The Stax thread

[thrice]

Quote:

Originally Posted by Carl While fiddling around with them I managed to give myself the first true electric shock I've gotten from electrostatic headphones. It really hurt. This just ain't my day.

Yikes....gotta be careful man, 580V is nothing to joke about. Hope everything is going well with the 4070

 

[Carl]

Quote:

Originally Posted by thrice Yikes....gotta be careful man, 580V is nothing to joke about. Hope everything is going well with the 4070

I think it was from the audio signal, not the biasing. There seems to have been some current behind it.


Anyway, here's a Japanese article about the industrial designer for the SR-007 and SR-001.
http://www.axisinc.co.jp/talkshop_f/81/81talk01.html

 

[wualta]

Could it have been the Mitsu amp going psycho?

 

[Carl]

Quote:

Originally Posted by wualta Could it have been the Mitsu amp going psycho?

That thing's so servoed it couldn't even fart without some protection circuitry kicking in.

 

[Carl]

Comment on 2ch:

141 :名無しさん@お腹いっぱい。 :sage :2006/10/27(金) 20:13:36 (p)ID:W0L4+f8u(4)
SRM-727A
●出力段を無帰還(NON-NFB)大電流エミッタフォロワー・Aクラス増幅回路を新開発して
搭載しました。よりダイナミックで躍動感に溢れた音質を実現しています。

えぇぇ~、これは全く予想外の変更だわ。


Translation a la Carl:

"SRM-727A
A newly developed high-power, no negitive-feedback, Class A, emitter-follower output stage has been added, allowing for improvements in the timbre/bloom (?), dynamics, and tactility.

Wow!! This is a really unexpected change"


148 :名無しさん@お腹いっぱい。 :sage :2006/10/27(金) 21:24:32 (p)ID:W0L4+f8u(4)

>>146
そうだと思います。でエミフォロなんでローカルNFBはばっちりかかってると。

終段をオーバーオールNFBから外しちゃったせいと思われる、歪率の上昇が見られますね。

717:0.01%以下 100-10kHz/300r.m.s.V出力時
727A:0.01%以下 100-10kHz/100r.m.s.V出力時

聴感上、全く問題のないレベルの上昇とはいえ何でNFBループから外したんだろう?

・特に高域のダイナミックレンジの大幅な拡張を実現。

とあるのを真に受けると、エミフォロ -> イヤスピ間のシリーズ抵抗値を小さくしてスルーレート
を上げ、そのままでは位相余裕が確保できないから、終段だけ切り離したとかかな?
ちょっと興味深いですね、今度シミュってみねば。


"To Mr 146:
That's what I think. With an emitter follower local NFB is a perfect match.

The removal of feedback from the output stage has led to an increase in the overall distortion level.

717:Less than 0.01% distortion between 100-10kHz @ 300rms volts
727A:Less than 0.01% distortion between 100-10kHz @ 100rms volts

Will it sound better with what is unargueably an increase in distortion resulting from the removal of the feedback loop?

•Especially, will it allow for a large increase in the dynamic range in the treble region?

Because the series resistance between the emitter follower and the cans is less, it's likely the slew rate has been improved, but the way it is might lead to phase errors (?). It's all very interesting, isn't it?"


None of my translation should be taken as gospel, but I guess it's better than using Google or Babelfish.

 

[wualta]

Quote:

Originally Posted by Carl That thing's so servoed it couldn't even fart without some protection circuitry kicking in.

Something's weird, then. The 4070s couldn't just make popping noises on their own sayso... [continues thinking]

Have you tried emailing Stax?

 

[Meyvn]

The SRD-7SB Mk II is here! The Stax have never sounded better. I honestly think I would consider these superior to the SR-007, at least from memory. They're more detailed, and at the same time more well rounded, and more forgiving of bad recordings. It's really an incredible headphone; an incredible value, especially. I'll have to hear the Omega II again to compare, but I doubt it'll beat this sonically in my estimations, especially with this transformer. By the way, I didn't notice as huge a difference as I was lead to expect when comparing the pro bias to normal bias on this same transformer; I did however notice a big jump going from the SRD-6 to the SRD-7 Mk II. I'd like to hear the SR-X Mk. III again to see if I like it better on this transformer. It's just much better quality than that old 70s box.

On a side note, on the Aleph 3, if I hook up the spade lugs to the binding posts for the K1000, and then stick in the banana plugs for the SRD-7, will it hurt anything? If so, would it hurt anything to have just the K1000 extension hooked up, but not the K1000?

 

[spritzer]

The SR-007 totally creams the Signature in every thing but value IMHO. They get much better with a better amp, the brightness is tamed and that damned etch goes away. Watch out for their extreme sibilance or your ears might fall off

The transformer might be lossy enough to mask it though which is a very good thing

 

[spritzer]

Quote:

Originally Posted by Meyvn On a side note, on the Aleph 3, if I hook up the spade lugs to the binding posts for the K1000, and then stick in the banana plugs for the SRD-7, will it hurt anything? If so, would it hurt anything to have just the K1000 extension hooked up, but not the K1000?

If there isn't a short anywhere this shouldn't be a problem

 

[Meyvn]

Quote:

Originally Posted by spritzer The SR-007 totally creams the Signature in every thing but value IMHO. They get much better with a better amp, the brightness is tamed and that damned etch goes away. Watch out for their extreme sibilance or your ears might fall off The transformer might be lossy enough to mask it though which is a very good thing

They sounded sibilant to me on 230V with the SRD-6, but I don't get any of that feeling (or the etch, really), with the SRD-7 Mk. II. Keep in mind, though, that my main headphone is a K1000, and yours is an Omega II. We probably have completely different perspectives on just what we want in a headphone. Also, I have NOT heard the Sig and the SR-007 on the same system at the same time. Hopefully I'll remedy that soon, and when I do I may completely retract my opinion. But from memory, what I said stands.

 

[jjcha]

Make sure you hear the O2's on a worthy amp. I can't count how many times I tried them on a 007t or 717 and was never impressed. Only until did I hear them on a KGSS did I think they were okay/worthy/good and the ES-1 just brought it to another level. Now all these were just brief impressions, but only recently have I come to appreciate the O2's as really being top notch (though damn it's got a lot of bass for my preferences....

)

Best,

-Jason

 

[Meyvn]

Quote:

Originally Posted by jjcha Make sure you hear the O2's on a worthy amp. I can't count how many times I tried them on a 007t or 717 and was never impressed. Only until did I hear them on a KGSS did I think they were okay/worthy/good and the ES-1 just brought it to another level. Now all these were just brief impressions, but only recently have I come to appreciate the O2's as really being top notch (though damn it's got a lot of bass for my preferences.... ) Best, -Jason

I heard them on a Headamp KGSS, and that's it thus far.

 

[spritzer]

The O2's are IMO the kings of the stats with only my tweeked and recabled SR-X/Mk3's coming in second on pure prat and fun alone. They are awsome out of the Blue Hawaii, deep tought bass and extended highs with a glorius but slightly shut in midrange. Not bad for a 31 year old design

 

[ironbut]

What's the record for the highest number of posts in a thread around here!

 

[Meyvn]

Quote:

Originally Posted by ironbut What's the record for the highest number of posts in a thread around here!

If I recall, one of the game threads has got it. As far as 'real' threads, Curse You is pretty high up, as is the K81DJ appreciation thread. Both of those have more than twice the posts of this one. This is a good'un, though; full of useful and hard to come by information. It's almost like having our own Stax forum.