[batfier]

that is really interesting that D50 sounds warm, which is very welcomed

The question is it powerful enough, to drive from example stax 007mk2, or 009s in case one wishes to upgrade to one those headphones later, or would the stax 353x be a better choice. I know many say stax 007mk2 needs a very powerful amp, so that is why i am asking.

D50 drives the 009 pretty well. i liked the darker voicing of the D50 with the 009.

but I returned two D50 units, as both had some hum in one of the channels, when they were warmed up. looked like a more general issue. but this was ca. 1-2 years ago. so I hope, that stax had fixed it in between.

furthermore the dac section was ok, but not the greatest I have heard and the unit runs quite warm.

the 007 is harder to drive. not sure if 353x or D50 is the optimal match here.

 

[talan7]

I’m new to electrostatic. I just purchased the Kaldas RR1 along with the Stax 323 energizer and have fallen in love with stats. I need some help. I’m interested in the SR-007 mk2. What’s the difference between the SR007a and the SR007 mk2? Is the SR007a the mk1?

 

[padam]

SR-007 MK2 (black) and SR-007A (silver/black) are the same headphones, except the colours to differentiate export vs domestic (although as far as I know, now you can order both colour schemes from anywhere as a special order, they have called the black version SR-007A BL in Japan)

The earlier SR-007 Mk1 is simply called SR-007 available in champage/brown or it was avaliable in champagne/black as an export model, also known as SR-007BL
Or if a brown SR-007 Mk1 gets a full service from Stax including a cable repair, they will probably replace everything - cable, arc assembly, earpads - with black parts, so it will look exactly like the SR-007BL as well.

 

[PointyFox]

The MK1 had a design issue that would cause stress on the cables and cause them to break with repeated flexing. Stax removed some material in the MK2 so the cables wouldn't be stressed, but this created a lack of seal and therefore bass. The Spritzer BluTack mod seals the area with a flexible material to restore the bass and seems to increase it further over the MK1. The MK2 also had a slight pad redesign to make the drivers sit further away. Recent MK2 headphones have apparently undergone a driver change that causes the headphones to sound more forward and are dubbed the MK2.9, which is the latest version and has a serial number beginning with SZ3. A few people say it sounds better to them.

 

[talan7]

The MK1 had a design issue that would cause stress on the cables and cause them to break with repeated flexing. Stax removed some material in the MK2 so the cables wouldn't be stressed, but this created a lack of seal and therefore bass. The Spritzer BluTack mod seals the area with a flexible material to restore the bass and seems to increase it further over the MK1. The MK2 also had a slight pad redesign to make the drivers sit further away. Recent MK2 headphones have apparently undergone a driver change that causes the headphones to sound more forward and are dubbed the MK2.9, which is the latest version and has a serial number beginning with SZ3. A few people say it sounds better to them.

Does the MK2 sound better than the MK1? Sounds like MK1 has more bass.

 

[PointyFox]

Does the MK2 sound better than the MK1? Sounds like MK1 has more bass.

I think it's subjective. I've read the modded MK2 has more bass than the MK1.

 

[gurbina93]

@RKarim

I have exactly the same issue but with a SRM-252S and L300. I am starting to wonder if it's the headphone... but since it's my first electrostatic I have no idea if I am pushing it to the limit.

Whenever I play any bass heavy or busy track and go past 2' on the volume pot, which I need to do due to the EQ I start hearing terrible distortion, clipping, crackling the same as you. Source is all FLAC 16-24 bit, I just EQ'ed a bit the bass +1 to +4 in the lower and mid bass region.

At first I thought the amp didn't have enough power to drive them to these lenghts.

Can't compare those specific energisers, but my impressions with my L700 Mk 1 with the ones i have......

252S is sure an okay starting point for what it was at the time I bought it.
SRM-1/MK-2 definitely steps up the detail vs 252S, though my particular unit sounds a touch bass-light and may need to be recapped due to age.
353X sounds the best of the 3 units I have. Have not heard anything else to compare it to.

Mjolnir of course has a great reputation in my eyes, and I wouldn't be afraid to try them but have no experience.

If you can find an SRM-1 cheap enough and in good condition? Yeah, my ears say it's a fairly substantial step up from 252S...and you also gain a "Normal" Stax output if you happen to run across vintage earspeakers 1 Pro output, and 1 Normal output.

@Pahani I saw you had or still have these amps, could you perhaps help us both if you run into the same issue with your L700?

I am questioning myself whether I should upgrade just the amp, the headphones or both... I just want to enjoy my music my L300/SRM-252S sounds wonderful on most of my music, but whenever a busy/bass-heavy track plays I just wanna rip-off my ears, I can't stand it.

 

[PointyFox]

My L700MK2 with KGSSHV doesn't distort even at relatively painful levels of bass. Have you tried reducing the volume to your DAC or the volume to the energizer and turning the energizer up? Might be clipping an input.

 

[OneOddPhoton]

@RKarim

I have exactly the same issue but with a SRM-252S and L300. I am starting to wonder if it's the headphone... but since it's my first electrostatic I have no idea if I am pushing it to the limit.

Whenever I play any bass heavy or busy track and go past 2' on the volume pot, which I need to do due to the EQ I start hearing terrible distortion, clipping, crackling the same as you. Source is all FLAC 16-24 bit, I just EQ'ed a bit the bass +1 to +4 in the lower and mid bass region.

At first I thought the amp didn't have enough power to drive them to these lenghts.


@Pahani I saw you had or still have these amps, could you perhaps help us both if you run into the same issue with your L700?

I am questioning myself whether I should upgrade just the amp, the headphones or both... I just want to enjoy my music my L300/SRM-252S sounds wonderful on most of my music, but whenever a busy/bass-heavy track plays I just wanna rip-off my ears, I can't stand it.

Are you EQing via Software? If so did you reduce the final Gain? It should be down about -5db to accommodate the +4 Bass boost, else you will get digital clipping (distortion).

 

[gurbina93]

@PointyFox thanks for the info, good to know these headphones can handle it.

Are you EQing via Software? If so did you reduce the final Gain? It should be down about -5db to accommodate the +4 Bass boost, else you will get digital clipping (distortion).

Yep, I set it to auto gain and it usually the final gain ends up in -6dB to -9dB, so that's why I need to turn up the volume quite a bit on the SRM-252S. I will try your suggestion.
I am using a Topping D50s to feed the SRM-252S, source comes from JRiver on Windows 10 or an Android device with USB Audio Player Pro.

 

[Tugbars]

I think it's subjective. I've read the modded MK2 has more bass than the MK1.

MkI is even more laid back, 2-4khz recession of Mk 2.9 is about 3.5db less than MkI. MkII has right amount of energy in that region to my ears. MkI's metal springs are larger(so your ears get closer to the driver), 1-1.5khz shout of MkI less than MkII's. Oratory1990 measured MkI//and port modded MkII. Check for more details.

SR007mkI

SR007 mkII with port mod,

Credits goes to @o7brother. He gave his 007s and 009S to be measured by Oratory1990.

The difference between MkI and MkII bass comes from MkI's port being closed. You can do the same with MkII using a blu-tac adhesive and that is called port-mod.(google SR007 port mod) This mod makes bass tighter and mid-bass sounds more controlled. It's an absurdly easy mod to do. Port mod gives tighter bass, without it you get more bass but it's bloated and lacks texture. After port mod, I think it's necessary to give +4db low shelf bass boost under 34hz if you are into such stuff.

Probably they changed diaphragm material with MK2.5/2.9, this is my speculation of course, because later models have better treble performance especially if you are using a good dac. Both models are extremely hard to drive and because there's too much energy in treble/air region, you really need a good dac with good precision and sibilance control.SR007 may seem cheaper than other high-end headphones, however when they are not driven properly, they sound worse than 500$ cans.

 

[talan7]

MkI is even more laid back, 2-4khz recession of Mk 2.9 is about 3.5db less than MkI. MkII has right amount of energy in that region to my ears. MkI's metal springs are larger(so your ears get closer to the driver), 1-1.5khz shout of MkI less than MkII's. Oratory1990 measured MkI//and port modded MkII. Check for more details.

SR007mkI


SR007 mkII with port mod,

Credits goes to @o7brother. He gave his 007s and 009S to be measured by Oratory1990.

The difference between MkI and MkII bass comes from MkI's port being closed. You can do the same with MkII using a blu-tac adhesive and that is called port-mod.(google SR007 port mod) This mod makes bass tighter and mid-bass sounds more controlled. It's an absurdly easy mod to do. Port mod gives tighter bass, without it you get more bass but it's bloated and lacks texture. After port mod, I think it's necessary to give +4db low shelf bass boost under 34hz if you are into such stuff.

Probably they changed diaphragm material with MK2.5/2.9, this is my speculation of course, because later models have better treble performance especially if you are using a good dac. Both models are extremely hard to drive and because there's too much energy in treble/air region, you really need a good dac with good precision and sibilance control.SR007 may seem cheaper than other high-end headphones, however when they are not driven properly, they sound worse than 500$ cans.

I have STAX 353x and RME ADI2. Would this be a good match?

 

[Tugbars]

I don't know about RME-ADI2, however I used to use a dac something similar to that: Sabaj D5. It is one of the best measuring dacs right now.

Subjectively speaking: I always thought that Sabaj wasn't actually competent enough in accurately putting out the audio image however to compensate that, it was overprocessing & overpolishing the sound and giving me something shiny yet something which is far from the real image. This can be due to bad reconstruction filters they are using or bad oversampling. I don't really know, It is okay for a 500$ dac I guess. As a result, trebles get really too bright. On top of that, I was able to hear all the detail but the raw resolution was missing because the stereo image being too overprocessed. These are completely my personal impressions, I just wanted to share them just because with oversampling dacs which are kinda affordable and measure extremely good, this seems to be the case, at least for me.

Now I use Denafrips Pontus, the biggest difference is how correct imaging is with Pontus and there's more depth in soundstage than before. Layering & Staging has been improved. I used to EQ down 8-12khz region before, now I don't have to do that anymore.

All I want to say is actually to make sure that you listen to SR007 with your dac first, it's because when powered properly SR007 has a lot of energy in 8khz+. You wouldn't really want your dac to have a bright sounding presentation there.

And as to your amp, unfortunately 353X does not have power(current output) to drive SR007. They can get really loud but they won't sound pleasant. And this won't be because 353X is a bad amp, it's a great amp, it just doesn't have enough power.

 

[gurbina93]

@PointyFox thanks for the info, good to know these headphones can handle it.



Yep, I set it to auto gain and it usually the final gain ends up in -6dB to -9dB, so that's why I need to turn up the volume quite a bit on the SRM-252S. I will try your suggestion.
I am using a Topping D50s to feed the SRM-252S, source comes from JRiver on Windows 10 or an Android device with USB Audio Player Pro.

I decided to unplug everything and move it to move it to my home office... After that the issues disappeared.
Not sure if it was a bad connection or some of interference as the circuit in my bedroom for some reason has an AC unit and a heater drawing power from the same circuit as the power outlets, the AC runs 24/7 and I'm not sure whether that could have caused it. Also I was using the USB port of a Belkin power outlet to feed the Topping D50, didn't bother checking on the output amperage of the port.

I was wondering why I started noticing this issue if the first weeks in which I had my setup I didn't have any of these, then I moved it into my bedroom but didn't use it for a while or only at low volume at night.

Then lately with all the pandemic numbers going up I started working from home and using it more, to battle all the outside noises you can hear during daylight I had to start cranking up the volume and that's when I noticed something was wrong.

 

[Moak]

Come on folks, please be a little more precise when naming and identifying Stax amps (and gear). If you're not sure, then say nothing. Else it gets really confusing for everyone, and especially for any n00bs who are trying to learn about Stax.

These exist:

With two 6CG7/6FQ7 tubes:
SRM-006t (small t, not T)
SRM-006tII (not a Mk.2, not a T2, but 006tII)
SRM-006tS (latest model)
= Mostly the same as the older SRM-T1 (without balanced input), SRM-T1S (with balanced input), and SRM-T1W (with variable bias and pre-amp capabilities).

SRM-600 Limited, with two ECC99 tubes, slightly more power than SRM-006t[II/S].

Which one is the better? The SRM-006tS or the SRM-600 Limited on a L700 ?
...or is there no difference?