STAX SRM-717 vs. SRM-007t?

[Vertigo-1]

So how do these two compare? BTW if anybody can regurgitate what the Stereophile review of these two amps said, it'd be GREATLY appreciated, seeing as for some stupid reason I never picked up that issue.

And what tubes are used in the SRM-007t? Any problems with tube hiss?

 

[DanG]

From what I recall, Stereophile's reviewer (was it Kal Rubinson?) preferred the 007, calling it more "musical" (Stereophile's favorite cop-out term). I think that Kevin Gilmore prefers the 717, but maybe Senor Stax would prefer to chime in himself.

 

[TerriblySorry]

My SRM-007t still has the stock tubes fitted. I couldn't tell you what they are, but I can say they don't hiss.

 

[yarinkel]

I compared them during 2 weeks them before going for the 717, but it was 3 month ago, so remember that my comments might be biased.

Both are very well built. The volume control is heavy, smooth and feels solid. There is strictly no precedence of one channel on the other, even at ridiculously low volumes. They both look ugly (this distinguish "I have been stolen on a Russian nuclear submarine" look of Stax), but the sound is near perfection on both.

The 007t had 2 connectors for pro Stax headpones plus one for normal (older Stax headphones). The 717 only has the 2 pro connectors, so if you have one of the oldest headphones you have to choose the 007t. They both have cinch and XLR input.

The 717 runs very hot for a solid state amp. The 007t is very hot too, but thats quite normal for his 4 tubes. They both use around 50 Watts.
I only tried them with balanced input, not the cinch, and only from a digital source. The headphones used where the Omega II and the signature 404.

Basically, they are very similar in sound I found. The 007t doesn't actually sound very "tubby" for a tube amp, and the 717 is smoother than other solid states I'm used to. The 717 uses FETs who are closer to the way tubes works than regular transistors, maybe thats why. Howewer, after extensive listening sessions I found out that the 007t had a slightly "grainy" sound, a little bit smoother but not as clean at the 717. I had the impression that the 007t had a bit more dynamics, i.e., I could listen to the music at a slightly lower volume before reaching the level where I got an impression of "flatness" in the music.

You can both turn them at full volume (with a blank track on a test CD), and you don't hear the slightest hiss. The Stax systems are totally insensitive to mobile phone interferences too, I noticed, not like my X-Can/HD-600 combo.

I liked the 007t more for my old recordings (doors, simon & garfunkel, ...), but for the biggest part of my collection (classic, electronica, drum & bass, ...), I preferred the perfect (if there is such thing sound of the 717. Hence my choice.

However, as I said before, the differences are quite subtle. My advice would be to try them for an extensive period of time, they are just too expensive to make a mistake.

 

[yarinkel]

Oops, I forgot the last question. The 007t uses the modern 6FQ7/6CG7 (4 of them).
When you switch it on, it preheats for ~20 seconds. Not much warming up effect however on this amp, during the 1st hour it might become slightly smoother, but then, I found no further improvement.

 

[Vertigo-1]

yurinkel, thanks for that detailed reply! So there isn't much tonal difference between the two amps...which is what I figured from the research I did on the two, which coincidentally there is very little info on. There are huge reviews on one or the other, but the only detailed review of both amps at once that I know of is the Stereophile one. Until yours.

Did you happen to notice any differences in sound decay, extension, bass impact, soundstage width? One of the major differences I heard compared to solid states using my current Audiovalve RKV is that the treble, while smoother than a typical solid state as expected, also extends further...more extension, more decay to cymbals. Strangely I'd expect this to be a premise of solid state amps, to provide the more detailed sound. The RKV also has MUCH more bass than most amps I've tried, which could be the tubes, or its massive power supply. The RKV is an OTL design though, and stuff like this usually is OTL territory, along with the ever massive soundstage. Did you notice any differences of this sort while comparing the two?

 

[RickG]

Hey Vertigo,

I don’t have a scanner so I copied some of the text from Jonathan Scull’s review of the Stax SR-007 Omega II phones with the 007t and the 717 in the July 2001 issue of Stereophile:

“The 007t was a bit more immediately colorful, with softer and rounder bass and not as extended at top or bottom- but it was sweeter and more engaging.
The solid-state 717 also displayed a full tonal palette: its bass was tighter, its highs more extended and yes, less sweet. But it was good in the midband which was something of a welcome surprise.”

“The solid-state 717 amp always sounded a touch more obscuring in the midband, while remaining smooth and rather attractive nonetheless. That was accompanied by my tendency to crank the tubed unit louder. This was more than a question of matching volume levels: there was something about the tonal balance that “asked” for it.”

“The 717 had somewhat more body and palpability than the tubed 007t, with an attendant loss of…elegance? I noticed that especially with The Modern Jazz Quartet (Japanese AMCY-1165). Flipping back to the tubes, Milt Jackson’s vibes sounded phenomenal: more immediate and full of color. That’s what cut it for me, big-time. Since you’re that “close “to it all, it better sound its best, and it better be Technicolor if the ‘phones cost as much as these do.”

“Bizet’s Carmen Suite No.2, performed by Seiji Ozawa and the Orchestre National de France (EMI CDC 7 47064 2) came off as such a sweetie it made my limbs dance with pleasure, and more so through the tubed 007t. There was necessary warmth in the midrange that gave it life with the tubes. I need life. I also found that the tubed 007t had a more finger-snappin’ sense of timing that didn’t develop so fully with the 717, and that led to some emotional, emotive quality that’s hard to quantify but nonetheless
unmistakable.”

While referring to the 717 as “fast and athletic even at low volumes” and having a “lovely midrange”, Scull preferred the 007t. Although I have never had the pleasure of listening to the 717, from what I have read in various sources, I feel I could easily live with either amp. Scull ends his review this way:

“Soften it up slightly by going for the SRM-007t’s tubes, or keep your extension and a lovely midrange with the solid-state SRM 717. A matter of taste, pure and simple.”

 

[RickG]

After reading your last post, Vert, you might be a prime candidate for the 717. From what I understand, there is a little more extension on both ends and maybe a tad extra speed with the solid-state. However, I don't hear the grain mentioned by yarinkel on the 007t.

yarinkel said
Quote:

They both look ugly (this distinguish "I have been stolen on a Russian nuclear submarine" look of Stax), but the sound is near perfection on both

I prefer to say the Stax amps look conservative .....like they mean business (and they do!).

 

[Vertigo-1]

[size=small]Thank YOUUUUUUUUUUUUUUUUU Rick G!!! [/size]

I was praying somebody would take my hint and be willing to take the time to type out some parts from the Stereophile review.

LOL, Scull managed to make the 717 sound pratically exactly like the 007! Ugg.

 

[Rpell]

Quote:

The 007t doesn't actually sound very "tubby" for a tube amp...

The 007t is actually a hybrid amplifier, with a tube output stage and a FET input stage.

 

[Vertigo-1]

I noticed in pics that the 717 doesn't seem to have input selector buttons on the front panel, while the 007t does. Is this yet another feature that's on the 007t, but not on the 717, like the extra headphone output for older Staxs?

And now that I think about it, the 007 sounded grainier? That's interesting, as that's usually solid state territory as well.

 

[RickG]

Vert, you're right about the outputs. Both amps have two Pro Only five-pin sockets with 580V polarizing voltage. Only the 007t has the six-pin "Normal" type with a 230V voltage.

 

[yarinkel]

First of all, RickG, thank you for taking the time to type parts of Stereophile's review. It is always informative to see what professional reviewers think about equipment you own, where you agree, where you differ and so on.

Vertigo-1 , what a mean by grain is a way of presenting the music, a kind of inaudible texture, that made sounds like electric guitar, triangle, and trumpet much more enjoyable to mee. However, on electronic instruments, violins and piano I preffered the 717's extremely clean sound (closer to reality to my perception).
I can imagine that some people could find the 717 aseptic.

Contrary to Scull, I didn't notice a difference in the extension of trebles, actually the 007t suprised me by how far and clean he went into trebles. For the bass, I remember the 717 having a bigger extension, yes, but the 007t seemed a bit more dynamic.

By the way, a friend of mine who is into hi-fi as well tested both amplifiers while they were at my place, he ended up telling me "sorry, but I can't hear any difference". This was my first impression too, but after a few hours switching those heavy XLR cables back and forth, I started noticing those differences in character. Subjectiveness ? Might be, but as long as it is consistent...

 

[RickG]

Quote:

Originally posted by yarinkel actually the 007t suprised me by how far and clean he went into trebles.

My feelings, exactly. I expected the 007t to excel in the mids and be somewhat superior dynamically due to the nature of tubes, but I was quite surprised at the amazing top end clarity and range.

 

[Vertigo-1]

Hmm so that grain was that undescribable but utterly desireable tube texture then? That's cool.

I guess I'm worried that the 007t might truncate the sharpness of certain instruments, such as cymbals. It comes with the tubes I guess. My RKV while extending treble more also softens it up so that cymbals lose their steely sheen. It'd be nice if I can get extended treble without losing that sheen as well. I can understand that special unexplainable midrange since I'm experiencing it too with the RKV, and wish that could be present without losing the upper treble sheen. Obviously the true tubed experience is different from injecting more midrange into the music at the cost of everything else which is what low end tube amps do IMO, or simply smoothening the midrange, which sounds like what the 717 does.

Now on the other hand...I'm speculating that the Omega II headphones are utterly revealing, so by themselves alone, they should be able to show the absolute treble extension contained in a recording. That leaves how and what the amp lets through to the Omegas.

But here's another case...with instrumental New Age music, the 717 sounds ideal. Leave all the extensions and details in. But with Asian pop (which consists mostly of slow ballads as far as I'm concerned), it sounds as if the 007t would be better. Injecting that special midrange to romanticize the female voice, and also softening up sibilants. Here's a case where I could imagine the 717 fully unleashing the sibilants most Asian pop contains, as the language itself tends towards the sibilant side.

Me =

over these two amps...