[padam]

Yes, difficult to tell if there is a jumper inside or not, but on the older amps soldering is definitely easier than on the newest ones (but I think that even the newer ones are not that challenging either).

 

[DefQon]

Sometimes they are on the bottom as well, pop off the bottom panel and then you're able to tell. Most evidently on some of the SRM1 MK2/Pro units I've had.
 
The newer Stax amps (i.e. 323S and above) from Japan usually have two wires cut off from the transformer taps to the jump board, you have to re-solder a new wire from the multi-tap on the primary to the jumper board and then re-solder the jumpers to your preferred AC voltage.

 

[mangler]

Hey guys, I may have an opportunity to grab a pair of sr-007mk2.5 for ~$1000. The catch is that there is a channel imbalance, where the left side is ~ 25% louder, but I can adjust for this on my DAC. So, in your opinion, what's the dumber decision: 1) knowingly buy unbalanced headphones, or 2) miss the chance to get some O2s for $1000?

Right now I think I'll probably buy them, especially since I could never afford them new and getting them used would be still be a bit of a struggle. Still, I'm curious to hear what you stax masters think.

I should probably mention that I've actually been using them for about a week and quite enjoy them even though I know (and can hear) they don't have all the juice they crave.

 

[negura]

It may be more than just an imbalance in dBs. 1000 is a lot for defective headphones.... Another option is to find how much changing a driver costs.

 

[dukeskd]

Once there is imbalance, it can only get worse..

 

[paradoxper]

  So today I was a very good day indeed. I got to finally hear the mighty T-2. And it was just as I expected --> SPECTACULAR. Very impressive build by GeorgeP (also the builder of my KGSSHV). Truly endgame territory and on his PWD2, the sounds I heard from my newly purchased SR-007 MK1s was simply breath taking!
 
 

Is George up for commissioned builds? I know of one dude who is having one built, which is running him $10k+, just curious if we'll ever have somebody down to do builds.

 

[MacedonianHero]

  Is George up for commissioned builds? I know of one dude who is having one built, which is running him $10k+, just curious if we'll ever have somebody down to do builds.

George has a very good day job. You might want to ask him though. 

 

[mangler]

It may be more than just an imbalance in dBs. 1000 is a lot for defective headphones.... Another option is to find how much changing a driver costs.

I asked Yama, and they quoted me $1600, which is NOT going to happen.
I guess I was thinking I could live with rebalancing everything using my DAC, but if this is a sign that things are only going to get worse ill certainly pass on these.
For some reason I was also under the impression that channel imbalances aren't terribly uncommon in electrostats, and that maybe this shouldn't be a deal breaker if the price is right. From your responses it sounds like that's not the case, and I don't want to dump a bunch of cash into something that is headed towards failure, so maybe I'll try to be smart and skip these

Thanks for your responses too...you probably saved me from doing something hastily and stupid. Too bad though, because I really like these, but maybe I'll use this opportunity to try out some lambdas (this was my first stax experience, and I think I'm falling for the stat presentation )

 

[3X0]

  Once there is imbalance, it can only get worse..

 
Not true. Some imbalance is temporary.
 
 
 
I'd wait for spritzer to chime in.

 

[dukeskd]

   
Not true. Some imbalance is temporary.
 
 
 
I'd wait for spritzer to chime in.

It is worth mentioning the recent SR-009s imbalance debacles (imbalances that were solved simply by shipping on an airplane) and parasitic charge. In the case of parasitic charges, a few weeks/days of not using the headphone will solve imbalance once charge is gone. Humidity is also another factor that could damage drivers, however putting the phones in ziploc bag for a number of weeks could correct the problem.
 
Spending $1000 on a headphone that has confirmed channel imbalance is not a wise investment as it could be permanent.

 

[DefQon]

From my experience with the pairs of Lambdas that I've owned that suffered imbalance issues, most of them got worse to the point where it would distort on the low end spectrum of sound, any bass will cause distortion. Yamas is also a rip off and unreliable with zilch communication.

Considering used MK1's do pop up from time to time for $1.6-1.8k I'd rather that option then buying an imbalanced MK2.5 that could get worse and eventually you lose some $ when you sell it off. Your best luck is either check there is no debris in the driver by opening them up or looking for a puncture in the dust filter or you can leave them playing for 4 months straight continuously, that is how long it took one of the imbalanced normal bias Lambdas to fix itself and the only one that did fix itself.

 

[dukeskd]

From my experience with the pairs of Lambdas that I've owned that suffered imbalance issues, most of them got worse to the point where it would distort on the low end spectrum of sound, any bass will cause distortion. Yamas is also a rip off and unreliable with zilch communication

The issues you had with the Lambdas sound like the Mylar diaphragm was faulty and that is definitely not solvable. Yamas would only charge you an arm and a leg to replace them drivers.

 

[DefQon]

I don't know if it was the mylar tension loosening or the parasitic charge but one of them was a brand new 407 out of the box 2 weeks straight into it bam imbalance, returned them got a replacement and sold it off.

 

[3X0]

  The issues you had with the Lambdas sound like the Mylar diaphragm was faulty and that is definitely not solvable. Yamas would only charge you an arm and a leg to replace them drivers.

I believe some SR-009s also reported distortion in the bass, and were returned without distortion/imbalance with the same serial number.

 

[DefQon]

I believe some SR-009s also reported distortion in the bass, and were returned without distortion/imbalance with the same serial number.

Indeed this is also what I've also read from that thread also and it almost sounds like a solution to throw your Stax at the wall should it suffer imbalance problems.