00:07Hello everybody and welcome back and today we're still looking at this NAMM circuit the
00:14NAC52SE fully discrete pre-amplifier DIY kit finish board now I've been playing around with
00:23this using the audio analyzer I'm just gonna show you real quick just it's all simple enough to
00:31connect up I've put there a couple of these blue connectors on and I've still got a blue connector
00:35they're just be playing around and I've got it wired up at the moment to the digital the analog
00:44discovery tube just because it's just easier for me to set up like this to be honest with you at
00:51the
00:51moment so let's go back to the screen and we'll look at the audio analyzer speed here and I've
00:58already run these tests I'm just going to show you very quickly what we got here is range 20 Hertz
01:0430
01:04kilohertz we got a total harmonic distortion plus the noise on this so you can see here if we look
01:11uh we're coming in at 21 uh kilohertz or just there 20 20 Hertz sorry um and over here we've
01:20got 0.07 if
01:22I just put that back there across here 0.07 so I'll just run across it quick so we get
01:28to a
01:290.078 there 0.05 0.05 0.05 0.05 0.05 0.05 0.06 0.07 0
01:39.07 0.06 0.05 0.05 0.05 0.06 and that's that 27.86
01:54kHz. So that doesn't work too bad at all. We don't do a tight alarm and extortion of
02:01power with this. We'll look at the frequency response. I don't mind running this again
02:06just because we're here. I'm going to put it in a slightly higher level actually and
02:13just see what happens here. I'll run that. Yeah it doesn't seem to be too bad at all.
02:25This is 20 Hz. We've got a 0.09 difference in reference voltage. We're pretty
02:34much a straight line across and there's a slight gain there of 0.09. So we've got a
02:42gain of 0.09 there. When we get to 20 kHz there, 20 kHz. We've got a little minus 1
02:51.7.
02:52To be honest with you, that's not particularly bad, especially for one of these kits. If you
02:57remember, we just look at the price, going quick, £6.70. That's for me logged in so I
03:02don't get any special discounts or anything but you can get a little bit
03:05cheaper a lot of the time. So yeah, not bad. Spectrum Analyzer. This is roughly about
03:14its sort of sweet-ish spot. I can keep playing around with it and get these to be a bit
03:20different.
03:21Put it on full volume, I get a bit more here and this drops down here. In actual fact, the
03:262k
03:27drops down remarkably well. But this is sort of like the sweet spot from what you're getting.
03:32to keep those numbers round about the same. Minus, let's just go back here on that third
03:38harmonic because that's the one that's near enough sticking out the most. And you can see
03:42look at minus 74 dB at the 3kHz. And at the 5kHz, look over at the same place, minus 73.
03:51Not bad.
03:52All sort of ties up with those numbers. Looking at the scope side of things, this is at 30Hz.
03:58It's not really a great deal of drop-off there. It's not perfect, but then you wouldn't really
04:03expect it for this sort of thing. And I'm going to just try this again with these levels here.
04:10Paste that in there, just in a single shot. I just wonder if this makes any difference.
04:14That actually drops down to a slightly higher power level. It seems to be happier for the bottom end,
04:21which I suppose is about right. So if you see that jumps, yep, yep. So it sort of jumped up
04:26a little
04:26bit and made it a bit squarer there. But if that's at 30Hz, we'll look at 20 just for the
04:33sake of it.
04:33100. And do a single shot there. 500. And do a single there. That's nice. That's a very
04:47nice square wave actually. We'll go to 1kHz, just for the sake of the 1kHz thing.
04:56A single shot there again. Very nice. We'll just jump straight to 10kHz now. 10kHz. Yes, slightly a little bit.
05:08Could be a speed issue, not sure. We're going to go to 20kHz. And still, that's not too bad. I
05:19mean,
05:19it sits nice and tight like that. It's not too bad. I know some people got really high on these.
05:26And I'm going to get a 50kHz, just for the sake of it. Just have a look. Nah, not that
05:32great.
05:33Back it back down to 30kHz. Ah, it's very acceptable. Very acceptable. So, just going back here again,
05:43very, very quickly. So this is when I was just looking at some NAD amplifiers actually. I don't know if
05:48it'll still be in my thing here now in the end. Is it? No, but I was looking at some
05:55NAD amplifiers.
05:57And I was just wondering, um, well, I was just wondering what the, um, the THD because a lot of
06:07the
06:07time it, um, I'll put it in here now. Uh, is it in there at all? No. So, NAD amplifiers.
06:20So here we go.
06:21This is what I was looking at. So we got the, uh, the 3020 because that was a classic, wasn't
06:26it? And this
06:26is now a hybrid digital. Uh, what I was looking at here was the specifications. Uh, when you see here,
06:32look, um, um, at the total harmonic distortion, I mean, it is a very good number, but then,
06:40you know, if you put the five here, you put the five there and that's, that's, it's only one order
06:48of magnitude out from what this little tiny, you know, this will be screened up and all sorts.
06:57Um, but for what this little tiny, uh, this little tiny kit is offering and that's with noise. And
07:03that's something I need to point out now because look, there's no 0.05, right? That's with the noise.
07:09And now look at this look, total harmonic distortion, not with a noise. It doesn't say noise as well.
07:16So let's just go back here and we'll filter out that noise. Boom. All right. It hasn't dropped down
07:23drastically, but it's still, uh, 0.03s now. All along the line, 0.03, 0.03, 0.03, 0.01,
07:350.02.
07:38We're above 20kHz now, 0.02. So you just take out that little bit of noise and look at the
07:44second
07:44harmonic, uh, 0.011, you know, 0.014, 0.08. So I'm going to say, look, this little tiny,
07:54for this little tiny board that we've got here for the amount that it costs. And if you're a newbie
07:59to AliExpress, you get it less than half the price. It seems like it should be okay.
08:06Nothing to say in the outputs. It's going to be terrible.
08:12And it's all going to be down to preference of choice because I tell you what, right,
08:15I've listened to so many of these now and I've listened to so many of these little amplifiers
08:19and it, look, you go read up on the square wave thing. Square wave will show you, yeah,
08:25okay, brilliant. It does a great square wave going through. That does not mean to say it's
08:29going to be the quality of sound because that's going to be subjective. Right. I'm going to give
08:35you this in the starkest way possible. The subjective quality of sound is my daughter, when she
08:40was a baby, her crying to me was like, you know, she's singing to me. She wants something. So
08:46what it doesn't matter what it is, I'm going to go and attend to her. She's my baby.
08:51But somebody else could just sound like a squawking child. You see what I mean about sound is
08:57subjective. So you spend, you know, you'd hope if you went out and spent 5,000 pounds on an amplifier,
09:05and then you stuck it next to a board you can get off Aliexpress for 50 quid. You want it
09:10to sound better.
09:12You want it to sound better. And chances are to you it's going to sound better, whether it does or
09:16doesn't.
09:17To the next person is a different thing. So it's one of those. It's a cheap little board.
09:23It doesn't seem to have any issues with it whatsoever. And you're only going to know
09:29whether you like it until you listen to it. All right, that's it. I'll catch you in the next one,
09:36guys. Take care for now. Bye bye.
