The Stax Thread III

[astrostar59]

When I had the SRM-717 I did try it for a while with a good pre-amp in front of it (Audio Note M3 tubed unit) and then direct from my Server. Thing is is you have 2V and the standard output impedance of line out there is NO point in adding a pre-amp to the front of any of the Stax amps IMO. They are designed to run off a line out from a CD plater or DAC, and not input more current. A pre-amp can output 30v depending on the design so way over the specs of any Stax amps input and may damage the amp if you feed it too much.
 
I also tried using volume bypass on the 717 and operating digital volume in Audirvana+ but it kills the sound as in digital in that application lower the output = less resolution.
 
You could try a passive and miss out the amps pot but then that will add more interconnects and move the pot further away from the amp circuit so may not help. Make more sense to fit a better pot to the Stax amp.
 
It is physically impossible to get more out a set Stax amp design without changing the amp insides (mods). So if the sound is not to your liking, and assuming the HPs or source are ok to you, then you need to change your amp.
 
Hope this helps.

 

[bmichels]

Still No news about this neat Stax SRM212 DAC/AMP ?

Has anyone seen It since the proto was shown at CES 2016 In February ? ( first apparence at CES... 2014 ! )

 

[Tinkerer]

I've always wondered, how much does a good buffered VU meter affect sound in an amp like that? I've been thinking about putting one for each channel in my circlotron build.

 

[BoyNamedSue]

 
No, it won't do anything for the mid / upper ranges. The port mod from what I have read addresses the bass bloat in the lower ranges. The mod is basically taking off the leather cups (easy) and plugging the port hole with blue tac) (easy) the putting the cups back on (which I found tricky on my MK2.5s).
 
Maybe look at your source as the 007 (any version) is not renowned for mid / treble glare TBH. What DAC and amp are you using?

 
Can the port mod be done with MK2.5? I thought I read somewhere that it was only for the MK2's. If so, I may give it a shot as I have found the bass to be bloated off the WES and 323s, but not the carbon. Thanks in advance.

 

[astrostar59]

   
Can the port mod be done with MK2.5? I thought I read somewhere that it was only for the MK2's. If so, I may give it a shot as I have found the bass to be bloated off the WES and 323s, but not the carbon. Thanks in advance.

The port mod can be applied to any MK2 to current as far as I am aware. I have the 007A 2014 and don't fell the need for the port mod, whereas with my 2.5 Black units I was never happy with the bass control (but I didn't mod them).
 
TBH you are never going to get great control of the 007s drivers with a WES or 323. The WES has history (dig around to find out). I had the 717 and it was ok but still didn't control the 007s very well (ran out of dynamics and bass control). Yes the Carbon, but more money.... I am not convinced the 2.5s can ever sound 'right' IMO. Mine didn't  and were too veiled and slow, too tubby in the bass, very un Stax. The current 007A however is a different story and as good (maybe bit more alive) than the 007 MK1. All in my listening test, ImO and others may / will disagree! Hard hat put on running away now as I speak....

 

[Michgelsen]

  A pre-amp can output 30v depending on the design so way over the specs of any Stax amps input and may damage the amp if you feed it too much.

 
The common Stax amps have a rated maximum input level of 30V.

 

[astrostar59]

   
The common Stax amps have a rated maximum input level of 30V.

Yes you are correct, missed that. If you look at the SRM1 manual it says connect to the record out on the preamplifier which is a pass through, no gain stage from the pre-amplifier.
 
Having a pre-amplifier stage in the chain where a standard 2v line out can drive the Stax amplifier without doesn't make sense to me. That extra gain stage will only reduce the quality of the sound by adding yet more components in the way. You are amplify thing signal to then reduce it back down again.
 
I did try both options, and aside from some tube warmth, the addition of a pre-amplifier reduced the speed and detail of the direct from source route.

 

[bmichels]

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...

 

[purk]

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...

Get the SRM-323S and one of this baby
 
https://www.amazon.com/MixMart-24000mAh-Laptops-Tablets-Smartphones/dp/B01HEPTD9W/ref=sr_1_2?ie=UTF8&qid=1471079604&sr=8-2&keywords=portable+110+power+supply

 

[Mp0wer]

Does anyone know if the SRM-252s driver unit can be by-passed, I want to get the SRS-3100 and want to use a different HP amp or am I stuck using Stax included amp.

 

[astrostar59]

Does anyone know if the SRM-252s driver unit can be by-passed, I want to get the SRS-3100 and want to use a different HP amp or am I stuck using Stax included amp.

Do you mean, can you buy the SR-L300 on it's own. You can. But you will need an electrostatic amp of some sort to power those (electrostatic) headphones.

 

[Mp0wer]

Do you mean, can you buy the SR-L300 on it's own. You can. But you will need an electrostatic amp of some sort to power those (electrostatic) headphones.

yes that answers my question, I didn't know you have to use a electrostatic amp..Thanks

 

[Quixote79]

you does not need a electrostatic amp if you use a transformer box
some says it also sounds true good

 

[JimL11]

  If I have a SRM-T1 and don't plan on upgrading the driver anytime soon since it's in good condition and am happy with it, what would be the better option in terms of performance - a L700 for around $1,400 or the SR-007a for $1,800 or so?    Just bearing in mind that my only Stax experience so far is with the 2170 system, and a SR-5 (that I used with a SRD-7 but now with the SRM-T1).  I know there are much better drivers out there, especially for the 007, but simply looking into whether it's worth the extra $400 to $500 to go above the L700.  I like a neutral sound, but probably a tad warm, with a full bass.   The most important factor on par with sound, however, comfort and weight.  How do the two compare in that respect? 

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.

 

[LaCuffia]

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.