spritzer

This bias supply will blow up your headphones very quickly so don't use it. Everything is wrong with it so I'd completely scrap it

You think those are output protection resistors... on half of the signal? Yup, makes sense. Notice the cap there, with the resistor? Might that be a fucking RC network?

You said they would serve no purpose, that is clearly wrong. Stax never put any protection resistors in any SRD unit (or anything else for that matter) as they weren't introduced until 1994 with the T2. I don't need to enlighten you about shit but I will call out stupidity when I see it.

The 5k1 output resistors are very much necessary, you clearly have no idea why they are there.

What are the offset voltages? That's when you measure between each of the 4 outputs and ground. In theory you can have the balance at 0VDC but one output is stuck at HV+ or HV- It is also a good idea to measure the rail voltages as the resistors in the power supplies in these love to fail. Also... is the last cap of the main reservoir caps, closest to the tubes bulging a bit? Might just be the reflection.

I would always recommend swapping out the card slots on these as they all fall apart. Also, watch out for the transformers leaking... I found that out the hard way as they aren't grounded. Wasn't there just one pot per channel on these? Should be the balance so go to each tube anode and adjust for 0VDC.

I would just leave them in if they work fine

Yeah and it is 2SA... that is always a PNP.

It's an NPN so no... not a replacement. There are no PNP parts that are past 600V these days.

The voltage limitation of the tubes is an issue but the CCS does wonders to the amp.

That's pretty much how the Stax tube amps sound in stock form... not a whole lot of dynamics on tap there with those tubes and resistors as a plate load

I'm not sure if they have been posted out in the public yet but should be soon.

There is the EX-1a too: https://www.eslabhk.com/ex1a The prices are also very fair and I will be buying both.

I can't wait to try them.

Plus it has Apex chips in general so it is awful.

Gotta love Edifer making worse parts at three times what they used to cost. Still that price in Italy is just a ripoff, the arc from Stax directly in Japan is 6600Yen which is about 50$.

Yup, transformer in each cut and weight is close to 1kg. I rebuilt one 15 years ago and recently got the urge to mass with one again. 700V bias (well cut off so probably lower in practice) and I'm going to put new earpads and a headband on them.

That's what I was thinking, the margins must be insane on these as its a store not really known for any good deals. Now I'm thinking if I did a deep dive on this earlier in the year when I got a set dirt cheap... or I just sent all of that to Kevin? Well first off input, bunch of parts here USB xmos, A/D etc: All of this leads to a pair of ESS 9028 dacs: Not the best picture but that looks a lot like filtering to try and make up for the utterly retarded driver design: Finally output stage... yeah this is pretty dire. Remember this thing is 4k$... Now how does this thing actually work? The clue is those two gray caps and the wires going to the headphone plug. 450V B+ on a single rail so shall we say a maximum voltage swing of ~840Vppss and the bias is clearly 2000V. The bias is superimposed on the audio signal after the output caps and then we have the grounded shield, that's it. These are even simpler than what Koss were doing in the 60's where the back stator on the ESP6 (and 7, 8 and 9) are grounded but otherwise normal electrostatics.

I don't think Warwick are doing so hot these days... I snapped this in Selfridges on Oxfordstreet yesterday and I might have been tempted as an insane collector if I didn't already own one of those piece of shit amps. Well that and it sounds like shit... there is that issue too.

Unless it is a set with the handmade markings and the slightly smaller housing, they are all 200V bias so any normal bias would work just fine. I'd remove the cap after the ballast resistor just to be sure but that's about it.

Yeah, that is quite sad. We bought a season ticket the winter of 2222/23 so we went there a few times a week. The gap they are filling up in the second picture is indeed the walkway to the lagoon... and those guys are utterly nuts for working so close to the lava

This is a small one but already causing plenty of damage. This did crack me up from last night: All in Icelandic but on the bottom "It is unlikely that there will be an eruption in November"... from the day before. Then the next piece of news is "eruption started next to Stóra-Skógfell". Here is a view from 9am this morning from the small town I grew up in at the west edge of Reykjavik

Could be an ESP-7 too as they used the same shells/headband but I'm not sure if the cable on those was ever coiled.

Same really, the swing back and forth from working and then the channel imbalance sets in again. I bought another set that I've been using so I'll likely scrap this for parts.

I won't be getting a pair try out but I might send one of the originals in for an upgrade. I have an original set sitting with Kevin in the US so that's an option. The price is silly though... they were already pretty expensive to begin with.