negative and the common ground, which is connecting a negative and positive together to make that a common ground. This gives us that swing. So we're going to just connect that up. And then this is our input positive negative. But I remember correctly, we've got positive and the negative input here. We're going to connect our waveform generated to there by our signaling. And we'll just see how it performs. It's using all the standard stuff that came with it. Some of this stuff is actually interchangeable. These transistors here. In actual fact, there's quite a lot of the stuff on it that you can interchange with other components if you want to. But we're not going to get into that right now. We're just going to set it up and just see how it performs in the mathematical way you know what we're going to get as an output reading. It's not a reflection particularly apart from the distortion meter. It's not a reflection really on the sound quality when we do the square wave. Because it doesn't work like that. Right, let's get it connected up and let's get it on the go. Okay, okay. Okay, that's that connected up. Looks a bit of a cluster mess. But you know, that's how we've got to do it. Now you can adjust the quiescent current on here, which I quite like. Let me just zoom in some reasonable. You can adjust the quiescent current on here with this little variable resistor, which is pretty good because I did find on one of the other kits I've built. It could rise a bit high, but you know, I could have probably changed that by putting the bigger heats in. So it didn't start doing this. I missed it as well. I need to find that bit of video maybe and show you. But anyway, so we can adjust that on there, which is pretty good. We can get it so once it's all warmed up and settled in, get it to where we want it to be. Now quiescent current and just let that settle there, put a bit of a little bit of something on there to stop it from moving with the, you know, with the various variations of temperature and movement, whatever. Right, let's start with the test. Let's get this set up for what we want. We want eight ohms. We want a doubt for that. All right guys, so we're back here. THD plus noise versus the frequency, right? THD plus noise, that's still on that one. Here's a good go. Channel one, THD nice, just checking everyone, the parameters are correct. 10 to 30 hertz. Let's go. Let's just hit run on that. Okay, well, that's, it's not the greatest we've seen. Okay, but this is incorporating noise as well. So what we can do is actually we can just filter out the noise. We can just look at the output of THD. All right, so that's filtered out the noise. If I put that back with the noise, without the noise. According to their specifications, this is supposed to begin down here, 0.01. And as we can see, it's not, you know, it's not exactly there. That's one of the highest points there. We've got a 0.18. You know, that's not, it's not terrible, but then it's not particularly great either. We'll do the power one afterwards. We'll look at the frequency response first. So you set this up, point channel and 0.2 in 50 steps on this. Let's give this a go on the frequency response and actually we're going to go 100 steps there and run. Yeah, I don't want that like that. I want this here and I want this here. Sorry, my bad because I want the zero here. So you can see it easier. And as we go up and down the scale, so let me just run that again. We're right there. Well, there's the frequency response. And we can see here, I know it's junction here, this is 20 hertz. Now, I wouldn't be bothered about that if it's, what would that be down there? That's there. We've got a 0.00 in this middle line, which is where we like to be all the way down here, nice and flat. At least I've seen better outputs. I'm not going to say I haven't. I've seen better outputs, but this does not look particularly bad at all. Even when we get to like the highest peak, let's say that's around about here, 0.10 DBR, sort of like up against reference input. All right. And that's that sort of like five, six, ten kilohertz and you worry about it too much. I don't know too bad. It's all really the look too bad at all. So let's have a look at this THD versus power. Now, remember we are eight ohms load. Let me just change that. We're on an eight ohms load. We are going to be running from one to 100 watts. THD noise, that's the settings that's there anyway. And we're going to stop at 1% THD, right? As soon as you get to 1%. I mean, it's 1% THD, you can hear it. It's quite a bit really, but you know, we're going to stop there. So we're just going to see what we can get from our 32 watts. Now I'm giving it the maximum current allowed and it'll only draw about like one and a half ounce anyway. This, but we'll give it a go. We'll run it from here eight ohms and let's just see what we get. Again, that's not too bad. If we look at the 0.1% line, that's nice down here and here's our 1% distortion and that's at 52.99 watts. If I just put it on the crossover, I prefer to put it there 52.99 watts. Yes, sorry. And when we're down here, you know, we're at 45 watts down here at 0.105. Round about here again, you can see again how it's like just risen up slightly here like it did on the frequency response. But that's not too bad. It's not too bad that type of output. Again, it's not the best. I've seen pretty sure I've seen, you know, a little bit better than that, but it doesn't make any difference. It doesn't make any difference. That's not too bad at all. What does that mean on sound quality? Well, not a lot really. It doesn't seem to particularly work like that. So now we're going to do a square low test, channel one. We're going to keep this level at 200 millivolts going in. RMS, of course, not peaked. We're going to use a 1000 hertz. We could do like 800 and 5k, 10k, but we're just going to use this 1000 hertz because it keeps everything nice and simple. And I'm just going to do a single hit on that. We'll just see what it shows us. All right, so that's our 1000 hertz. Now what I would say to me just like this is just, you know, there's hardly anything going on there. I wouldn't even be too bothered about it whatsoever. We're just going to go down to, let's say, 500 hertz. We'll have a quick little peek at that single. Yeah. Again, you know, there's hardly anything there. Nothing really worth writing home about. Hardly anything there. Let's drop it down now to 50. We should see a difference on this. Just hit on the single. All right. All right, we see some drop off now. This, I mean, again, not too bad really. It's just that is bass drop off, but it's not too bad. I mean, it's not as low as down here, but it's certainly not down here. Just, let's have a little quick look on that 20 hertz because to be honest with you, for most people, when they bother going down less than 60 hertz, just because your speakers are probably not going to be able to represent that anyway. Of course, some of yous out there will have speakers that can represent that and what other chances are you're not playing around with these little tiny kids. You know, it's all right then. And what we did see, actually, there was a little bit of a loss, wasn't there, on the frequency response. Let's just have a quick look back at that because that will still be there. And we can see our 20 hertz. See the drop off there? And we can actually scale it to there. We can say our 20 hertz, we got a 0.11 dB drop off compared to the reference going in. All right, so it's hardly anything. So I'd say that it's looking all right. It's looking all right. Let's just go up the scale a little bit then. Let's go to, let's say, 5, 0, 0. So we're at 5K now. Do a single shot. Yeah, lovely. Yeah, nothing wrong with that. Let's go straight to, let's say, 15. Is it on a single? Again, not really that bad. Yes, there's a little tiny bit of, you know, it's losing its rise time. But hey, you've got to be able to measure this as well. And I've got to be able to put that into it. And I'm not sure if this is capable of shoving it in so we don't lose any of that rise time now. But let's just do another one at, let's say, 25 just to go for the extreme. This, look at it as a single. Yeah. So being honest with you, that's not too bad. Now the test will be, of course, the sound. But I'm going to say this now about doing these sort of sound tests is the whole thing about doing these sound tests is it is all well and good for me sat here with my little setup. Let me just get this going on this. Yeah. So it's all well and good. Me sat here, you know, with my little setup with my speaker up there and that one there so then they're not even matched anyway. And it will sound okay. You already can, you know, put them over to the speakers here. These floor sound is these monitor audios. And I'm sure that it's not going to sound too bad at all because it doesn't seem to come up as any big problem on anything. So I'm going to go out on a limb and just say, I don't think it's too bad. Just what it's given out here is not too bad. But this is not going to tell you about sound quality. You know, the outputs on this will not tell you cannot determine to you what that sound quality is going to be like because a lot of times the sound quality with these things is a personal thing. It's your personal preference, how you like to hear the stuff. So I can tell you now that the actual amp that I'm running at the moment is the L12-2. That's what I've been using at the moment to listen to that. And I can tell you that just moving my speakers around to get them closer, a little bit wider, a little bit too far away, a little bit closer, for my personal preference, it's my personal preference. And so you're all going to have that. And because I've not run the L12 on these little speakers, I've got to put my bench here again. On these ones, I've been running down on either, it's going to sound different. And that's all going to be down to your personal taste. That's all subjective. It's all going to be down to your personal taste. So we'll have to just see. And if you can, if you can see over here, we can have a little look and see the quiescent current over there. When it's just sat there with no input really, it's all on, but no input. You can get to see what's going on there. So if it was at high voltage, let's say there was 40 volts on there, it would probably be more like 46, maybe even 50. That's fine as well. Okay. Well, that's, that's it for this. The next thing will be the sound test. And I will do it, but trying to feed you that, trying to give you that all I can tell you is what I think. I can't really put it across your well enough. I've got nothing here that will pick this up and get it to you. So you can hear it out of your system, your side. I don't know what you're using. If you're listening through a phone or laptop or a high five system, whatever. I can't do that for you. And to me, it just seems it seems a little bit unfair to try and say, yeah, it sounds great here. But I'll tell you now, if I remember my speakers, it's going to sound slightly different to me. Yeah. So where do I put them to tell you how it sounds? All I can let you know is no, there's no distortion. No, there's no popping as you're powering up and powering off or whatever, you know, sound description that noise makes. Yeah. So there we go. Anyway, guys, I think this has been way too long on the on me getting there and giving it to you. Like this and it will be in a few days, maybe four days, I'll do the old 12. All right, which I know there's quite a few people have asked me about the old 12. What do I think of the old 12 and all that. And and I'll give you a, you know, I'll give you the rundown of that in the next few days. All right, guys. Hey, if you tuned in, you got this far, thanks for watching. Give me a feedback if there's any other way that you think I can test this, that you think without having to go and buy equipment and do bits and pieces with the kit that I got here that I haven't shown you just let me know and I'll try and fit in the little shorts or something and do that for you. So the next one, take it easy. You're all safe and everything and speaking soon. Bye for now.