The Stax thread (New)

[HeadphoneAddict]

Originally Posted by antonyfirst

Ok guys, Ludo fixed this headphone by adjusting one connection inside the right earcup, and now it works. I was so curious to hear the headphone that he is lending it to me for a few days.
The headphone doesn't have any imbalances to my ears, using my amp.
I compared thoroughly the SR-3unknown (as we can't figure what drivers it uses, so for me it's now a SR-3u ) and the SR-003, using a SRM-1 MkII Pro with both its outs (normal bias and pro bias outs).
The two are pretty similar, but the SR-3u are darker than the SR-003. The SR-3u show a wider recession in the upper mids, which attenuates cymbals, sibilance and metallic details more than the SR-003 (which is already recessed at 8kHz). Vocals (especially female vocals) are meatier using the SR-3u, and lack some air compared to the SR-003. Soundstage is pretty similar with both, the SR-3u are more comfortable but, like every SR-3, with hot weather they made me sweat.
Vocals are more forward with the SR-003, due to them being less recessed in the upper mids. Both have some warmth in the lower mids, but with the SR-3u vocals sound farther from the listener (volume wise, not space-wise).
It's hard to evaluate speed differences, but being more revealing in the upper mids, the SR-003 sound more airy and detailed.
I preferred the SR-003 for sound, while the SR-3u are more comfortable and can certainly please people who like bass and are a bargain under 100€. They remind me of the Shure E50, but it has been to long since last time I listened to the Shures. Due to my sound preferences, anyway, I consider the SR-003 more balanced while not neutral in absolute terms (for example compared to the SR-X MkIII Pro).

That is very much what I heard with the SR-3 I bought from Spritzer a while back when compared to my SR-003 (using SRM-1 Mk2 Pro). I agree with you completely.

My SR-5NB are much closer to my SR-003 (with SRM-1 Mk2 Pro), being more airy and sparkly than the SR-3, while I felt the SR-3 were closer to my stock SR-001 Mk2.

[twestby]

Originally Posted by spritzer

The SR-X Mk3 uses SR-5 drivers with a 2um diaphragm. The Mk2 uses a driver based on the SR-3 but I can't remember what diaphragm it used...



Ditto on what Hirsch said but are you talking about the Mk1 or Mk2 SR-007? The newer model is slightly more alive sounding on the lesser amps due to its more forward nature but still needs all the same amount of power to shine.

Spritzer, I'm bored w/ my 3050ii. Do I get the Omega II w/ the 007tii or the 727ii?

TIA,

-Tim

[audiod]

Originally Posted by twestby

Spritzer, I'm bored w/ my 3050ii. Do I get the Omega II w/ the 007tii or the 727ii?

I would look for a used 717. Search this thread for the many many comments on these models driving the O2.

[ericj]

Originally Posted by antonyfirst

Ok guys, Ludo fixed this headphone by adjusting one connection inside the right earcup, and now it works. I was so curious to hear the headphone that he is lending it to me for a few days.
The headphone doesn't have any imbalances to my ears, using my amp.

I've been reluctant to talk about it, because it seems so unfair, but the channel imbalance in the SR-5 I got from Spritzer seems to have disappeared under similar circumstances.

[edstrelow]

Originally Posted by audiod

I would look for a used 717. Search this thread for the many many comments on these models driving the O2.

I see few positive reports about the Stax tube amps, but more support for their transistor offerings. Certainly I am finding my 717 sounds great with the 007A. But these phones are not that bad with lesser amps, such as my SRm3's which only have 300 volt swing.

Still I think power and volt swing are issues and possibly twestby should get the phones first and see how he likes them with his current 323II amp. With a 400 volt swing it is close to the 717's 450 volt swing.

The best Stax tube amp , the 007tII, only gives a 340 volt swing.

[ludoo]

Originally Posted by ericj

I've been reluctant to talk about it, because it seems so unfair, but the channel imbalance in the SR-5 I got from Spritzer seems to have disappeared under similar circumstances.

Damn clockwork phones.

[wsoxfan]

I am seriously thinking about upgrading my Stax outfit.
First I want to see if I can get a reasonable price on my current outfit:
Lambda Pros with SRM-313 amp.
Both the phones and the amp sound great and are in excellent shape.
Anyone interested please PM me or reply.

[spritzer]

Originally Posted by audiod

I would look for a used 717. Search this thread for the many many comments on these models driving the O2.

Ditto. I'm using one now and it will tide me over until I get the BHSE or finish my own BH.

Originally Posted by ericj

I've been reluctant to talk about it, because it seems so unfair, but the channel imbalance in the SR-5 I got from Spritzer seems to have disappeared under similar circumstances.

Bastard... Glad to hear they jumped back to life.

Originally Posted by edstrelow

I see few positive reports about the Stax tube amps, but more support for their transistor offerings. Certainly I am finding my 717 sounds great with the 007A. But these phones are not that bad with lesser amps, such as my SRm3's which only have 300 volt swing.

Still I think power and volt swing are issues and possibly twestby should get the phones first and see how he likes them with his current 323II amp. With a 400 volt swing it is close to the 717's 450 volt swing.

The best Stax tube amp , the 007tII, only gives a 340 volt swing.

Voltage swing is only a part of the equation. You need current when the impedance drops and that's where the 717 comes out on top. Just look at how much power they draw from the wall and where all of it is going. The Stax tube amps were also never designed to drive the kind of load that a SR-007 presents and simply doubling up in the output stage on the 007t isn't going to transform the basic T1 design. Add that to the 6CG7's being fundamentally the wrong tube for the job and we prefer the 717...

[bralk]

Originally Posted by edstrelow

Still I think power and volt swing are issues and possibly twestby should get the phones first and see how he likes them with his current 323II amp. With a 400 volt swing it is close to the 717's 450 volt swing.

The 323 is not half bad with the 007. (thanks spritzer!) At low to medium listening levels it´s hard to tell the difference from the 717.

Originally Posted by edstrelow

I see few positive reports about the Stax tube amps, but more support for their transistor offerings.

When driving the 404 or LNS my SRM-T1S has enough juice with its 300v
swing. And especially the 404 really benefits from a bit of tube softening at the higher frequencies.

cheers

Tom

[twestby]

Thanks to spritzer and all for taking the time - much appreciated. Plan is to try to get by with the 323II whilst searching for a used 717. -Tim

[slwiser]

Originally Posted by bralk

When driving the 404 or LNS my SRM-T1S has enough juice with its 300v
swing. And especially the 404 really benefits from a bit of tube softening at the higher frequencies.

cheers

Tom

Yes, a very good combo.

[Johnny Blue]

Originally Posted by ericj

I've been reluctant to talk about it, because it seems so unfair, but the channel imbalance in the SR-5 I got from Spritzer seems to have disappeared under similar circumstances.

Eric

Can you explain what you did to get rid of the channel imbalance? I've been following this thread religiously over the years, and fear something crucial must have passed me by on this one: I thought that the original attempt at repairing the SR-3's imbalance did NOT work (despite the great pictures posted during the process!).

I've got some SR-X Mk3s with serious imbalance: they deteriorated rapidly after purchase, not helped by my trying them on what I subsequently discovered was a modified SRM-1 Mk2, where the low bias connection had been replaced by a high bias one (now returned to its original condition thanks to help from Spritzer -- see the original Stax thread for details)!

[ericj]

Originally Posted by Johnny Blue

Eric

Can you explain what you did to get rid of the channel imbalance? I've been following this thread religiously over the years, and fear something crucial must have passed me by on this one: I thought that the original attempt at repairing the SR-3's imbalance did NOT work (despite the great pictures posted during the process!).

I've got some SR-X Mk3s with serious imbalance: they deteriorated rapidly after purchase, not helped by my trying them on what I subsequently discovered was a modified SRM-1 Mk2, where the low bias connection had been replaced by a high bias one (now returned to its original condition thanks to help from Spritzer -- see the original Stax thread for details)!

I'm sorry, all i did was fiddle with the lugs where the wires connect. I didn't expect it to make a difference, but apparently it did.

There are surely multiple causes of channel imbalance. Dirty or loose contacts seems to be one of them. Your problem could be something else.

As an aside, since I'm trying to turn a set of transformers from an E./9 into a Stax energizer, I'm trying to mimic the SRD-7 or SRD-7 MkII bias circuits.

Can anyone here confirm or disconfirm that the 1N6295C aka 1.5KE100C currently available from Littlefuse, Fagor, etc, are a reasonable equivalent of the long-discontinued Z1100 part in the MkII schematic? (or in the case of the original schematic, 1N6293C aka 1.5KE82C for Z1082).

Also pondering the possibility of converting an SRD-7 to an SRD-7 MkII for some day when i have a pro-bias earspeaker.

[Johnny Blue]

Originally Posted by ericj

I'm sorry, all i did was fiddle with the lugs where the wires connect. I didn't expect it to make a difference, but apparently it did.

There are surely multiple causes of channel imbalance. Dirty or loose contacts seems to be one of them. Your problem could be something else.

You got lucky! (I'll try this on mine, just in case!)

Originally Posted by ericj

Also pondering the possibility of converting an SRD-7 to an SRD-7 MkII for some day when i have a pro-bias earspeaker.

Aah, Eric! There have been so many false dawns on this idea: search the Stax threads and you'll find there have been loads of people asking for information on how to do this, but so far nothing has actually come of it (at least, not for dimwits like me, who can tell one end of a soldering iron from another, but can only do a task such as this when given very explicit, painting-by-numbers, instructions!).

[ericj]

Originally Posted by Johnny Blue

You got lucky! (I'll try this on mine, just in case!)

Especially considering what i paid for it.

Originally Posted by Johnny Blue

Aah, Eric! There have been so many false dawns on this idea: search the Stax threads and you'll find there have been loads of people asking for information on how to do this, but so far nothing has actually come of it (at least, not for dimwits like me, who can tell one end of a soldering iron from another, but can only do a task such as this when given very explicit, painting-by-numbers, instructions!).

Well, what I'm proposing to do is replace the bias circuit board with a new one, using few or none of the original bias components.

We could describe in simple terms how one might increase the bias voltage on the existing board by air-wiring some diodes and capacitors, but, we won't, because someone will set their house on fire.

One of the major hurdles to building an all-new stax-style bias circuit (rather than some other bias circuit) is that some of the parts used in the original circuit haven't been available for 10 or 20 years. I think i've found equivalents of the TVS part that regulates the voltage at the first stage, which is one hurdle potentially cleared.

The SRD-7 MkII circuit is desirable for three reasons:

1: Unlike most bias circuits, no mains power transformer is needed.

2: We already know that the circuit works properly, given appropriate parts.

3: An SRD-7 with one normal bias socket and one pro bias socket is at least 70% more useful than either the original SRD-7 or the SRD-7 Pro.