A S.E.X. for Stax. Putting the E back in sEx :)
- Thread starter johnsonad
- Start date
johnsonad
New member
Alright, back on topic and talking about my S.E.X. project 
Tonight I installed a couple of switches and the OPT's that came with the kit and for some unknown reason it worked right away. I'm now able to use my S.E.X. kit with both my speakers and the Stax headphones saving quite a bit of change and with the flip of two switches I can move between the two.
This is the first time hearing the S.E.X. with my speakers and it does sound good! I'm using a 1.1uF PF cap and the OPT wired for 8 Ohms. They seem to have lost lower mid bass and bass though (less bass and more of an upper mid emphasis) and I'm wondering if I should very the PF cap size or try a different impedance on the OPT's? Any suggestions from the head shed here? Maybe the transformers need to break in some??? I'll mic the two amps this weekend and post the curves. It may be that the lower mid bass and bass need a bump is all. As of now the highs are a little painful with my horns.
There is very little hum with my 100dB speakers and I must place my ears next to the drivers to hear anything. The soundstage is deep and the room sounds realistic. I'm using some Ruskies to start off with to included a 0.13uF SSG silver mica and a few paralleled K40's for the PF.
Tonight I installed a couple of switches and the OPT's that came with the kit and for some unknown reason it worked right away. I'm now able to use my S.E.X. kit with both my speakers and the Stax headphones saving quite a bit of change and with the flip of two switches I can move between the two.
This is the first time hearing the S.E.X. with my speakers and it does sound good! I'm using a 1.1uF PF cap and the OPT wired for 8 Ohms. They seem to have lost lower mid bass and bass though (less bass and more of an upper mid emphasis) and I'm wondering if I should very the PF cap size or try a different impedance on the OPT's? Any suggestions from the head shed here? Maybe the transformers need to break in some??? I'll mic the two amps this weekend and post the curves. It may be that the lower mid bass and bass need a bump is all. As of now the highs are a little painful with my horns.
There is very little hum with my 100dB speakers and I must place my ears next to the drivers to hear anything. The soundstage is deep and the room sounds realistic. I'm using some Ruskies to start off with to included a 0.13uF SSG silver mica and a few paralleled K40's for the PF.
Paul Joppa
Moderator
Yes the transformers will need ~50 hours of music to break in. Like caps and speakers (though probably for different reasons) the bass needs time to wake up, and the treble needs time to get rid of the edginess. Just my experience, YMMV, etc. :^)
If I only had STAX and my Orcas I'd be more interested in modding my SEX to drive just those, but I don't see myself getting rid of my K240DF or K400 anytime soon. I would be most interested in a dedicated STAX amp which would probably yield the best results. Are there many other STAX owners on this forum?
Doc B. said:
I forgot to install a power switch, and when it wouldn't shut up, I put it in the wife's trunk and forgot about it!
johnsonad
New member
tdogzthmn said:
If you already use your SEX amp for those listed cans, you could use it for all three (standard cans, Stax and speakers). Dedicated Stax amps are an expensive undertaking and the so called "good" ones run several thousands of dollars. As I've posted before, I wasn't impressed by any of the current Stax offerings. Take a look at the Stax amp thread on Head-Fi for YEARS worth of conversation on the topic.
I have posted on Head-Case even though I'm not a headphone practitioner. They seemed mostly nice. I think I was chiming in on the Schiit stuff. Anyway, interesting how you find different folks out there. I think the forums that tend to have older members are a bit more casual and friendly.
johnsonad
New member
It will. I did the same thing with the SEX but with half the iron (no step down to step up).
Btw, the SEX is sounding better than ever with my speakers. I'm working on adding a second base now to adjust for the extra transformers under the hood and have been playing around with capacitors. I'll post a pick later this week once finished.
Btw, the SEX is sounding better than ever with my speakers. I'm working on adding a second base now to adjust for the extra transformers under the hood and have been playing around with capacitors. I'll post a pick later this week once finished.
I have the impedance switches also installed on my SEX so I can alter the amp's output if needed or try the Balanced setting to see if it will have an impact. Glad to hear your SRD-7 plus SEX combo was usable. Do the modifications you made to your SEX work better than using the SRD-7 with the stock amp? Hopefully you can snap your pics of the completed amp once you've got it in "final" form.
johnsonad
New member
I've been busy with the SEX. The second wood base was finished and glued to the original base. It's pretty tall now but doesn't look bad. I put in two paralled 1uF KBG-MN (2uF) for the PF and I'm breaking in a pair of Mundorf S/G/O for the coupling caps. The caps are on twisted wire extensions and attached to the lower base.
While the SEX is burning in I swapped back to my Quad 303 for speaker use and was very impressed by the sound. Neither amp is perfect and both offer subtle differences. To be honest, the differences are so little that I'm wondering if I got lucky and have a SS amp that has a sound signature of a SET or if I'm at a point of diminishing returns and that my system isn't able to reflect the changes at this point. It could also be that I'm changing for change sake and just need to relax for a while. Both amps sound wonderful and I'm very happy with the system as a whole.
While the SEX is burning in I swapped back to my Quad 303 for speaker use and was very impressed by the sound. Neither amp is perfect and both offer subtle differences. To be honest, the differences are so little that I'm wondering if I got lucky and have a SS amp that has a sound signature of a SET or if I'm at a point of diminishing returns and that my system isn't able to reflect the changes at this point. It could also be that I'm changing for change sake and just need to relax for a while. Both amps sound wonderful and I'm very happy with the system as a whole.
