ESP-9 news...

The old ESP-9 was always interesting: Closed e-stats + very sturdy build results in a different kind of sound, compared with the typical e-stat.
But the comfort is/was abyssmal.
The pad-rolling wave of modern times has resulted in many pads that can be bought separately, and in the possibility of finding some that could fit these venerable old headphones.
For example I managed to mount a set of Brainwavz pads*, as in attached photo. It involved a good deal of patience to get them on, but in the end they sat well. The comfort is now acceptable! On level with the HD650, if you ask me. ( That is: A tad too much clamp & weight and claustrophobic feeling, but compared to the ear-crushing original thing: Pure bliss).



* "Brainwavz Replacement Angled Memory Foam Earpad - Black - Suitable For Large Over The Ear Headphones" from eBay

P.S:
For people interested in the ESP-9: I once showed (in a post on Changstar) how they easily can be re-wired to work with Stax amps, a bit down on the page, if the link works
http://www.changstar.com/www.changstar.com/index.php/topic,1491.10.html

 

Refurbishing the ESP9 + the E9 Energizer.

First of all: It is impossible to recommend these vintage phones to other than a particular, rare type of enthusiasts.

I have 7 sets and only 1 works flawlessly ,within its given limits! But OTOH one can be lucky and find good specimen at once, who knows.

Several of my energizers have also failed, but it has always been the fragile ”bias transformers” used in early and ”middle age” models. The later the box the better, as a rule. But there are fixes for everything, and one can find solutions also for the old energizers, maybe I will return to that.

The signal transformers themselves and the rest of the energizer components are rock solid and refurbishing is needed only when it comes to contact points and switches. Oh yes and I would not trust the electrolytic capacitor at the input (they can measure all over the place, including 0uF) see below.
The old carbon composite resistors may have drifted a little bit with age and they were only 10% tolerance in the first place, but personally wouldn’t be too fanatical in this department. They have their own (low-inductance) charm. (If you want to check their value, do not stress them by de-soldering , rather cut off an adjacent track or smth to isolate and measure the component ”in situ”).

Tools? One mainly needs a sturdy soldering iron and a cable stripper.

1. The switches and every piece of cable belonging to the ”speaker option” and ”self bias” option should be removed. The switches for better performance, the cables rather for simplification, ease of access etc. Nobody today would use the SB option or connect this box to his/her main stereo/speaker setup!

2. All joints should be soldered. There are many of them, both in the cups, and in the energizer. For this operation the main component board of the energizer must be removed from the box, of course. But to begin with it is possible to remove the switches without that (”from above” so to speak). Just set the switches to the right position and notice which cable belongs to which ”active” contact point, and then remove and solder together these cables, in pairs. Then remove and throw away the switches and the superfluous cables and bits.

The soldering pins on the component board can be pressed out/removed by a reasonable sturdy soldering iron, and replaced by the stripped cable end.

3.Replace the 4uF el cap at the input w film type. See picture. 4uF polyprop 5% for engines are very cheap on eBay, but feel free to waste money on audiophile boutique stuff..

4. The cups. Some kind of fibrous material should be used for dampening, imo. Prolly more effective than foam. (Any old, disintegrated foam must be removed carefully, of course). I would cover the high voltage parts (with isolation tape) and fill the outer cups with dampening material also. Some holes in the connection board could be considered. (In my cups they looks like Swiss cheese).

5. If these were to be used a lot, one rather should replace the extremely stiff (of age) an microphonic headphone cable with for example Stax or ESP950 extention cables.

6. Pads. See previous post.

 

Wow! Brings back memories. I was a junior in high school when these came out. After hearing them I was in complete gadget lust. Unfortunately, I didn't have the wherewithal to acquire a pair. Besides the amazing sound, I remember the liquid filled pads.