Schematic Needed Superex PEP-77C and PEP-79 "step-up and bias box" for PEP-71 Electrostatic HP
Aug 26, 2013 at 2:59 PM Thread Starter Post #1 of 7

audiotom

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Schematic Needed
Superex PEP-77C and PEP-79
"step-up and bias box" for
PEP-71 Electrostatic Headphones.
 
I picked up a set with no energizer and want to check them out.
 
There are several variations of the "Electrostatic Headphone Jack Pinout" Stax, Koss, Stanton, Superex etc.... Has anyone assembled a guide???
 
Thanks,
 
TM
 
Nov 28, 2013 at 2:20 PM Post #3 of 7
I have a working Superex PEP-79E Electrostatic Phone. So I have the manual with full schematics and circuit board layout, pin arrangement etc. Mine comes with a PEP-74 headset. The 79E console is a self powered control box using the audio signal to generate the 150 volts bias voltage. It may be very expensive, if not impossible to find the step up transformers.
 
But it should not be too difficult to modify another brand of bias circuit for the Superex.
 
The PEP-74 is one of the most natural sounding phone in its era. It uses a light weight, on the ear design to make it comfortable to wear over longer period of time. Once you try this Superex, it will be impossible to go back to those bulky Koss phone of those days. The price of an over the ear phone is moderate sound insolutation of 30 dB.
 
I am new to this forum and have yet to find my way around in PM or posting the manual file for you. I hope to be able to help you soon.
 
Nov 28, 2013 at 2:42 PM Post #4 of 7
Hi Keilau, once you figure it out I'd also love a copy of the manual. The PEP-74 is a good sounding headphone, but so is the ESP6 with O2 pads after I removed the internal PCBs and recabled for Stax.
 
Dec 1, 2013 at 9:48 AM Post #6 of 7
  Hi Keilau! Thank you for your message. If it is possible, please, send me the files to mail 3348735@gmail.com. Waiting for your reply!

Motorola,
 
I sent the manual to you to the gmail address yesterday and hope that this manual will be of some use to you. I have had some hand written notes on it, but they are easy to recognize.
 
Please, let me know what your plan to build a home grown control console may be.
 
You can see that the original box used some low quality parts. I have made some minor mod to the box. I also wanted to build a separate bias power supply using nixie tube supply. I got the parts but never get around implementing it.
 
Good luck with your adventure. I wonder if AudioTom makes any progress with his phone.
 
Kei Lau
 

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