Stax SR-007Mk2/SR-007A port mod

[spritzer]

Since this post would get lost in the ever growing Stax thread I'll post it here. If you damage your expensive phones doing this it's your own fault so don't come running to me. Be very careful with any tools this close to the drivers as one slip can destroy them. You have been warned!!!

All you need to do this mod is some blutack, a screwdriver and the patience of a saint to get the damn pads on again. First job if to remove the earpads by simply pulling onto the top edge and they come off. Also remove the spring underneath as it will only be in the way. Simply pull it out of the rubber grommet. Now there is a black plate with 4 screws holding it to the phones together. Just above the cable entry is a small notch cut into the plastic surrounding the driver and that's the port that needs to be plugged. I'm sure that stuffing blutack here will seal it but since I haven't tested it I will only suggest it as a theory. Remove the 4 screws in the black plate and the earpieces are free from the arc assembly (be careful not to drop them!!) and it looks like this.

The port is the cut out above the cable assembly and vents through it. Fill it up with blutack so that is looks something like this:

Assemble the phones and your Mk2/A now sounds like it should have in the first place.

Edited July 14, 2008 by n_maher
updated by request

[deepak]

All hail the glorious Stax fart!

[guzziguy]

All hail the glorious Stax fart!

You shouldn't call Spritzer that!

[spritzer]

You shouldn't call Spritzer that!

[catscratch]

Thanks, exactly what I was looking for.

[Elephas]

I'm scared of removing the earpads and I can't take apart the SR-007 Mk2 because I don't have thumbs.

It's OK, it seems this mod is to make the O2Mk2 sound more like the O2Mk1, and I don't understand why one would want to do that.

[luvdunhill]

I'm scared of removing the earpads and I can't take apart the SR-007 Mk2 because I don't have thumbs.

It's OK, it seems this mod is to make the O2Mk2 sound more like the O2Mk1, and I don't understand why one would want to do that.

can't you use use your trunk? Elephants seem very dexterous with their trunks....

[spritzer]

I'm scared of removing the earpads and I can't take apart the SR-007 Mk2 because I don't have thumbs.

It's OK, it seems this mod is to make the O2Mk2 sound more like the O2Mk1, and I don't understand why one would want to do that.

Get a new amp and report back... ...

[Elephas]

I'm trying, I'm trying, but Justin and Mikhail ignore me. :'(

Maybe I can send the headphones to someone and they'll swap earpads and plug the ports for me. Hopefully they'll send them back.

I don't even have any blutack. The last time I hung up posters in my room was over two decades ago.

[Elephas]

I just realized something (thinking speed slooows down the longer it has been since you've hung up posters).

There's the Markl Mod for the Denon D5000 that makes it sound better than an R10.

Is this the spritzer mod for the SR-007Mk2 that makes it fart?

[Dusty Chalk]

All hail the glorious Stax fart!

Hey, I have a question -- does the 4070 have the fart/squeak?

[Elephas]

Dude, it's a fart, what is this squeak stuff? Is there a rat around? I'm scared of rats.

No, the 4070 doesn't fart much.

However, after it gets the "spritzer mod," maybe...

[Dusty Chalk]

Dude, it's a fart, what is this squeak stuff? Is there a rat around? I'm scared of rats.

Well, maybe I'm thinking of something else...the sound I heard was pretty high-pitched for a fart.

[spritzer]

I just realized something (thinking speed slooows down the longer it has been since you've hung up posters).

There's the Markl Mod for the Denon D5000 that makes it sound better than an R10.

Is this the spritzer mod for the SR-007Mk2 that makes it fart?

I think that the D5000 mod only sounds like the R10 in markl's own idiotic mind. The fact that he thinks Rudi's amps are good speaks volumes...

Hey, I have a question -- does the 4070 have the fart/squeak?

You can force them to squeal like every other ESP but it's not normal.

Well, maybe I'm thinking of something else...the sound I heard was pretty high-pitched for a fart.

The fart is a pretty silly name for it...

[Smeggy]

In the 003 it doesn't so much fart or squeak, more of a cellophane crinkling noise. I made the mistake of putting the 003s on the other night and then decided to eat a small snack... scrinkle-cruncle-scrunch-crankle.

Eating and 003 not a good combo for careful listening.

[spritzer]

In the 003 it doesn't so much fart or squeak, more of a cellophane crinkling noise. I made the mistake of putting the 003s on the other night and then decided to eat a small snack... scrinkle-cruncle-scrunch-crankle.

Eating and 003 not a good combo for careful listening.

This is why I only use them to test sick amps or some other crazy ideas I have.

[spritzer]

Since the pictures are gone now I uploaded them to a more permanent location.

Before:

After:

[slwiser]

Dude, it's a fart, what is this squeak stuff? Is there a rat around? I'm scared of rats.

No, the 4070 doesn't fart much.

However, after it gets the "spritzer mod," maybe...

Does this sound continue like a roar or a buzz? Or is it simply a quick sound like a crack? I have heard noses with my SR-001 and SR-003 both and don't know if this sound is a fault or a "fart". Thanks

[spritzer]

Does this sound continue like a roar or a buzz? Or is it simply a quick sound like a crack? I have heard noses with my SR-001 and SR-003 both and don't know if this sound is a fault or a "fart". Thanks

A buzz sound is usually due to some debris in the drivers shorting it out but the fart is more like a squeal generated by the diaphragms when air is pushed through them. That being said the baby Stax is very noisy due to the design.

[slwiser]

A buzz sound is usually due to some debris in the drivers shorting it out but the fart is more like a squeal generated by the diaphragms when air is pushed through them. That being said the baby Stax is very noisy due to the design.

Is there an easy method of cleaning out that debris?

[spritzer]

Is there an easy method of cleaning out that debris?

The short answer is no as it is so small you can't see it. It also requires a total disassembly of the drivers to get to the diaphragm which can be tricky or just impossible.

[spritzer]

Time for an update. I finally got depressed enough to rip open my two SR-007's to figure out what was what. I took some pictures but they will have to wait until later tonight or tomorrow.

First off, the drivers in the Mk1 and Mk2/A are identical from the outside and probably are the same. I had never compared them side by side until tonight and it's clear that the only difference is the lack of a small cover over the cable entry on the A/Mk2 due to a different design. I do find it odd that Stax didn't employ said cover on the SR-Omega/007 hybrid as they just left the cable entry wide open...

Comparing the rest of the parts then they are all identical between the phones, same chassis, arc assembly and the black base plates for the drivers are also identical. The A/Mk2 still has the mounting holes for the small cable entry cover of the Mk1. The only real difference is in the metal spring which holds the earpads in place and gives them the ability to rotate. At first glance they look quite similar but side by side it's clear that the A/Mk2 unit has a slightly different bend in the center and it is quite a bit smaller. The Mk1 unit is 100.20mm in circumference but the new one is only 92.90mm which means that the pads aren't held as firmly and coupled with the increased bend at the center pin allows the pads to lift more.

How much of an effect this has is still unknown but I swapped the springs between the Mk1 and A/Mk2 and I'll report back when I've had some time to do so. First impressions of the A/Mk2 with the Mk1 springs and the ports blocked are favorable but lets see what a few hours will tell me.

[spritzer]

Here are the two phones side by side, Mk1 on the left and the A on the right. This matte white is very hard to photograph with my crappy Canon but study it closely and they are identical.

Here is the Mk1 driver with the small cover which goes over the cable entry. Better then blutack that's for sure...

Here are the two springs side by side, Mk1 on the left and A/Mk2 on the right. Not the difference and how hard it will be to make the A/Mk2 unit bigger...

A bad picture showing the same thing as before.

Here you can see how different the angle is, with the A/Mk2 units having a noticeably wider angle and thus capable of lifting the pads higher away from the drivers.

[dvse]

It's quite clear why Stax has changed the cable design - if you look at the original, the cable strain relief is not completely fixed in place - small movements over the years will very likely cause the tiny leads (or solder joints) between the cable and the driver to fail from fatigue.

The new design eliminates this problem - now the driver and the strain relief are effectively one unit.

But you are indeed correct - the drivers appear identical - the only change is likely to be in the aluminium cup to hold the new strain relief screws?

I think it's looking quite plausible that after all this could just be variation between samples due to poor quality control?

[spritzer]

The Mk1 cable entry is fixed in place by the small cover as it is secured by 2 screws into the black mounting plate. Far from perfect though but I've been talking to a few Stax dealers and the issue was with the very stiff cable entry. It doesn't flex at all so if the cable is pulled then it will break eventually.

I thought I had some pictures of the inside of the A/mk2 cable entry but I can't find them. They are pretty similar though but Stax may have added two tapered holes to fix the screws. I'll have to check when I swap out the earpads.

All of this could be due to poor QC or teething problems with the new design but since others have reported similar audible artifacts I would have to conclude that this was a byproduct of the new design. With the Mk1 springs in place the sound is indeed different, less forward in the midrange and I doesn't bug me like stock unit. That being said they more forward over all then the Mk1 with cymbals and voices closer in the headstage but it isn't annoying... not yet at least. Next step is to mount Mk1 earpads with the Mk1 springs and see what happens.