SO ebay is completely off the rails on all things stax.

I see what looked to be a standard bias SRD-7 for $259. Seller claimed

it supported pro bias cans. I messaged him to see if it was modified.

Answer:no. So another BS claim by a seller. You can plug it in and use it,

but it certainly isn't pro bias. It will sit on the bay for the next month like

hundreds of other overpriced stax crap, most of it "untested".

No wonder multiple miracle stax energizers are popping up from 

shady start up companies.

 

Yeah, the used prices are pretty nuts. 

Much of the Stax gear sold on eBay comes from estate sales bought by people who don’t know what they have. I was lucky when I bought a 207 pair & a pair of Lowther drivers from an audiophile who resells what he finds at those sales. The prices were good & everything was as represented. The obvious difference was that he knew what he had & priced accordingly.

Want to share some measurements of a few Stax. These were measured by oratory1990 on an industry-standard GRAS 43AG rig. All but the 009S were my personal units.

SR-007 MK1

SR-007A (2018 aka MK2.9 version) - with blue-tack mod

SR-009

SR-009S

My personal favorite without EQ was the 007 MK1, but the 009 with EQ is my favorite overall. They all become more similar than different with EQ, of course. Plus the 009 ergonomics agree more with my head

More here: https://www.reddit.com/r/oratory1990/wiki/index/list_of_presets

Same as above, but in picture format:

SR-007 Mk1

SR-007 Mk2.9 Blu tack

SR-009

SR-009S

 

Here is how the SR-009 reacts to having a bad seal on the sides of your head (and thus 009S as well). Again, thanks to oratory1990 for his detailed testing.

 

Would wearing spectacles be classed as having a bad seal?

Depends on the thickness of the frame, I guess. It won't make for a perfect seal, but it also won't get you to the worst-case scenario (red line on the graph)

A pair of mint SR-007 Mk 1's arrived yesterday, so my KGST should be happier now! Bit of a step up from the SR-313's I've been using.

Beautiful man 007! 

L700 MK2 has arrived, pleasant sound so far tho I have to take my glasses off otherwise I get un-even bass :/

 

L700 Mk2 impressions based on less than an hour of ownership:

First of all, the fit is very much improved. The Mk1 had an idiotic design where the top of the earcup couldn't swivel outwards far enough, and it ended up putting too much pressure on the top of the earpad while the bottom wouldn't even seal properly on some people. The Mk2 has a different y-fork, yoke, whatever you want to call it, which is bent inwards and lets the earcups swivel more, and as suspected it creates a better fit. There's still  a bit too much pressure on the temples but it's tolerable and at least it seals. And hopefully we'll have no more flimsy plastic pieces breaking. So, it's a step in the right direction.

Those same words can apply to the sound too. The overall tuning seems warmer, tighter, and more focused. I had to EQ the treble down on the Mk1 to make it tolerable, but the Mk2 so far doesn't need it. It's also less diffuse and overly ethereal, more focused and defined, and the bass doesn't have the big midbass bump anymore and is tighter. About the only complaint I have is that the midrange weirdness from the old version is still there, and vocal tonality just sounds off. But a small dip in the EQ around 1.2khz seems to reduce this, so whatever problem is going on seems to be somewhere around 1-1.5khz. The presence region also sounds a bit recessed, kinda like the SR-007 but not to the same extent.

Overall, it's definitely better. Sounds a bit more normal, more like vintage Stax and less like bright, alien modern day Stax - but not totally fixed yet.

On 10/8/2020 at 4:30 PM, catscratch said:

The Mk1 had an idiotic design where the top of the earcup couldn't swivel outwards far enough, and it ended up putting too much pressure on the top of the earpad while the bottom wouldn't even seal properly on some people. The Mk2 has a different y-fork, yoke, whatever you want to call it, which is bent inwards and lets the earcups swivel more, and as suspected it creates a better fit.

Thanks for mentioning this catscratch. For the MK2, is it still the case that the top of the earcup can't rotate fully past the yoke because of the little tab up there and the flared rear edge? I had a L300 years ago I got rid of right away because of those exact fit/seal issues and was hoping Stax would address it with a revision.

Yes, that is still the case. In fact, it's worse in a way, because in the old model the y-forks were made of plastic and you could muscle the earcup past them (though they had a tendency to snap if you did), but becase this one is metal, you can't. However the new design allows for a wider range of motion, and the fit is definitely better than in the old one.

I'm guessing someone with a 3d printer can probably make a y-fork that bypasses the tab and allows for full outward articulation. I know SoCas makes Stax mods, maybe they can do it, but I haven't contacted them about it. It'll have to be both taller and wider, since the earcup itself is wider at the inner side than the fork.

Edit: Look like they already make something similar. No comments on style...

Edited October 20, 20205 yr by catscratch

Well dang, that probably means I'll be sitting out this iteration myself. The printed solution looks interesting, then again I feel like Stax should be nailing this aspect so the wideheads don't potentially need to resort to DIY fixes.

Appreciate the followup, guess I was confusing talking about flared rear edges when I could've simply referred to the wider side of the earcup as you were saying. I think I remember taking out the L300 cups and trying to reseat them so the tabs were on the outer side of the yokes and IIRC that didn't work at all. Too far rotated and the cups didn't go back in properly with that wider side grinding on the yokes 🤦‍♂️

Can anyone enlighten me on the visual difference between the SRE-750 and SRE-950S extension cables? I'm struggling to find anything other than stock photos, which aren't helping. I'm guessing the ones I've acquired are 750's. Thanks.

The SRE-950S has yellow markings.

Nice one. Thanks for that. 👍

Seems a bit arse about face. Yellow for silver and white for copper??? Maybe I'm too logical.

Hi,
i'm owner of L700 mk2 + Stax D50 amp.
And I love this combo.

I plan to buy more Stax earphones soon 
I'm looking for informations about amps, and I saw this amp LTA Z10e.
Anyone try it ?
How it sound compared to BHSE or KGSS amp ?

21 hours ago, Isseki said:

 

That's a lot of money for a unit without much of a track record.

It's a reworked integrated tube amp. 

until someone trustworthy checks them out, it's just another FOTM.

And yes, even stereophile is a bit suspect any more. What do they know about

headphones, and stax.

Edited October 26, 20205 yr by ktm

31 minutes ago, ktm said:

That's a lot of money for a unit without much of a track record.

It's a reworked integrated tube amp. 

until someone trustworthy checks them out, it's just another FOTM.

And yes, even stereophile is a bit suspect any more. What do they know about

headphones, and stax.

Yes, i found just one or two reviews, it's not enough to know how it sound, and it's a bit suspect.

6 hours ago, Isseki said:

Yes, i found just one or two reviews, it's not enough to know how it sound, and it's a bit suspect.

7K and its BASED on an amplifier that is class AB and has a cheap alps low end pot not even a TKD....

no details of the topology...

no photos of the inside....

no details of the voltage swing for the stax... just the bias voltage

0.5% distortion into speakers, ok you might not be able to extrapolate from speakers to stax but... the T2 is much better than an order of magnitude better than that at (0.02% THD) at 575Vrms output. At 600V rms the T2 is starting to clip and even then the THD is still an order of magnitude lower at 0.05% THD and thats over a wide bandwidth of 20 to 50khz...

I bet the case is not big enough to fit just the power supply of a full T2 into it....

here is the inside of the amp its based upon

https://www.lineartubeaudio.com/products/zotl10-mkii

erm where's the power supply transformer?... it has a seperate power supply no details and no photos.

"100V / 120V / 240V operation: Auto-switching" ... sounds like a switch mode power supply????

nichicon 85C cap right next to a bunch of valves....

looks legit to me...

Wait its a ZOTL design and has no output transformer.... just like the blue hawaii, mini t2, full T2, alpha centauri.... erm just like almost every stax headphone amp... (yes im ignoring the fact its output transformerless into speakers but this is the STAX forum...)

 

 

 

 

Edited October 26, 20205 yr by jamesmking

52 minutes ago, jamesmking said:

no photos of the inside....

I found this photo but i'm not sure it's the Z10e
edit : it's the Z10

 

7 minutes ago, Isseki said:

I found this photo but i'm not sure it's the Z10e

 

that's the integrated amp only 4K 

Edited October 26, 20205 yr by jamesmking

FWIW, I like some of the LTA gear, used to own the Micro-ZOTL 2 (the first non-Berning incarnation).  Was a great little amp for not big $, and combined with my Exogal Comet DAC had some folks at a NH show saying it was the best they'd heard from the Senn 800.  I also met a couple of the LTA guys at a NY show, pretty nice/cool, with good music taste for the demos.

The circuit is licensed from Berning so it has some standard there.  TBD on parts used etc.  But what I had was a pretty solid amp with very good sound.

Now, that said....the prices have shot up WAY too much for my liking.  And yes, having never worked with stats, there's reservations that are perfectly valid.  At a  lower price point, I think they'd be worth a listen.  But not upwards of $7k.....

6 hours ago, jamesmking said:

no details of the voltage swing for the stax... just the bias voltage

At the other side, LTA rep posted this info:

"Frequency response (8-ohm load): 6Hz to 60kHz, +0, -.5dB
Input impedance: 47k
Electrostatic Headphone Output: 5 pin Stax interface, 580V bias

One additional bit of info that's not on the page is the output voltage, which is limited to 410Vrms on the Z10e. STAX themselves recommends that "maximum output with 470 Vr.m.s. or below for any amplifier driving STAX headphone in order to avoid damages to sound elements."

"there are no transformers. The electrostatic signal comes straight off the tube, and due to ZOTL's unique topology, the tubes run natively at 750V, for a 1500V peak to peak (each channel has two tubes, one is for the bottom half of the signal and one for the top half, so the full voltage swing is both added together). The ectrostatic headphone output is live all the time, because we didn't want to degrade the audio signal with a switch."

6 hours ago, Jon L said:

At the other side, LTA rep posted this info:

"Frequency response (8-ohm load): 6Hz to 60kHz, +0, -.5dB
Input impedance: 47k
Electrostatic Headphone Output: 5 pin Stax interface, 580V bias

One additional bit of info that's not on the page is the output voltage, which is limited to 410Vrms on the Z10e. STAX themselves recommends that "maximum output with 470 Vr.m.s. or below for any amplifier driving STAX headphone in order to avoid damages to sound elements."

"there are no transformers. The electrostatic signal comes straight off the tube, and due to ZOTL's unique topology, the tubes run natively at 750V, for a 1500V peak to peak (each channel has two tubes, one is for the bottom half of the signal and one for the top half, so the full voltage swing is both added together). The ectrostatic headphone output is live all the time, because we didn't want to degrade the audio signal with a switch."

T2 frequency response is at least that good

so it's confirmed to be running class AB....

7K is an awful lot of money that's shop built blue hawaii se with a really nice potentiometer and 0.1% 15ppm resistors. Or two modern full T2s if you go DIY... so its up against the best of the best.

1. does it have interstage coupling caps (bad for sound)?

2. is the signal path cap free?

3. is it using constant current sources? if so where?

4. does it have a 5M ohm resistor on the bias to protect the headphones.

5. does it have 5.1K resistors on the outputs to protect the stax headphones?

6. how quiet are the power supplies?

7. is the B+ delayed on startup?

As a speaker amplifier it's interesting, as a stax amp I am not convinced.

Edited October 27, 20205 yr by jamesmking