The Stax Thread III

[Tinkerer]

 
Actually, it depends on some degree on how loud you listen.  I have a friend who has a modified SRM-T1 - mostly improved wiring, and input sockets, new PS caps and Goldpoint attenuator, although he may have done some other things, and it sounds pretty good driving his SR007 Mk I.  Not as good as my SRX Plus (we compared the two), but not too shabby.  Now, if you crank it up, the difference gets bigger the louder you play it - the T1 will poop out much sooner due to its output stage.
 
People say the SR007 is "hard to drive."  The truth is, there isn't much difference electrically between the SR007 and, say, the SR009.  In fact, Stax specifies the SR007 impedance at 170 kilohms at 10 kHz, vs 145 kilohms for the 009 (and the L700, for that matter) at the same frequency, so electrically the 009 is a bit harder to drive (lower impedance).  However, the SR007 has a few dB less output in the 2-4 kHz region than the SR009 (take a look at Tyll's measurements on the InnerFidelity website).  The result is that for the same music input, the 007 sounds less loud than the 009, so to get the same subjective loudness you have to crank up the volume, which stresses the amp more - remember a 3 dB change in volume, which isn't that much, requires double the power.  Doubling the loudness requires roughly 10-fold the power.  So really, the only way to know whether  the 007 will work for you is to try it with your amplifier.

 
IIRC the reason people say the SR-007 is hard to drive is that it needs a very good, very linear power supply to get the upper freqs to behave properly. I do know one of the main differences between the SRM-727 mod, SRA-12S mod, and the KGSSHV I had was the treble. Stuff like the old SRA never had any problems delivering the bass, but the STAX brand amps definitely sounded darker on the whole.
 
If the original reason I remember is true, it's mainly down to the PSU. Which I guess goes back to how people used to say the output stages of the original KGSS and the 717 are pretty similar. But the KGSS has the regulated power supply.

 

[astrostar59]

Thanks for your comments. To put things in perspective the dial on the T1 is numbered to 10 and I listen at 3 and it is plenty loud for me. I know volume is just one factor in evaluating the effectiveness of a driver but I don't think there would be any problem getting a 007 loud enough.

It depends on the line level you put into the amp as well. Some pre-amps pump out max 30v so the Stax amp will be overdriven if you go beyond say 12'oclock maybe less.
 
When I had the SRM-717 with my 007s MK2.5s it was ok at normal levels, but the sound balance changed as you pump up the volume on dance and full range music. The bass drops away and gets loose, the treble harsh and mids forward. I understood that as running out of current. If something else fair enough, but what I heard made me want to search for another amp.

 

[bosiemoncrieff]

What Is the best ( commercial or DIY) transportable AMP for a SR009. ( battery operated will be even better so that I can use It In my garden ?

I can't carry my BHSE every week-end to my country villa and me and my dogs would like to improve on my curent transportable battery operated audio system...

Just get another BHSE

 

[mulveling]

Bro, do you even BHSE?

 
Purk and I have both waffled a lot about the sale of his BHSE to me, and lo -- it finally happened. I'm going to have a LOT of fun getting familiar with this amp over the next several weeks. Consistent with my prior impressions, this is NOT a warm amp -- and the resulting sound is not going to be for everyone, when paired with 009 or L700. But for me that's OK because the sound of this amp is still exceedingly natural and tonally dense (beautiful midrange that I can't seem to find replicated in any SS amps). Treble quality is astounding, though to be fair there is a lot of energy there (call it sparkle, or ping, or what have you). Certain details and instruments are leaping out of the Stax headphones like never before. And there's gobs of impact down low  (I didn't know the L700 had that much wallop in them). The BHSE sounds more dynamic and lifelike than my other amps -- almost shocking in its realism. Tons of "wow" factor. Soundstage is exactly to my preference -- large but not too large (I don't care too much for that anyways, e.g. R10 which is also weak in bass/impact/dynamics, or HD800 which is bad in everything but soundstage size), but with awesome 3D/holographic placement and depth.
 
This is the best I've ever heard the L700 (note: I have't tried the L700 out of Purk's DIY T2) -- amazing dynamics/impact, and the maximum detail you're going to get out of those headphones. But again, there will be too much top-end energy in that pairing for some. The 009 are of course, even better than the L700 in every way. And though I still prefer the 009/BHSE over 007/BHSE, the 007 Mk I is an absolutely classic pairing here. The 007 w/ BHSE presents a sonic balance that will have universal appeal -- I'd be shocked (and quite honestly offended) if anyone didn't absolutely love this pairing. The warmth of the 007 Mk I is perfectly matched by the BHSE, which is really a credit to Justin's design skill, as that was the best Stax headphone available at the time of BHSE's prototyping. 
 
I do most of my critical listening at fairly loud levels (probably what some of you would consider VERY loud), and this likely accounts for some of why the BHSE sounds so much more detailed and uncompressed compared to lesser amps. I also don't listen to traditional "old audiophile" fare. Lots of hard rock and metal. 
 
I'm running Holland/Amperex brown-base EL34; xf5 types -- just got my own quad in and biased up nice, so Purk can now have his set back
I haven't done any tube rolling in the BHSE yet, but went through lots of EL34 variants several years back with speaker amps -- and from that experience, I'm not even going to bother with the Russian variants. Most Russians sounded bright as hell and generally had various issues in the treble. Not a big fan of playing the "when will this tube blow up my amp" game, so Chinese and JJ tubes are absolutely out of the question (for that matter Russian tubes aren't confidence inspiring either, as I had an Electro-Harmonix KT90 short out and scorch the circuit board in my Rogue Apollo monobloc). Vintage Amperex and Mullard tubes, even with visibly scorched plates and burned-off getters, seem to just keep going. 
 
Source is a Yggy though the spdif input -- good pairing. The BHSE seemed a bit brighter through the NAD M51, back when I heard that pairing; a bit too much. Someday I need to pull over my TT setup, since that should be beyond even the Yggy (Clearaudio Innovation w/ Koetsu Platinum; currently hooked up to big Tannoy Canterbury speakers). I love Koetsu cartridges almost as much as I love Stax headphones. It almost seems taboo to put the two together; that might be just too much sonic pleasure for me to handle.
 
Early indications are that this will easily be my favored amp. But again, some folks will wish for a warmer pairing with the 009 or L700. To recap, here are the other amps I've got around (it's long past time to cull the herd):

1. KGSShv Carbon - Golden Ref HV, but not LV supply. Great all-rounder, and what I consider quite neutral, but the tone isn't quite as natural and sweet as with a great tube amp. 
2. DIY hev90-balanced - With Mazda tubes (chrome plate 12ax7), it sounds like what I wish the KGST had sounded like. Perfect amount of warmth for 009 and L700. Not as good technically as the Carbon, but maybe close enough given its strengths. 
3. KGSShv 500V IXYS - A great general-purpose KGSShv, but of course it falls notably short of the Carbon.
4. KGSShv 450V Sanyo - Warm, very warm. This is as warm as you are ever going to hear the 009.
5. KGST - Basic KGST build with no frills; good pairing with L700. Also very good with the 009, though that headphone deserves a much better amp. 

 
And as everyone should know by now, this amp is stunningly beautiful in person. A lot of gear gets high accolades for build quality, but very few items genuinely deserve it. The BHSE is special. The BHSE makes everything other than my Tannoy speakers and turntable look low-class, and upon close inspection, even those two fail miserably against the BHSE's impeccable build standards. I can't believe that Justin is able to sell these for what he does. In the traditional hi-fi world, manufacturers (*cough*, e.g. VAC) would markup the price of the RK50 pot alone to an amount in excess of the entire BHSE amp.
 
Final note -- I believe that a proper DIY T2 build beats all. It's impossible to beat that. And it's warmer sounding than the BHSE, too. But good luck landing one of those (I probably never will). I'm also aware that I'm not helping my cause by continually posting how amazing it is, without already having one myself. But at least the BHSE is far prettier
 

 

 

[JimL11]

   
IIRC the reason people say the SR-007 is hard to drive is that it needs a very good, very linear power supply to get the upper freqs to behave properly. I do know one of the main differences between the SRM-727 mod, SRA-12S mod, and the KGSSHV I had was the treble. Stuff like the old SRA never had any problems delivering the bass, but the STAX brand amps definitely sounded darker on the whole.
 
If the original reason I remember is true, it's mainly down to the PSU. Which I guess goes back to how people used to say the output stages of the original KGSS and the 717 are pretty similar. But the KGSS has the regulated power supply.

Well, again, when you turn up the volume, it stresses the power supply more, so everything is more prone to misbehave.  With an unregulated supply, there is more intermodulation of the bass with everything else, and it's worse the more you crank it.  A regulated PS is ALWAYS beneficial, and the louder you play the bigger the difference.  The reason the 007 seems harder to drive is that you have to turn up the volume about 3-4 dB to achieve the same subjective level, so in that sense it is "harder" to drive than other Staxen.  Then in addition, in all the Stax tube amps, the output stages use resistor loads so the majority of the signal current goes to driving the output resistors and the headphones are left with the scraps.

 

[jjacq]

What KG amp would be a reasonable buy for the L700? Would the KGSSHV be a good match for it? The DAC is a gumby.

 

[mulveling]

  What KG amp would be a reasonable buy for the L700? Would the KGSSHV be a good match for it? The DAC is a gumby.

Maybe with a warm 450v Sanyo KGSShv -- I actually haven't tried that pairing, though I have both. An L700 isn't going to be most optimal match with most KGSShv's in my opinion; I'd actually prefer a KGST there -- and I generally prefer KGSShv over KGST for the 007 and 009 (I feel that the KGSShv is a better amp than my KGST, overall). It's not like the L700 sounds bad through a KGSShv, though. Gumby should be a good choice; it's reported to be a bit warmer than Yggy, which should help you.

 

[bmichels]

I HAVE MY BHSE  at home ))))  I just brout it back from CanJam.  It is the Black unit that HeadAmp was using for the demo this WK in London...  

 
 
 
 
 
I also spoke with Dan from Mr Speaker who also own a BHSE that he uses to develop his next Electrostatic headphone that may ship early 2017.  
 
He suggested I try the Siemens EL34 that he personally use in his BHSE to get a softer high.  dos someone know and experienced those Siemens tubes ? 

 

[mulveling]

  I HAVE MY BHSE  at home ))))  I just brout it back from CanJam.  It is the Black unit that HeadAmp was using for the demo this WK in London...  

 
I also spoke with Dan from Mr Speaker who also own a BHSE that he uses to develop his next Electrostatic headphone that may ship early 2017.  
 
He suggested I try the Siemens EL34 that he personally use in his BHSE to get a softer high.  dos someone know and experienced those Siemens tubes ? 

Very nice!! 
Siemens EL34 are typically from communist East-Germany. They look better made than most Russian tubes (actually, cosmetically they look exactly like a better-built Electro-Harmonix EL34), but not as good as the classic Mullard/Amperex EL24. I had a quad off Ebay years ago that blew a tube (cherry red plate, then fuse went) within the first 30 sections of listening (restored vintage speaker amp; not a BHSE). Well, you could say that's Ebay tube buying. But Mullards do have a better reputation of reliability. And from those 30 seconds -- the Seimens sounded good, but Mullards are warmer.
 
Vintage Mullard EL34 are going to be the gold standard of sonic warmth and reliability. The Holland versions are made from the same Mullard tooling, and at least as good, but reportedly sound a bit less warm / more neutral (I've used both but haven't compared in the same amp). Don't stress so much about the xf codes and base types -- just get a good testing couple of pairs. 

 

[purk]

 

Bro, do you even BHSE?

 
Purk and I have both waffled a lot about the sale of his BHSE to me, and lo -- it finally happened....
 

I sure miss that amp already.  I had one of the biggest seller remorse ever but then again it will be cherished by Mulveling ....so  it is all for a very good reason.  DIY T2 will get more used now.

 

[LaCuffia]

Anybody have an opinion on a SR-404 Limited Edition v. the L700?    The former is obviously rare, and has a good reputation.   Just looking for a brief opinion on whether the L700 is worth double the price.

 

[Blackmore]

To me, both are worth to own, where 404LE llike high quality monitor and L700 are all about fun, but dont get me wrong, when I say fun, I also mean highest quality one

 
 
404LE were the reason why I sold my HD800. In terms of piano and orchestral work reproduction they just amazing, but they can do more, just in very different way than L700, which are more upfront, full body with amazing bass sounding ear speakers, I simply love them with any music, but classical I love 404LE more, piano is stunning, imo.
 
 
 
Quote:

  Anybody have an opinion on a SR-404 Limited Edition v. the L700?    The former is obviously rare, and has a good reputation.   Just looking for a brief opinion on whether the L700 is worth double the price.

 

[LaCuffia]

Thanks...so the L700 seems to be the more "musical" option and the LE the more analytical and detailed.   Is the bass on the LE that much less present than on the L700?   The idea of an electrostatic earspeaker with a great bass response like they say the L700 has is very intriguing.  I am not a bass head by any means, but don't mind a little heft in that department without it being too colored. 

 

[dubharmonic]

  Yama is the U.S. distributor for Stax.  It's never a paticularly satisfying experience buying from them.  Phones aren't answered, voice mail is full, e-mails get answered 10 days after the original was transmitted.  I think they're a very small operation.  However, when they have given me a approximate delivery date, I have received the items on time and in good order.  You need some patience with them.  As I said in my earlier post though, demo first.  Electrostats aren't everyone's cup of tea.   

Welp, impulse won over reason, and against my better judgement there's a set of SR-L500s being delivered today. How much time does a new set need to charge up? How many hours until they reach their 'final form'?

 

[astrostar59]

Hi Mulveling
I am glad you like your BHSE. Another set of NOS tubes coming your way from me soon as well. Enjoy.
 
BTW would you say the tube upgrade from stock is worth the cost v SQ hike? I noticed quite a difference in smoothness especially in the treble on David's BHSE with the 009s. So I did prefer the sound with those NOS Mullards in. The amp with stock tubes to me sounded brighter.