Superex Headphone Thread

[mypasswordis]

Greetings, fellow AKers! I recently purchased a lot of interesting Superex electrostatic headphones, and thought I'd share some pics first and impressions on sound later. There are other Superex headphones of interest out there, so I thought I'd just make an all-encompassing Superex thread. Feel free to post anything Superex related in this thread, including any of the company's history here. I did not purchase from the same seller what I believe to be the first Superex electrostatic headphone, the PEP-71, which I'm now starting to feel was a mistake due to collecting purposes even though I'm pretty sure the sound is lackluster. Anyway, here are the spoils:

PEP-74

PEP-81

EP-5

The PEP-74 and PEP-81 are full electrostatics, while the EP-5 is a dynamic/electret hybrid.

After initially plugging the PEP-74 in, the sound was quiet and distorted, so I opened it up and cleaned out the deteriorated foam. I have found this is really a necessary procedure from anyone headphone from this era, so I will have to open up the other two and clean out the foam gunk even though they seem to be producing fine sound. Here are some pics I took of the process in the PEP-74:

Big thanks to spritzer, wualta, and facelvega for making me aware of Superex electrostatic headphones in the first place, and wualta for sharing his seemingly infinite knowledge of acoustic principles and orthodynamic and electrostatic history.

 

[wualta]

...and wualta for sharing his seemingly infinite...

HA! If only! But this is a fascinating look at the Superex 'stats I never owned. My PEP-71 (used in the PEP-79 system) with its big hollow untreated plastic cups certainly lacked bass and had a bright top end, but that was okay because back then nothing else had much of a top end. Nothing remotely affordable, anyway, but things were changing very quickly as the industry gathered steam.

I was always curious about the 74 depicted above. Had Superex learned the lesson of the Sennheiser 414? Only mypasswordis knows for sure, now that's he's done the dirty work and got the 74 working again.

So-- the obvious question: How does it sound?
.

 

[mypasswordis]

The PEP-81 sounds fairly balanced in frequency response, gently rolling off in amplitude at both extremes. Its limits are shown in busy and loud passages where it loses steam, but I think that's largely because of the poor way the drivers are mounted to the chassis (foam and cardboard sandwich, with those four metal hooks). I will have to look into how spritzer modded his PEP-74. After taking a brief look inside, there's no reason for me to believe the PEP-81 is anything but a closed version of the PEP-74 but I could be wrong, perhaps the drivers were updated.

The EP-5 is more tilted to the bass and a bit tubby sounding. The dynamic driver is more efficient than than the electret which keeps the treble somewhat subdued, though still noticeably electrostatic. If I push the headphones into my head (thereby squishing the thick pads) with my hands the bass amplitude increases to ridiculous levels. I think there should be a bit more thickness in the pads to balance out the frequency response and decrease tubbiness, or maybe there are other ways to do so. Here's a pic of the inside of the EP-5:

I have to get back to you on the sound of the PEP-74 after I find a better way to fix the drivers to the baffle/chassis, but from what I remember of my other PEP-74 it actually sounds pretty similar to the PEP-81, or what it would sound like as a vented-open headphone.

 

[ths71]

Never heard their electrostatics but my first set of cans were Pro B VI. Used and abused them for 20 years and finally wore them out. They were great sounding headphones.