spritzer

That was brilliant Milos. I think part of the problem was the general suck of the group. We should have sent you a KGSS as a baseline.

I did just check some of my 6S4A's and none have a connection at pin one. Still some versions might use that so better safe than sorry. If the wrong part of the tube is connected there then the amp might go boom... That resistors is so small in value but since I will be removing the plate resistors in this one it was a good idea to do a direct connection.

There are at least three of these already built...

The 5K resistor has no penalty or drawback. Too fucking cool!!!

Tyll is most certainly not part of the hype train. Electrostatics are not his usual thing though so that might be a factor.

The thing about the bass is that it's at the same time way over the top and anemic. There is no sub bass at all and it has a huge peak higher up making it sound like a bloody dynamic. This slow, muddy, thundering bass that over powers everything. As coloration's often do they stand out more on some tracks than others. On some you have the bass drowning out everything and the coloration in the top end wanting to claw your ears out. It's that bad with flat headphones, I don't even want to think how bad the 009 is... Edit. I didn't want to work on the LL today so I instead swapped in a normal bias socket on the 007tA I have here. That means stripping the amp down so it's fun to compare to something like the LL. Stax have thought this through so the sockets are mounted on a special plate so it is easy to get to them. Socket on the back that connects both of them that makes wiring neater and now all the switching stuff for the inputs is hidden behind the front panel. There is so much labor that goes into making these that it isn't even funny

I'm way too lazy to do another DIY chassis at this point but I think some DHT action is in my future. I'll at least order up the remaining parts for this 300B amp. Good to use some of these filmcaps too...

The CE tests is a basic test of electric compliance,hence the name, this is not some gold standard. It's the basic "will not catch fire on the spot" test and often called China Electric as makers of cheap crap flaunt it to make their products appear good As it stands the earthing on this LL does not meet the European safety standard as the earth can become loose so how is this the end of the matter? Also please show me the part of CE testing that extends to the units intended function and how peripherals connected to it are protected? The Stax amps are all CE and PSE marked and yet the headphones and the user are protected when using them. We need to make ECP make a Stax amp for us. Unknown tubes and transformers... when can I order one Doug?

But here is the thing, that wasn't a serious reply. It was just BS leveled on top of more BS. At the end of the day this is a 5000$ amplifier that is supposed to compete with the stuff Stax made and it quite frankly doesn't. I'm leaving the BHSE out of this as we all know it doesn't belong in any 5K$ amp comparison regardless of the retail price, it's simply too cheap for what you get. With the Stax amps you have dealer and distributor networks to think about and building an esoteric product to a price. They are also stuck in their ways so there are comparisons to be made. The parts quality in the Stax amps is superior to almost anything found in the LL except maybe those bloody carbon pots they insist on using. Been using the same stuff from the 70's so, stuck in their ways. Stax do skimp on PSU design, always have done but then the circuits don't need an overkill PSU to work and work well. The amps are bulletproof though and will last for decades and decades, even the truly abused ones just need a bit of spit and polish to spring back to life. They also measure excellently and are easy to service. Well not the SRA-14S as it is built in the same way as the LL. Wires everywhere and not a terminal block in sight. The LL on the other hand has a pretty chassis but at double the cost of the 727 offers no benefits. It's more powerful but the sound is even worse, fat, bloated and thick. Then we have the safety issues, no output resistors, ballast resistors on the bias supply that will not work at the 600V they have to hold off in case of short and an earth contact that isn't legal anywhere. Seriously, who doesn't put a locking washer on the nut? This is basic safety stuff... Measurements posted aren't real, not even close and the build quality is appalling. Pictures don't do it justice, it's just the sheer lack of any common sense that gets to you. Stuff like the switch circuitry has a ground plane but why on earth doesn't the rest of the amp use it? Long ground traces, especially on the amp pcb aren't good engineering, especially on the cheapest PCB's money can buy. Just to be clear, I was agreeing with Jacob that the large majority of the audio market is just snakeoil and BS. Should have stated that...

Yeah, I agree with Jacob 100% and that post is just full of BS and lies. Not that I expected anything different... Now back to fixing this pile of fail. I'll get some J74's so I don't need to dip into my stash of J109's and I'll order the parts to fix the PSU too. Having no capacitance to speak of after the regulator makes no sense to me. Either it is due to the designer being an epic cheap scate or because it likes to blow up with too much capacitance. Some film caps should be ok though.

6c33 is also very fuzzy about pretty much everything. The 6P21S could work as an output tube at just 600V. Not a whole lot of data on them but it would be doable and quite cheap. I'd personally go for some nice IDHT on the front end as it's easier to power and the DHT's really need the high frequency filament supplies to behave so they add up quickly. The 300B is overrated for pretty much everything but I like the challenge of trying to make something of them. I also have them and pretty much all the parts needed for something like that. PSU will be a CLCLCRC or something like that with a tube rectifier and all film caps. The EML's are a bit nuts but also truly great tubes. Kevin has designed a 12 tube DHT amp which used a quad of 20B's just to drive the output 845's. Never asked for the schematic of that one as I don't want to see it. Then I might actually build it...

Yes, now it just acts as 006t. TVR3 and TVR4 could just be removed. In fact you should connect to the other side of them. Do not connect anything to pin 1 on the tubes as that will cause problems. It's used inside the tube... Here is the last one I did showing the removed TVR3 and 4:

I will do something similar for electrostatics but no way in hell that is better than having a good driver stage. So for a full DHT amp you'd need some driver, I'd use a IDHT here as there are less issues. An amp like this would get very expensive... very quickly.

I like the idea of an "optional" phono stage that is on the main PCB. These people have never heard of plug in boards?

Sure, why not. I do think a version of the KGSSHV could be built and sold for about 1200$ even in small numbers and with our high standards. If I ever get to work off my project list then this is something I'd consider doing, at least the R&D side of things.

Transformer after another transformer is fine if the first one sees the correct load. Run them unloaded and you get into trouble real quick. Got any tubes in mind for that? I've been down this road and I always come to the EML 20B for output duty. It's the right mix of voltage handling and ease of drive compared to something like the 211/845. There is a 300B amp in the works too but it is transformer coupled, similar to the Ciuffoli stuff but with a better PSU.

In the ES-1 and ES-2 the transformers were actually way over spec, it's just the rest that was utterly fucked. The worst were the bias supplies, filament supply, caps run way over the rated voltage and the minor detail of the -110V offset always present. In this LLmk1 the parts quality isn't great and just enough to do the job is the mantra. Why use the CMF55 resistors when the CMF60 units are not that more costly and will result in less noise. Ditto for the higher wattage resistors, using larger ones can only be better. Same for the input fets, those aren't good parts and J74's can still be sourced. The output devices make no sense to anybody and Fairchild does make excellent 800V BJT's which are a perfect fit. Isolated too so that makes mounting easier. One other point that needs to be dealt with, how does this amp stack up against the other amps out there. The only comparison review was done by Tyll and lets face it, all the other amps except the BHSE are fucked in one way or another. 727 is far from linear stock, the SRM-007tII/A is very dull, the WES is a quad of single ended amps with a choke on the output trying to push the EL34 at 600V and the A-10 just needs to be experienced to know how lots of distortion sounds. The rest of the impressions are by the regular army of shills or people with very little exposure to the high end electrostatics. You may take my impressions anyway you like but the fact that one of these amps is approaching 10 owners now in the span of a few months says something about the sound quality. I would welcome somebody like Schit into the market. We have been taking to a number of Chinese manufacturers and there is interest but who knows what will come of it. Just this morning I got an offer to build for me anything I'd like. Not interested in that but it would certainly be possible to build a smaller version of the KGSSHV, fully SMD except the output devices. As for the amp, I've been busy with other projects but the pot in the bias supply is giving me problems. Bloody Vishay crap so I'll rewire it a bit and it will work just fine. After that it's time for the amp board, remove the diodes on the power input (those make no sense), I ordered some LSJ74's so if I get two matched pairs I'll use those or 2SJ109 to replace the Fairchild's and probably remove the transistor in the CCS and use a LED instead. Also some local capacitance on the board is a given. Where to put large filmcaps though...

Using the regulated output is a good idea and what I did in the Liquid Lightning. The zeners will just add noise though.

Let's just start off with one thing, nobody on HF that they value can read a schematic and make any meaningful judgements from that. There is a whole lot more to it than to just know what the symbol for a capacitor or a resistor is. Also assuming the lemming mentality that is the norm applies to the Stax mafia is just nonsense. We post the data for people to make up their own minds. That's the sole reason for this thread, educate people, and Alex is certainly amongst those as he clearly hasn't got the slightest clue what he's doing. Same reason why we did the Single Power stuff, the KingSound and why the EC Electra is next. People need to make informed decisions based on facts, not the shill drivel on HF or faked measurements. As Amos so routinely posts, most amps are based on the same designs (not true anybody who knows anything about electronics knows that) so why don't people post the designs? Why won't they post internal pictures? Because they have something to hide. If anybody doubts these images then I'll gladly supply the RAW's from Lightroom. As for the safety of the amp, of course it isn't safe. There are no output resistors and the ballast resistors will fail when asked to do their job. Think of it this way, you have a car with weak breaks which function ok under normal circumstances but what happens in an emergency? They won't do their job and it is the same case here. Under normal circumstances the amp works, sounds horrible but works but say somebody is using the headphones with wet hair. Not recommended but a drop of moisture gets into cable entry and shorts one of the conductors to the housing. The user then grabs the metal as something sounds off and boom, instant conductor to ground with nothing to limit the voltage/current. That is not a good feeling... What has been the standout of all of this for me is the constant cry from the shills and other people of ill refute about the wast difference between the LL1 and LL2 yet nobody has chimed in as to what said difference is. No internal pics naturally save for the one that shows the fucked DRV134/BUF634 phase splitter and the magical input wiring which is mostly just the same old cheap 1oz copper trace on the PCB. As for other makers entering the market, would anybody doubt the design and build quality of a Stax amp sold by Schiit or Pete Millet? The difference is that they know what they are doing, Cavalli has no clue.

Don't use those zeners on the bias. Just adds noise and it is already adjustable.

Fuck that... just wake up and drink some more!!!

It was just pointed out to me that I forgot to post this pic. The volume knob or rather the back of it: That's over spray from when it was painted. No primer or anything...

Here is an update on the next step of the mods. Now removing the PSU is an epic pain given all the wires soldered into it. Seriously, if people don't like terminal blocks then what about push on connectors? For fucks sake... All of the cleared bit is the bias supply. All those zeners add a huge quantity of noise and as a whole it's just unstable. Trying to fix some of this clusterfuck by adding connectors where I can. Here is the new bias supply. Kept things simple and used the same supply we've used on the KGSS for the last 15 years. It's an AC referenced voltage doubler but the input voltage is fed through a voltage divider. The input is taken directly off the V+ output so far lower noise than than the stock unit. I could have gone fully regulated but it would have been a lot more work so I just couldn't be bothered. I also found some 10uf/600V caps that fit at the output of the PSU which should help matters. If the protection circuit starts acting up then I'll just remove it as it is useless anyway.

Yup it was me and I'll post some pics. Speaking of which, this just arrived yesterday... This is a super rare, early SR-1. Housing material is completely different from all the later versions and models, it is smaller and the earpads are supposed to be made out of foam like you can see in the early Stax ads. Haven't tried them yet but I need to open them up first. All that rubber is perished as can be seen on this unique plug: Never seen one with screws and the full SATO Parts number on the front. Next to a SR-3 that I know was bought in 1971. Still looks like new though... Not the best picture but the SR-1 is a bit smaller, a whole lot lighter and the housing material flexes a bit. Good news is that the SR-1 housings are still sealed shut so they have never been tampered with. If I had to venture a guess I'd date them from 1960-1962. Condition is awesome for a 50 year old headphone... Also got one of these: The first full size Stax transformer box which debuted in 1965. Completely mint...

That's a lot of energy to burn off in the pass transistors so I wouldn't do it.