[NamelessPFG]

What I want to know is why more electret headphone drivers didn't opt for the "back-electret" approach, which basically reverses the usual signal to the drivers by applying the permanently-bias-charged electret material to the stators and the signal to the diaphragm, thus negating the need to weigh down the diaphragm itself with permanently-charged coating.
 
There's a particular set of electrets with Toshiba and Rotel branding out there which took that approach, and at least one poster said it was very competitive with the Stax SR-X/Mk3-an externally-biased electrostatic design!
 
However, this approach to electrets apparently has had common use after all...in condenser microphones. For that matter, microphones opting for the electrostatic principle over the dynamic driver principle is the norm these days, yet it's the opposite for output transducers like speakers and headphones...
 
In other news, that Lambda was delivered today. It's actually in surprisingly good condition given the age, much better than the set I was using to this point. Actually had to scrutinize it for flaws in the housing to see how used it was! No signs of imbalance, either. I feel confident letting Mad Lust Envy review this set as a reference, and I also feel confident keeping this set and selling off the Lambda I started with to recoup the cost.
 
The SRD-6 also works fine; I just don't have much reason to keep it when I've also got the SRD-7/SB.
 
Unfortunately, I'm still waiting on that SRM-T1...no signs of shipment confirmation yet, and I can only hope the seller's taking his sweet time packing it up very nicely.

 

[autoteleology]

Mad Lust Envy wants to review your Lambda? He said he wasn't interested in hearing mine, and I was willing to send him my entire setup; amp, earspeakers, and DAC in all while in New Orleans.

 

[miceblue]

^ yeah I remember him saying something like that...maybe he hates you. >.>

 

[NamelessPFG]

I can't say that he does actually want to review it with certainty, but it's an offer I'm willing to make if he's interested.
 
I had no idea anyone else had made such offers in the past; I just figured that if he was willing to accept my SU-DH1 and Recon3D USB for review, maybe he'd be willing to try out more exotic headphone systems I can get my hands on.

 

[davidsh]

Nobody had any good arguments regarding the O2 being a bad amp? Just wondering if it does measure bad in some ways, or its not so good sound is to be found outside of measurement's scope?

 

[reiserFS]

I finally got my hands on a small stax rig for my desktop, SR-Lambda Pro and SRM-212, in near perfect condition. Can't wait for them to arrive.

 

[spritzer]

Quote:

 
I understand your question.I would guess the answer would be: does an Electret driver panel have to be any heavier than an Electrostatic driver panel? Is one heavier because the electret needs additional treatment or coating to hold the permanent charge?

 
This is just the tip of a much larger issue but it has to do with driver behavior, lack of consistency for stereo sets and reliability issues.  Back electret has the same problems as electrostatics run single ended with the stators fed by two separate bias supplies. 

 

[miceblue]

Quote:

Nobody had any good arguments regarding the O2 being a bad amp? Just wondering if it does measure bad in some ways, or its not so good sound is to be found outside of measurement's scope?

The argument is there is no argument. The saying here is that the O2 is a terrible amp period. Craptastic measurements with crap design with a crappy people following objective crap.
 
That being said, the O2 is my reference amp for dynamic headphones. I like it more than other amps I've tried. I really like it with the HD650. I should compare the mids of the HD650 + crap 2 to that of the SRS-2170 during the next meet since they seem to have a similar treble for my liking.

 

[vid]

Quote:

 
This is just the tip of a much larger issue but it has to do with driver behavior

 
What are some of the outstanding features of electret driver behavior?

 

[Chris J]

​

Nobody had any good arguments regarding the O2 being a bad amp? Just wondering if it does measure bad in some ways, or its not so good sound is to be found outside of measurement's scope?

It's a fool's argument.
It's a $150 amp.
I would not expect perfection from a $150 amp.
But I'm not surprised that a lot of folks think it sounds quite good. They only paid $150 for it and it sounds better than the headphone jack on their notebook computer!

 

[DefQon]

The O2 is a $50 amp. $120 - 150 is what JDSLab's charge for a finished product for those too lazy to build the kit version.

 

[NamelessPFG]

Comparing my two Lambdas for several more hours, it seems like the stock set has a bit more balance throughout the spectrum, with more punch and sparkle, without losing that mid-centricness I love. It also seems a bit more sensitive than the set with rebuilt drivers, with less volume adjustment necessary to get to the same perceived volume.
 
Needless to say, it's a keeper. spacemanspliff's old Lambda with its rebuilt drivers has served me well, but now it's time to pass it on. Curiosity can be harsh on my wallet, but in this case? Worth it, if I can recoup my costs.
 
Meanwhile, I finally have a tracking number on the SRM-T1, but no idea when it'll arrive yet.

 

[DefQon]

You have 2 normal bias Lambdas?

 

[NamelessPFG]

Quote:

You have 2 normal bias Lambdas?

 
Sort of.
 
The first one was bought over 2 years ago, back when I was just getting into this Head-Fi thing with only an AD700 to my name at the time. It was made clear that it had rebuilt drivers with 2.5 micron diaphragms, no mineral wool, and was generally not in stock condition...but that it still sounded good, and for $250 with an SRD-7/SB included, how could I say no? I already had a spare A/V receiver lying around to power the transformer box, so the amp barrier was not an issue.
 
Of course, I couldn't truly say I had an original, Normal-bias SR-Lambda knowing all the changes it underwent. The frame has seen better days, given how roughed-up it looks. The headband, while not obvious to me at the time 'til I got my hands on other Lambdas, is rather stretched-out, isn't as wide, and almost looks as if it was meant for a different arc assembly. The cable actually had a 5-pin Pro bias plug, though there's no way I'd dare risk killing the drivers by plugging it into a Pro bias outlet. (Given that the nameplates at the top of the cups are blank and don't have "PROFESSIONAL" or other text on them, I'm guessing that the original 6-pin cable was damaged somehow, and whoever repaired these things had to use a 5-pin replacement due to the relative lack of 6-pin Lambda cables.) And the pads...they were in such a terrible state that the prior owner actually cut strips of soft microfiber cloth and taped them to the contact areas of the earpads, just for comfort's sake!
 
That's why I went and bought that second SR-Lambda. I wanted to know just how different my set was from one that was still in stock condition...and now I know. The difference isn't extremely drastic and the overall sound is similar once you take the different FR curves into account, but all the little things add up to the point where I'd say "Yeah, it was worth it." Even if I was unknowingly being driven up an extra $100 by another eagle-eyed Head-Fier (who has now managed to acquire a Lambda Pro; hopefully that works out).
 
Maybe someone out there won't mind buying the beater Lambda and SRD-7/SB as their entry-level Stax setup, just as I did two years ago. I still like it better than the SR-202, at any rate...for that matter, it was my all-time favorite headphone until I got the other SR-Lambda, beating out HE-400s and just about every other headphone I had auditioned. I wouldn't hesitate to mention it to anyone looking for a great competitive gaming headphone that also makes a good all-rounder for music, just as I have been doing over the past two years.

 

[davidsh]

You should've tried messing with damping, mineral wool, etc over the years if you haven't already.