Hi, its teardown time I was contacted by you whatever you want to call them awhile back and they said hey, we've got these newfangled Bluetooth grown electrostatic speakers. Do you want a review on us like me? Not really, You know. hey, if you if you want, send it into the mailbag and I might do a quick two minutes here down but with the recent electrostatic whiteboard video which I've done, they are linked in down below and at the end if you haven't seen it. I Thought this might make an interesting follow up to look at how an electrostatic loudspeaker is built cuz these are like electrostatic loudspeakers.

A lot of the audio files rave about electrostatic loudspeakers and how they are totally different to voice coil loudspeakers. So I thought it could be interesting to take a look at these things. They're not very common these days, but obviously they're jumping on the wanky bandwagon and they've got these new bluetooth consumer thing. Anyway, let's check it out, shall we? Hey, I'm not I Don't care if this will not be a review of the speakers I Just like I just don't care about like a Bluetooth speaker thing.

Anyway, even though I did have a recent mailbag video which I haven't shot yet, these are audio Smile Bluetooth speakers they're these are a Kickstarter do-it-yourself I might do a quick teardown on those ones anyway. that'll be a separate video so let's have a look at this. Trevor Lo S series Okay, supposed to be newfangled, but they use the electrostatic principle which is interesting because I Thought like the only Electra steak speakers I've sort of known of them. That's it.

I've got one. Oh, it's one speaker I assumed it was multiple speakers. it's unless he hits one speaker. Go figure.

Anyway, summon no miss stereo rubbish. and that's well. that's surprising. that's that's surprisingly hefty.

I Do wow I Do like that. Our gold. Ah thank you very much the gold. Look at that.

Wang Curry Excellent. That actually feels like really nice quality. It looks like they got to regular voice coil drivers in the front, but that's oh oh, it's wings. it's gone.

There's your stereo. There you go. these electrostatic panels. that's actually really.

that's actually really quite funky. So I assume maybe they've got the the voice coil drivers your traditional ones for a bit of bass like a lower-end I'm not sure the frequency response I don't know the details. Anyway, a couple of red everything's who cares. I'm interested.

Sure it sounds okay, but I'm interested in looking at the construction of the electrostatic speakers I Think this may be a destructive teardown. Oh Beautiful. So I got to admit I Really am impressed by the build quality of this thing. It really feels like a solid bit of kit.

We've got a metal case here. we've got the passive dissipators on the side. It's not your traditional ported bass enclosure because these are the base drivers on the front here. and I don't know it doesn't actually specify like what the crossover frequency is, what the range of the electrostatic parts are.

So yeah, we don't really get that sort of detail anyway. Does feel like a real high-quality bit a kid I am very impressed. It's got NFC in it to help with bluetooth pairing and all that sort of stuff. It's got various wanky modes and things like that and you just hold it down and it powers on.

As I said, it is actually a little loop. It is actually battery-powered microUSB probably should have been USB see these days I Guess our 3.5 millimeter Terrace audio input jack if you want to use it that way and fabric in Cheney Does it actually come out the back as well? because they've got the same grill on the back so I'm not sure. Anyway, let's get into it. look so I got some screws under there and we've got Torx screws now this Philips rubbish.

Philips Get it because Philips make audio Geir I'm here all week and they've got like a vibration absorption foot on this thing so you know that's a nice tension to detail. They've tried their Mac you know it's not going to be hugely effective given the you know the thickness of that. but anyway, nice touch. Ha.

That was tricky. kind of had to prise it. open it it anyway. it finally came off.

Tada, we're in like Flynn Check it out is our passive radiator. Look at that. we've got one on either side because this is not your traditional tuned port enclosure. because these are our woofers down here.

We've got dual one. so probably because you can't put a large diameter in here. of course because how slim it is. Therefore, you can't move as much volume with one cone.

So that's probably why they put two in there to move extra volume. And so instead of having a ported enclosure, they have these and this is like a focal. Do a similar thing. not with my ones, but with some of their high-end studio monitors and things like that instead of having a tuned port enclosure.

I Won't pretend to know all the pros and cons of that. you can fight that out in the comments yourself. But anyway, that is a real nice bit of engineering. I'm very, very impressed by the envelope and form factor and build quality of this thing.

It's excellent. We've got one main board here. looks like we've got another board on the front for all the front panel switches and a couple of leads. Probably for note, near-field antenna is actually it's right there where the cymbal is, which is how it's supposed to be, but everything's all on this one.

Boyd Someone got our two batteries down the bottom. they look like 218 650 s got some battery and charge management happening on the back board and with the USB interface of it yet, they've got a board to board interconnect down in there. They've even gone to the effort to put these little foam pads in here, so when you close that again goes like it closes with a nice soft sort of you know, dull thought instead of our whack. And that's an analog devices SSM 3582 and that's a Class D amplifier.

35 What job? And well, yeah, that's all there is to the driving this thing. Perfectly adequate. Nice part for the job, so no worries there whatsoever. As for the rest of the board here, not much else doing.

just got a whole bunch of passes. Of course there's going to be some more processing under here because it's got a you know, a DSP type magical algorithm thing in there. of course. Where's wally? This is an electrostatic speaker, so it's got to have some sort of high voltage drive.

and bingo, lift the skirt there. and we found ourselves there's a high voltage transformer. There's two of them here now. I'll put up a typical diagram of how an electrostatic speaker actually works and you know really, if that's how they're doing it with the center tap of the transformer there.

So the sent yet senator taps going off the ground and this is going like this is coming from here. So this is going off to the speaker looks like speakers either side. There is it. and we'll have to flip the board over to see on the other side anyway as two of those transformers in there.

one for each electrostatic speaker. no really. like you take the screws off, then you pull it out, that board to board interconnect there and they got tape everywhere on these things holding down all the cables to. That's a very nice attention to detail.

This thing just oozes build quality. It really does. There's our extra processor and that's where all the magic happens. It's a Csr 86 70 from Qualcomm and this is like a He Bluetooth space application specific process in DSP Chip has a DSP core in a whole bunch of other stuff.

incredibly powerful, purpose designed ASIC chips. so yeah, no wonder they are using that does all the magic. Runs at like 80 megahertz. DSP You can see the little oscillator over there.

You can see a whole bunch of miscellaneous stuff there don't actually have access to a data sheet for that's probably one of those stupid, you know, proprietary things. You'll assign an NDA to get it something like that. I Love the SMT arrow on here as if this is going through a wave soldering machine. This is not.

This would be double sided reflow. So I'm not sure why they have the directional arrow on there so it's strange. and if you thought that Qualcomm DSP Did everything look at this special purpose chip from a company called Quick Filter and it's the through. F 3d FX Psycho Acoustic Processor.

You have a hard time finding a more sort of like a specific chip than this one that it does. As its name suggests, it does all sorts of acoustic effects for like you know, passive radiators and you know a quasi surround sound and all that sort of stuff for you. seen like TV sound bars and you know all those sort of things. So perfect for something like this.

So not only do we have you know that doing its business, but of course the you know the special purpose DSP over here. so this has lots of like you know digital processing magic in it. oh he's our Transformers. let's take a look at those.

Okay, I'm not sure if you can see that I don't know where my macro lens is and my microscopes aren't set up your head. sorry, but that's an AKM at Seven Double to AKM Semiconductor make lots of special-purpose like you know, audio chips and Dax and all that sort of stuff and we've got two of those jobs there and they're going out. They're driving the Transformers there as you can see so I can't actually find any data on that. The Seven Double - I can't find a match at a Km Semiconductor.

So I yeah, I'm not sure whether or not that's some special codes, so it's a power amplifier drive a thing that's a tiny little pissant chip. Look, what a pain in the arse package. Unbelievable and you'll notice the fully sealed enclosure here. They've got these little they like little rubber hard rubber plugs in there to actually seal this up because is, as I said, it's not a tuned port enclosure.

It's completely sealed in closer enclosure with these passive radiators. There's so I don't really care about the other boards in here, like the charging board and stuff like that. I You know really all of the magics are happening on here, so from the circuitry point of view, that's really all we care about. And of course you know.

Plus, the amplification. Incredibly efficient. which is why you know we don't even need any like backside PCB heat sink or anything like that. You know, thermal vias going down or anything like that.

So incredibly efficient. This is like, you know, a 30 odd watt speaker, but that doesn't waste much at all. And inside there, there's nothing exciting happening. There's no acoustic material or something like that.

They've got like what looks like a fairly long throw woofer down in there and one of those long strollers. You can get fur in like what inch and a half diameter? something like that. So and that's just the passive radiator like that. I Mean you'll probably never see a go thump-thump-thump like that, but it does have a fair amount of travel Look at that.

Anyway, they're designed to like, just passively radiate that out. and I won't pretend to know the advantages of that over a tuned port enclosure or the speaker designers out there can fight it out. In the comments, let's actually have a quick listen and compare them to mate with my Vocal Professional Studio monitors here: CMS 40 Die cast alloy enclosure. These things are sex on a stick.

Let me tell you. Oh ironically play my own intro video Trevor Low speaker? Yep, let's go and then I'll switch it hi, it's teardown time I Was contacted by you whatever you want to call them and now the focal CMS 48-hour time I Was contacted by thank you whatever you want to call them a while back and they said hey, we've got these newfangled Bluetooth grown back to the Treble oh it's Daddy Totally lacks the base of the vocals, but that's to be expected of course, given the minimal drivers we've got in there, but yeah, it sounds a bit hollow, but it's actually pretty good. It articulates speech fairly well us. But now this is interesting.

Listen to this different device with the speakers out like this: I Thought it could be interesting to take a look at these things. They're not very common these days, but obviously they're jumping on the wanky bandwagon and they've got these new bluetooth consumer and I fold the tweeters in the electrostatic panels I Don't care. This will not be a review Djem out of the high-end detail at all. Anyway, Okay, what I've done is actually disconnect the electrostatic tweeters on the side here.

I Call them tweeters I'm not sure how full range there, so let's actually play it: Electrostatic speakers. Do you want to review a mess like me? Not really. You know, yeah, if you want, send it into the mail, but so it's a bit muted. Yeah, you can equate the high-frequency stuff is a bit muted, but let's play The Weird Al But it does seem that these drivers on the front here actually have like kind of your traditional crossover frequency of your studio monitors because I've disconnected the tweeters from my studio monitors and you get that sort of like it sounds like a coupla kilohertz sort of bandwidth.

So the electrostatics are definitely doing the high-end now. I Tried to pair it up without these drivers the main drivers, but it just wouldn't pair up. So I don't know. It might have some sort of, you know, broken coil detection or something like that.

It just it just wouldn't boot. Strange, but there you go. I Disconnected the woofers after I booted up and that's a response. Jesus Not much coming out of those electrostatics.

Haven't adjusted the volume at all in that aspect. Yeah, the electrostatics seemed to be doing you traditional tweeter function like you getting regular two-way speakers. Now the interesting thing about what we just heard is I'm not sure how it's possible because I had the case off and look at the of course you need three wires going to the electrostatic speaker and you can see the three wires going in there. Two of them of course come from up here, which comes from the main board that's from the output of the audio transformer here which isolates the high voltage.

The third one is just going over to this which goes over to the case. and sure enough, you have a look at the case. They've removed the powder coating on there. So those two wires are supposed to go to your two outer grids in your electrostatic speaker.

and the third wire is supposed is the high-voltage one which goes to the diaphragm which is supposed to be sandwiched in them in the middle. That's assuming that this is you know, your traditional construction electrostatic speaker. so we've got no electrical connection to that. So how's it working? Um Bua Bua In fact, I don't see any high-voltage generation at all.

Orcas Look if you once again, if you compare it with your traditional, like standard electrostatic implementation. Okay, we've got a high-voltage isolation transformer. The center tap of our output is negative which is connected down to our circuit ground here. No problems whatsoever.

But then we're supposed to have a high voltage generation on the other end of that which is down here. So this is supposed to generate. This is supposed to be connected to the positive of our HV source, but you can see it's physically electrically connected to the case. So what? I mean there's just nothing on there.

There's no Cockroft Walton multiplied like a high voltage multiplier as I've done a separate video on. So the only way that this can work is if they flip it around and instead of having a high voltage generator, they actually use the transformer itself as a high voltage step up. So I suspect that we're going to see a large turn ratio from the primary to the secondary. So I'm gonna have owns over here and we might have hundreds of ohms or even kilo ohms on the secondary side of it and then that centre tap of the transformer on the secondary side that's connected to ground of course.

So then you don't need any high voltage generator, you're actually using the transformer to boost the amplitude of the signal going to the to outer. so the differential going to the two outer grids is your high voltage and then go into your diaphragm in the middle. So let's have a look. So this is the primary side and yep, 1.1 Ohms, No workers.

Jeez, that's low so you know. And they it's a grunty little, that grunty little driver that they're using there. that little ball grid array, tiny thing. and the secondary.

expect at least Aa one point. there you go. one-and-a-half K So yeah, they're stepping up that like a thousand times. So out of one volt drive level just as an example, you'll get a thousand volts differential drive across your electrostatic well across you to grids as a differential and then they're just using.

The diaphragm is connected to ground so they've just inverted the topology. So to speak of your regular electrostatic implementation that it works room those you want to see the other side of the charger board, there it is the case. ground is connected to the Usb ground here. so and we're getting further into it now.

you can see there's a little NFC antenna up there. You can see that there's nothing on there that's just got the switches and a couple of LEDs and that's all she wrote. That's all. Feridun Nicely integrated and designed.

I Really like it. Very impressed by the design and construction of this thing. Hats off to the team that did that, and for all you driver aficionados there you go. There's a fair bit of throwing that isn't there.

Don't mind that everyone's horrified now that I'm poking it. No, if you're wondering where that coax come in from the DSP chips it, there was going off to wow I know you were there. It is there. so that's your bluetooth on the top.

Beauty. All right. I Was thinking that we might have to unscrew or that, but it looks like not. It's just clipped in the back there.

I've got some felt. let's lift that off. Aha bloody tape. There we go.

Oh look okay. cross pattern thing happening here? Your that? You can see the mesh? Well, it's fascinating. and we've got some sort of cross pattern happening inside here. Definitely.

We're almost certainly going to have the same thing happening on the other side here. undoubtedly. Yep, an identical screen on the back there. Uh-huh There's our connection so it doesn't looks like it on it.

Maybe it only goes to here. Doesn't go all the way with LBJ right over to here. Okay, just took the little full little screws out there. So in the traditional topology, you expect one of the terminals to go off to the bottom plate, one to go off to the top plate, and the third connection going through to the screen in the middle.

Ah, there we go. So it's all sandwiched together so it looks like I'm gonna have to either peel off that tape or cut right through it to get into there. but you can certainly see the the cross patterns on there. That's interesting.

Don't know why they needed to do that. Sure enough, that's exactly what we see. One connection to the top grid, one connection to the bottom grid down there with the middle boy. Where's Wally? Where's the middle wire? You know to track it down.

Whoa. There's our. There's the other end of our connection, right? There's a third. There's a third wire.

It just goes to there. It doesn't go to the inner diaphragm. It's not your traditional let your static speaker what it's going off to here, the heck's going on. All it does is connect to this metal plate here.

Which, that's it that sits on the back of the rear look. Well, let's call this the rear grid here. and that's it. That's all it connects into.

the heck's going on. How does that work? And sure enough, you know you measure it again. There's actually no electrical connection between the top and bottom grid. They're there.

They're open, as you'd expect. They're just two grits, a physical metal grid mesh thing separated by some sort of dielectric that's not connected to anything as far as I can see. Well, that certainly explains why this thing was fully operational when I disconnected the case and disconnected this, which was supposed to be your traditional diaphragm in the middle. So there is no diaphragm in the middle.

It's simply a top and bottom grid separated by some sort of dial. A tricky thing. and they drive that that you know, the thousand volts or two differential and it acts as a as an electrostatic speaker. So okay, that's how they want to play it there.

It's You know. it obviously does the business because it sounds okay and this metal plate at the back is just for you. No grounding purposes. really.

it just connects to the shezzy ground and that's it. So it's just purely a differential drive. a grid plate system. II thingamabob as well.

What's happening with the physical construction there? It's just taped together. You can see that there's that you know like this. like a like a almost like a tape and adhesive tape. Holding that off that cross pattern is actually something that's stuck on to that.

it's like a separator. I'd say it's like just that they're just using that as a physical sort of a separator. and then as this is fabric kind of stuff in there. what sort of actual material that is? I'm not not entirely sure, but you can see that's very much like a like a fabric, very thin fabric.

Wow Fascinating. And it's exactly the same on the other side. So there you go. higher voltage across those grids, a little sort of separator, some sort of fabric, and Bob's your uncle.

You've got yourself a fairly effective electrostatic speaker. Hmm. so I'm putting this back together. and I mentioned before that I was impressed by the physical design and construction of this thing.

and yeah, I can see all the method to how they're doing this. When you actually assemble it from that, you know from the scratch position. I didn't entirely take the whole thing apart like hinges and and stuff like that I took a part of the top thing off and the front cover and all that, but at all really goes together very nicely. This is where systems Engineering systems design.

can you know really make or break your product cuz to make it this small and compact and get the performance out of this thing and yet have it. You know, low-cost manufacturable, and and all that sort of jazz, then you know it's a big part of product design. Okay, so I got some weird L happening here. I've got my high voltage our pro connected across one of the the output of one of the electrostatic speakers there.

I'm only on ten to one and where it's a twenty volts per division so we can see like forty volts there. You know, peaking it may be sixty something like that. but I am NOT going huge volume at the moment. So yeah, it's like it's not a thousand volts.

But the problem here is that I don't know how much the probes actually loading it down. So and I've ever really turn it up here. We go there, we go. that's twenty volts per division.

So yeah, well, over a hundred volt Peaks there. and if I actually go between the center tap there and one side of that, you can see that we're much lower in aperture, but down to ten volts per division now. So it's a differential. that's that's doing all the damage there.

So there you have it. that's the you who Trevor low s It's been around. Well I'm not sure how long this new models been around, but the original model. This is like a second generation one I believe.

So yeah, they've made some improvements and they claim all sorts of you know you read the brochure and it's wink wink wink wink. but it actually seems to do the business as far as like it's it's fit for purpose is fantastic. So if you're after a Bluetooth speaker that does the business um, this one seems pretty good. So I'll leave a link down below.

Thank you for being Q for sending that in. Wasn't as fascinating as I was hoping it would be in terms of the electrostatics, but they are incredibly simple. They are essentially that, except it doesn't have your traditional diaphragm in the sandwiched in the middle of it. It's just using basically two metal meshes separated by some sort of faux green fabric II like material if you've got any details on what that might be or they don't seem to have a a patent on this.

But if if I find one or you can point one out, let us know. But yeah, it's a there electrostatic speakers and the directionality of the speaker seems to be, you know, a much more forgiving than your more traditional you know monitors or hi-fi speakers. Well where it really matters, you know where you have the tweeters actually direction. you've got to have them pointed right at you.

This one's seems a lot more forgiving. So yeah it's actually it's quite impressive. And as I said, the engineering in this is very nice. But yeah, they've I don't know if this is some newfangled electrostatic thing or whether or not.

oh, your electrostatic fanboys, let us know this is the first time I've torn down electrostatic speaker at all. If you know of other ones or you've done one yourself, you've got photos. Please link it in and discuss it down below. So anyway, I hope you found that interesting.

It did. Give it a big thumbs up and as always you can comment on the EEV blog forum and down below. And yes I still have some of these I'm clearing them out. Eevblog High Voltage Pros: Really Schmick High Voltage probes over on my store currently discounted.

Hurry up quick! And yes, One Twenty Ones GW is a back in stock and yes I accept crypto as well all forms of cryptocurrency on my store beauty. So if you want to dump some crypto and get some swag, go for it. I've got a shell something to stay in business. Catch you next time.