Stax SRM-T8000

[spritzer]

So my birthday present is finally here, the SRM-T8000.  I just quickly plucked it into my computer rig with the Denafrips Ares as a source:

Here I can compare directly against the Carbon CC and the as yet unrealesed new KGSSHV, budget edition.  Think of this one as the 727 if Stax had any sense.  Anyway, back to the T8000.  The packaging is classic Stax and no complaints there.  I do have some complaints about the casework though, the front panel looks awesome but who decided what to do with the rest of it?  Seriously that sparckly silver paint is just horrible.  Reminds me of some super cheap Chinese amps.  Yeah... not great. 

I had a quick peek inside to change the voltage to 240V and the procedure in the other thread is correct.  This is the same old Stax color setup with a small change (one connector is reversed) to try and trick people.  Some notes about the interior:

-The person who designed this needs to find something else to do as not a single fuck was given as to how this thing is put together.  Boards on top of boards with no reason to be there.  I love the volume control where you have three PCB's (one blank) sitting on top of the pot.  WHY!!!???  All of this could have been done on the back panel...  Also wires everywhere.  Bloody Stax living in the 70's... 

-The volume control (which they try to hide) is a plain old Alps RK27.  It's almost impossible to see but I moved the "shield" a bit and there was the classic Alps sticker.  For 6K$ I'd expect more...

-The PSU is certainly unregulated and the same as in the 727/007t.  Same 220uf/400V Elna caps. 

-Looks like the tubes are running at DC 6.3V.  4700uf/10V filter caps but I'll measure it later. 

-The amp is certainly just a 727 with the feedback in place and tube input stage.  Ohhh and for the tube rollers, not a chance to roll this amp so better just like the stock EH tubes.  Either that or somebody builds a special tester for this amp and sells tubes for it. 

Now for some impressions.  I'm a bit pressed for time now so I just grabbed the first headphones that I saw.  These are my own DIY units and I've been using them a lot lately as I've been tuning them.  The drivers are old SR-X Mk3 units so similar sound signature, the best highs you can find with glorious midrange and extended but super tight bass.  I'll go into the living room and grab some of the others over the weekend. 

Now what can I say about the amp...well I expected more.  The top end is the worst part, it's rather uneven and unrefined.  Grating even and slightly shouty in nature.  Seems to be the Stax house sound these days but it also makes me dread trying the amp with 009's and L700's.  I'm listening as I type this and I cringe from time to time, the upper midrange and treble is so bad.  The phones are sure as shit not to blame... 

Now the midrange is ok minus the glare but it also lacks the expansive nature that the really powerful amps give it.  It feels closed in... 

The bass...well it is nothing to write about really.  Nowhere near T2/Carbon levels of power but this really isn't the best set to try for bass performance.  I'll dig out the modded 007Mk2's to test that when I have time.  Here it is all a bit flat and lifeless. 

Conclusion time I guess, at least for now.  There are things I like about this amp, the front panel is pretty and it comes with properly wired XLR sockets but there is a lot I don't like.  I fucking hate the blue power led...Stax should be green or orange.  On top of everything above I also think this thing is horribly overpriced as it is just a fixed 727 which isn't a particularly great amp to begin with.  To charge 6k$ for this...is just not cool. 

More listening to come...

 

-

[Ali-Pacha]

First stage with t00bz, but after that, rather 717 (global feedback / resistor), as Kevin did say, or 727 (local feedbacks / CCS) ? 

Anyway, as a (very happy) BHSE owner, good to know. So he said

Ali

[Whitigir]

As I went through his post...I was like...Holy...Moly!

[kevin gilmore]

The VAS and output stage are from the 717. Resistor pullup on the vas stage.

The 727 had a current source that replaced the resistors and really was better once you fix the local feedback.

I'm sure that the stax mafia can make retrofit current source boards

birgir's thoughts on the sound are exactly the same as mine, the high end is rough and screechy

also all the extra connections on each of the plugin boards including the servo are going to get noisy over the years. very cheap connectors, not the augat that I use. also kind of wonder if they really are rated for voltage

 

 

Edited July 21, 2017 by kevin gilmore

[spritzer]

I grabbed the 007Mk2's from the "Stax shrine" in the living room (that's what my friends call the wall of Stax) and well...this is not good.  I've been throwing anything and everything at them and they... they sound quite frankly bad on this amp.  Everything from voices upwards sounds compressed and strident which is not normal.  Doesn't matter the type of music, recordings et al...they all sound bad. 

Now that I have the 007's I can test the bass and it is very much lacking.  Where the Carbon and T2 hit hard this one is just lackluster. 

Onward to some more listening... 

[mypasswordis]

But aren't the t00bs supposed to make the top end smooth and not digital sounding?? Time to tube roll Mikhail style!

[justin]

the square black connectors? looks like the .1" spacing ones i use on the Pico to connect the battery board to the amp

now i remember why i had to find a particular one. the connectors that use the same size pins as DIP sockets dont fit .025 square headers

Edited July 22, 2017 by justin

[wink]

[spritzer]

11 hours ago, justin said:

the square black connectors? looks like the .1" spacing ones i use on the Pico to connect the battery board to the amp

now i remember why i had to find a particular one. the connectors that use the same size pins as DIP sockets dont fit .025 square headers

Yup, they look like .1" to me and are used for everything in this amp.  Even HV stuff which is really doubt they should do... 

[justin]

they've used card sockets for years in the other amps, which seem high quality. never looked to see what the spacing is

[kevin gilmore]

the card edge sockets were .156 spacing on everything I have seen. The connector for the aux input slot is the same thing.

[mypasswordis]

The 727 pcb pin portion doesn't look high quality at all. Also .1 inch spacing is enough if done right, the amphenol header I'm using is rated for 1500V 3A

[spritzer]

The same sockets as on the 727 are on the expansion but Stax have been using these since the 60's.  SRA-3S used card edge stuff and the SRA-10S is filled with them. 

Now back to the T8000...and the sound continues to underwhelm.  It's just so damn strident...

[Ali-Pacha]

Even after modding it, I was never completely satisfied with my 727. Stock, it's just wrong, with bloated / murky bass, very metallic tone in the high mids, and you can't adjust volume correctly, because of compressed dynamic. Volume up to get some dynamic, volume down because of harshness, perpetual motion eventually.

When modded, things are way better, but it remains something unnatural, between the overall warm balance and this metallic tone in the high mids that's still there, even if less pronunced.

In the end, I do prefer my brave ol' SRM-1/mk2 Pro. Obviously it's no BHSE (bass, details, soundstage, impact, whatever), but it's consistent, and there's nothing disturbing in its presentation.

Ali

Edited July 22, 2017 by Ali-Pacha

[mypasswordis]

I just looked up the SRM-1 Mk2 schematic and it looks a lot like the 727 and most of the other Stax amps of the past 30 years, minus the output stage? Kicking myself for not hearing Ivan's 727 now...

[spritzer]

They keep polishing that circuit.  Funny to see if move from SRM-1 Mk2 to SRM-3 to 313 to 323 etc... 

[JimL]

Yeah, basically the same circuit, the only thing that changes is the outputs - transistor vs tube, resistor load vs constant current load...

Edited July 24, 2017 by JimL

[spritzer]

So I've spent some time with the T8000 and my impressions haven't really changed.  I've gone through a large portion of my collection with it and I sure as shit wouldn't use it with the modern Stax stuff.  With 009's this is simply ear rape at any volume above a whisper.  L700's as well though they are just generally sucky over all with any amp.  The L300's just sound a bit brighter than usual and a bit dull which they normally do. 

With the 007 collection it's again a bit dull, lifeless and bright.  Sounds have this annoying sheen to them which really shouldn't be there with the supremely neutral 007's.  I also dug out the SR-Omega with the new leather earpads and same shit.  Compared to even the cheap KGSSHV that is in development, it just lacks life.  The soundstage isn't expansive enough and things are just cobbled together.  The midrange lacks the presence it should have and the bass is just flat.  There isn't enough texture and depth to it. 

I tried pretty much every Lambda ever made, SR-X Mk3 Pro, Sigma Pro and a pile of others but it's always the same.  This amp is just lacking, no way around it.  I would be annoyed with it if it cost 3k$ but for 6K$ I'm furious. 

Lastly, this thing sound awful cold.  I normally just let my gear run 24/7 but with anything tube based I turn it off and I first though it was broken when I heard it cold. 

[Ali-Pacha]

Didn't listen to it but yeah, I've read a french review saying it's not that different from stock 727...which is to my ears compressed dynamic, metallic / harsh tone and bloated bass. Too bad though.

Ali

[kevin gilmore]

my opinion is that it is very close to a 717. definitely sounds different from a 727. 

[spritzer]

Yup, very close to the 717 from memory, nothing like a stock 727. 

[DefQon]

The T-8000 is $7600 AUD.

I can buy a BHSE with this amount. 

[purk]

Stax saw what Hifiman is doing to a highend headphones market, thus, they decide to do the same.  I really hope their new flagship will not be over 10K.

[catscratch]

... and this is why I don't buy the whole "if it's overpriced, just don't buy it" argument. If one manufacturer does it and gets away with it, it sets a precedent, and soon enough everybody's doing it. Letting market forces decide isn't always good for the enthusiast.

On the other hand, don't Stax have a history of setting ridiculous initial prices only to lower them somewhat years down the line? I recall them quoting well over $5k for the 009 initially in the States.

FWIW I quite like the 717, but I paid $800 for it. It has a nice warm sound but there is a slight metallic edge to the highs, and if a $6k amp had similar problems, I probably wouldn't find that acceptable.

[spritzer]

With Stax, the price anywhere but in Japan will fluctuate for natural currency reasons so Stax prices never change.  The SR-Omega was 180kYen in 1993 and only the 007Mk2 was increased to 192KYen in 2007.  Hello zero inflation...   

As for the whole "flagship" business, it is just silly.  I fully understand the whole issue of making something better can turn out to be really expensive but this stuff just isn't better.