The Headcase Stax thread

[padam]

Count me in, but I need to sell this and that first ("this" is almost done:))

[Dusty Chalk]

FYI - I was able to pick up the 2nd 404LE locally. I think DC was interested in them first, let me know. If not, then Fierce Freak. otherwise, anyone else? or I'll keep as backup pair.

Uh...uh...yeah, sorry, I edited my post like 5 minutes after I posted and backed out...if you don't get any takers, I don't want you to be stuck with them, I'll try to work something out with you, but if someone else wants them, go ahead...

[JimP]

no problem, DC. FF, I'll respond to your PM, then to Padam.

[JimP]

OK Padam, you're up! Please PM me if you want these..

[Voltron]

OK Padam, you're up! Please PM me if you want these..

If you get stuck with a pair and want to sell, let me know. Not actively looking, but they are Limited, after all.

The SR-Omega sound so sweet even out of the 007t. I am truly looking forward to owning one or two better amps so I can spend time with these at their best.

[JimP]

Apologies, I've decided to just hold onto the 2nd pair for now. my SRD7Pro energizer just came in, and my SRM-600 should arrive from Japan tomorrow, so I'll just disappear for a bit to listen to these.

[mypasswordis]

If keeping the original looks are not important, I would just get the Gamma Pro cable from eBay as it is better than the SR-X cable.

I swear I bought a "5 pin" cable from the dude but he ended up sending me a second normal bias Lambda cable. Edit: Nevermind, I'm an idiot and actually just bought two normal bias Lambda cables. Stupidity is one of my best virtues. Anyone want to buy the second one off me or trade for a 5 pin? Maybe Colin wants to trade for some drivers?

[Beefy]

Quick question...... what is soldered 'across' the stators of a Lambda normal bias at the cable connection? Is it anything that could go bad over time?

[spritzer]

It's overload protection (diodes) also found on other low bias phones.

[Beefy]

Alright, I'll duplicate the post I made in the Exstata thread on Head-Fi to give a bit more context to why I am asking the above question......

Some of you may remember that I was having a 'crackling' issue in one of the drivers of my normal bias Lambda? Well as of today, the story gets really weird......

I bought a whole heap of parts to refurbish these phones, which I have been doing over the last couple of days. Hooked them back up to my Exstata after the recable today and they were unlistenable, with loud and intermittent buzzing and crackling. Now I've done lots of troubleshooting for this issue. Only one of the drivers is having problems. It isn't specific to one amp channel, because the problem goes with the affected driver when I switch the channel that the bad driver is hooked up to. Still there when a source isn't connected. Still there when I disconnect the power supply to luvdunhill's digital volume control. Doesn't seem to be present on my T-amp SRD7-SB combo, but I need to do more tests to confirm this tonight.

But just by chance I touched one of the Q11 heatsinks, and the buzzing suddenly stopped. Removed my fingers, it started again. I could hold my fingers on there for about a minute, before it started to progressively have no effect and the buzzing started again. And yes, before anybody asks, the heatsinks are properly grounded as per the Exstata website.

So wtf could possibly be going on? The amp seems to be going into some sort of oscillation, but only on the channel that this one particular driver is connected to. I wonder if whatever component is connected 'across' the stators at the cable connection is going bad? Could there be an intermittent short inside the driver? I've gone through this very logically, but it is confusing the crap out of me and I really don't want to effectively throw away the $1000+++ that I have invested in these phones and amp, so any and all suggestions are welcome......

[EDIT] Ah, just missed the diode post. Don't know if it makes my problem any clearer or not?

[spritzer]

Odd indeed. Strange behaviour like this can present it self when you have a driver which has arced quite badly so there is some carbon left on the diaphragm. This will shorten the D/S gap and cause the oscillation and other weird stuff to happen of the bias is raised a bit. Most of the SRD units are running a bit below spec (since most of them were made in a time when the NB spec was 200V and not 230V) plus the load resistors are generally smaller. Now assuming you set the bias with a meter that didn't overload the bias supply causing it to sag and thus give out more voltage in real life this shouldn't be an issue but it has been known to happen.

As for the diodes, they shouldn't fail but you can safely remove them to see if it is the problem. I always did when working on NB phones since most of us know the dangers of overloading the drivers.

[Beefy]

Thanks mate, some options to try

Regarding the bias setting and measurement, it is set at 230V with a VC99 which does not seem to sag, even after several seconds; I will try with the bias lower and see if that helps. In addition to carbon deposits or bad diodes, I suppose something might also be shorting through the mineral wool at the back? I will do some testing with the back case removed, but I would have thought the dielectric strength and resistivity of that stuff would be very high.

I would blame the amp, but the problem seems to only show up with this 'bad' driver. It all just makes no damn sense......

[spritzer]

The voltage sags in a split second and then stays at that value so try turning off the auto ranging on the VC99 and see what is the first number you see, that would be closest to the true value. Also the VC99 isn't as accurate as a Fluke 179 so I'd try decreasing the bias down to 200V or so.

The mineral wool is basically glass and that doesn't conduct with these voltages.

[Hopstretch]

Can I just say how happy I am to have my O2s on my head again after a two-week break? Biblically happy.

I am the Alpha and the Omega, who is and was and evermore will be -- the ruler of all.

[mypasswordis]

Pfft, for you to use that quote you need to get an Alpha Pro Excellent and a real SR-Omega.

[cetoole]

Can I just say how happy I am to have my O2s on my head again after a two-week break? Biblically happy.

Same here!

[mypasswordis]

Converting this cable to pro bias is making me rage so hard. Again mainly mostly because of my stupidity. At the end of tonight I will either have a working SR-X Pro or a fubar Stax cable.

[Duggeh]

Have you heard or considered the SR-202?

Trying one used will cost you nothing as you'll be able to sell a 2020 or 2050 for what you paid and they're much more desk-space friendly than an O2 rig.

If you're set on the Omega 2 though, then I'd certainly say that you should consider a JH13. Goes well with that Pico.

[deepak]

so, i will be moving into a new office soon (it's a university setting, so soon means any time between tomorrow and June 2037, but probably closer to tomorrow than 2037). this new office is built in such a way that will keep me from being able to hear when people knock on the door. well, it's built in such a way that i'll be able to pretend i can't hear people knock on the door, which amounts to the same thing. this means that i can have a music system. it does, however, have shitty acoustics, so speakers are out. i was thinking about some kind of HD800 style rig, but then i realized that i could get Staxen for the same money. i've only heard really high end Stax systems, that's all i know. i know i want O2s (i don't care which version). i also know don't want to buy a BHSE, or anything near that price range, regardless of how good it sounds (and i know it sounds fucking radicool). what would i have to spend to do something decent? i plan on getting a decent DAC, so i'd want some amp that will do justice to the source. 717? i might just get the HD800 and a Pico (assuming it can drive the 800s well?), or one of the all inclusive headroom systems and skip the DAC entirely, as i do like the HD800s a lot, but i also like the O2s.

It will come down to which one you like more Omega 2 or HD800? You can build very nice systems around both of them.

Personally I would get the Omega 2 with either a KGSS or 717 since I know those combinations sound good then go with whatever source you wanted. The Exstata sounds like a good amp too.

[cetoole]

Why wouldnt nearfield work?

[deepak]

i like both, haven't heard either enough to say which i prefer, unfortunately. maybe i should get the 800s and the appropriate cable and try them at home first, for a while.

Yup Headroom might even have a balanced stock cable version of the HD800.

This is the impedance curve of the HD800 vs HD650, you might need active amplification with the HD800

[Duggeh]

did you post before or after my edit, you Scottish bastard?!!

Before the edit displayed, you colonial bastard.

And the JH13s, really are that good. They really are. I mean, I love the O2s, and I like the HD800 quite a lot, but really. The JH13s are better than both. Just don't tell Birgir.

[mypasswordis]

because i don't care for nearfield that much? loses most of the strengths of speakers, while picking up few benefits, in my opinion.

How about extreme nearfield? A la K1000.

If you are getting a Lambda, I would not recommend the SR-202.

[postjack]

how about using JH13s in a nearfield setup? all the benefits of speakers, with less benefits of speakers because it's nearfield I guess, but you can hear things because you won't have the IEMs in your ears, but you still get that awesome JH13 tonality and shit.

[n3rdling]

Get an O2/717 combo from yahoo japan...they come up often enough and you'll save a couple hundred vs buying on HF.