spritzer

Thanks to the wonder of modern PCB manufacturing, this showed up yesterday: I bought the boards fully assembled as I'm lazy and I hate SMD soldering so I just had to add the connectors. To make it a single sided load (so the assembly would be much cheaper) the board had to be a bit wider than the stock board so one of the transformers had to be moved around 10mm. Just remove one screw and slide it to one side. Drill a new hole and it is done. Now the EHA-5 still sounds like shit but it is at least safe for the end user.

No, there is no transformer on the output

Those two parts in the middle are just the copper standoffs and the other look like connectors to something below the board. I'm not sure about that amp though, just look at those output inductors trying to stabilize the circuit and are those modules similar to the ones used in the Gainclone? Not very discrete then...

Hehe, maybe they can market it like that?

Throw it out and start again? I mean this truly terrible stuff but I stripped it down yesterday and yeah... I can see why Topping has a reputation for failing a lot as this was probably soldered by people not being paid a whole lot. Some joints have barely any solder on them and there is flux everywhere. The transformers are clearly styled after the Stax SRD-7 units (down to the color of the wires) but who knows how they are actually wound. It is quite tricky and expensive to wind a really low capacitance transformer. The back of the Stax socket board and yup, straight links to the socket from the bias and the transformers. Look how dirty this thing is, it is covered in muck. Sorry for the shit pictures, I didn't want to drag out a better camera for this. This is not good... Here is what I'm doing to my own unit as I ripped off the Stax connector PCB: This simple board just adds some high voltage resistors to the bias line, adds output protection resistors (also HV units) and zeners to clamp the output so it can never go over 1150Vppss. The board is designed to go on the smaller pins of the socket so this could be fitted to the amp with the original board in place if the connectors are just cut off.

Jest before I stopped playing with it last night I took some measurements, I fed it a 10kHz squarewave, 1Vpp from a function gen and while it was a pain to get a good ground in there, we are not dealing with high speed signals either. Here is the input to the amp: Nice enough squarewave but here is the output of the amp, set to my usual listening level: This was one leg of the output of the transformer, here is the other: Yeah.... this isn't great, is it? Might be the worst I've ever seen but I naturally forgot to measure the primary of the transformers and I've already started to rip the unit apart. I may do that later.

So, I listened to it (as next step it to fully rip it apart) and in my regular test rig which is a Teac UD-503 dac driven over USB. Output set to 0dB on the DAC (no attenuation and no gain either), balanced inputs and I had to use the high gain function and volume control at 2-3pm on the dial. I could listen at full volume level, not something I'd recommend but yeah, this thing is just fucked. This is with SR-207's (my go to test headphones) so anything more power hungry will suffer even more. Now how does this sound... well mushy and very peaky. The midrange has this haze to it and the treble is very... alive. Bass is exaggerated but not always so, it kinda comes and goes as this thing struggles to get any output. Sound-staging is also pretty terrible so I find it hard to recommend this over the Stax SRM-252S. I also put it on a Kill-a-watt and at full output it draws 7.5W from the wall. That's not a whole lot of power there...

Well this just arrived and as is our fashion, it has not been plugged in at all before I rip it apart. I'm having some camera issues (bloody Lightroom) so not as many as I'd like. Now first off why this belongs on a trashpile... here is the output: It's a pain to get a camera to focus between the transformers so I ended up grabbing the phone. Those are the ballast resistors, two 1M units in series and one 3M3 unit, all in 1206 package so likely 150V rated. Yeah no... just no, this is not good enough!! It gets worse though... It's a shit angle but here is how the transformers connect to the output socket: Now do you notice any parts on this PCB except connectors? Nope, neither do I... there is no protection on the output at all. No 5K1 output resistors nor the clamp circuit found on all later Stax adapter boxes. This thing will kill your headphones when pushed hard enough and there is nothing to protect the user if something goes wrong. Yup, pure class here... zero fucks given. Some other random pics, main amp runs off a +/-15V supply and the PSU brick is 15V/2A. Preamp presumably and the whole thing looks to be AC coupled through those electrolytic caps so that will not sound good at all. I see no other reason for those caps to be there so yeah, who does something like this. At least the volume pot is 4 gangs so the thing is fully balanced. Conclusion, without even plugging it in, this is a pile of crap and should not be used by anybody. The small changes to make this secure and sound good cost next to nothing but nobody cares. Best avoided unless you want to have a special talk to the manufacturer of your headphones as to why there are holes in the diaphragms... Now if I have time, I'm going to fully strip this thing down and design a PCB for the Stax socket which adds full protection and a clamp circuit. Fix the input caps and other issues that I find and this might a semi good 400$ amp. Personally I'd take a Stax SRM-313 over this pile of crap.

Hehe 10K$ for this thing... well I'm sure the owners of the 3ES are looking for an upgrade. Given that no Woo amps or adapters I've ever seen have the proper safety features... I very much doubt Ray will use them either.

So I've been thinking about this... and I've seen those numbers before, 1800Vpp and 200mA. Took me a while to figure out where but yeah... it's our good friends Apex. See the list here: https://www.apexanalog.com/products/linear_selector.html Go under high voltage and see the PA194, PA95 and PA94. All of them are rated at 900V (+/-450V so 1800Vpp if you live in magical fairy land with no losses) and 0.2A or 200mA. Now these are absolute design limits, nominal current is 100mA and given the power limitations of each package (30W or so) there is no way you can reach them simultaneously. This is better than the absolute trashfire of the PA97 Woo are using in the 3ES but not by much. Now if this is what Ray's using then the PA94 and PA95 are roughly 150$ each so a 600$ amp. This plus a PSU and something to drive this and yeah, no way he can charge more than 4k$ for this or people will just laugh at him. This will not stand up to a Stax 727 (unmodified even) so what's the fucking point.

It's for the "tube effect", there is one on either side of the amp.

Holy fuck that thing is ugly and yeah... color me skeptical of those numbers. 1800Vpp would point to either +/-450V or +/-500V rails (given the regular losses) so either 900V or 1000V at 200mA. That's 180-200W, per channel and those heatsinks are not big enough for even a tenth of that. I also love that Ray dug out a 20 year old CD player (which I'm shocked still works as I had one of those)...

Indeed but I hope the power amp has moved on a bit from the early 80's... It's mediocre crap from China, I don't see how that would be the case. It's one of a host of similar products that don't stand out at all.

Yup that's the M03... it's not good and there are some others on the Chinese market.

King of the trash maybe, not much more. Assuming that it is well made (a big ask for Topping), it made to spec (also something I really doubt) and will not burn up headphones... This will be on par with the Stax SRM-1Mk2/3/313/323 amps in terms of performance. Might be ahead of the 353 or D50 as they are both trash. Indeed and also a small issue with the 2000Vppss voltage swing, if you go much above 1200Vppss... there is a major risk of burning up the headphones. Completely useless stats.

So it is basically what Quad was doing 50 years ago? 😉 Now given it is a step up transformer solution, the light weight of it does worry me as good quality iron has to have a certain weight to it.

The Topping EHA-5 was released today and I've naturally bought one. I don't have high hopes for this though as of yet, no good electrostatic amp has come out of China - just different shades mediocrity. We are currently taking bets as to what's inside, I think it is either a Koss clone or a speaker amp driving a pair of transformers. That or the SRM-001 circuit (yeah the portable one) is about as it good as it gets from China. Speaking of China fucking things up, I've been trying to source some Stax parts recently and everybody has the same story, Edifer has fully taken over Stax and fucked it into the dirt. Maybe they are just trying to get rid of the old distributors to do it themselves but yeah, nobody is happy with the way Stax is run now. I fear we may be heading into a very dark time indeed, similar to what happened to Quad back in the day.

If these were new tubes, then that can happen.

I agree, I don't see anything terrible here nor anything great for the matter. I don't see why they are using 5% resistors in this day and age but nothing else really stands out. Well only that they really like their flag connectors...

We did release the full schematics so yeah... it might be a clone. A clone of a terrible amplifier...

Yup, they are very hungry tubes. Given what these are designed for, tube life should be just fine if not run on the extreme edge.

Good point, can any of the mods copy it over?

This thing is 12k$ so with a total of 500$ in parts... how much is the paint job and how glorious is the very high distortion at the output.

I only see two wires coming into those C-core lumps, red going to a bunch of resistors on each channel and the green going to the 300B's. Could be outputs on the other side but how else are they making a balanced output signal. Schematic points to the - output just being grounded but that can't be right.

This is very sad and a lot of Single Power influence here, cheaper parts used in series and parallel. I see the A, B and C markings so is there a PSU schematic as well? Edit: Never mind, I found the thread and wow... google translate may not be doing some of those people any favors but there was some class A stupidity going on. Point to point always sounds better than PCB's!!! The Viva may be crap but it sounds so good with the X9000!! Yeah... might be because the X9000 is also crap? Just an idea... Anyway some more pics from that thread: Just look at this mess, hot glue everywhere (where they should have used lacquer paint) and cheap parts everywhere. Not sure why that woolen stuff and zip tie is on the selector switch but that is the ultra cheap switches I can buy at the local store for 2$. Then we have this gem... why is a part of the shrink wrap on the cap missing and just what on earth is that supposed to be? A bridge rectifier? This might actually worse than Single Power but remember kids, a nice PCB with length matched traces sounds far worse than this!! Now look at this picture of loveliness, a Rifa X2 (as in power supply suppression cap) ,known all over the world for their tendency to fail short (look up Rifa madness) being used in a "high end" amp. Not even Single Power stooped this low, he might have "tuned" the circuit by placing an Audio Note silver cap in series with an Orange Drop but they are at least good caps. This is just pure and utter garbage. I just love this picture, look at that mess of wires into a bundle of solder. Extra price for the burn marks on the cap as zero fucks are given here. They should seriously have this as a promo picture. Last picture and would you look at those XLR inputs... yeah that's one way of dealing with a XLR to RCA conversion... just not hook anything up to pin 3 of the XLR sockets. I'm sure there is some owner of this piece of trash that claims massive improvements when it is run balanced... Also, look at the soldering on that, I'm sure those RCA's came with nice ground tabs but nope, fuck it, let's just solder directly to the thread and have it leaking down and almost touching the center pin. Lastly, I just love we are getting this from my good friend at JR Audio, one of the few builders of electrostatic equipment who is actually worse than this. I wonder if he's looking for pointers to becoming even worse?