THE ULYSSES ENERGIZER
Minimum Recomended Amplifier: 20 Wrms Per channel into 4 Ohms
Input Wire Guages Accepted: 12 to 24 AWG
Input Resistance: 5.2 Ohm
Input Power Rating: 20 Wrms
Max Burst Input Voltage: 18.5 Vp
Max Burst Input Current: 2 A
Max Output Voltage: 1000 Vp-p
Max Bias Voltage: 240 V
Max Slew Rate @ 10 kHz & 100 Vpp: 3 to 4 V/us
Max Loading with Stax SR-303 @ 10 kHz: 0.99%
REQUIRES EXTERNAL AMPLIFIER
FEATURES
The Ulysses Energizer has many highly desirable features that make it not only the cheapest option for powering your electrostatic headphones by an enormous margin, but one of the best options as well. Its three crowning features are its Transformers, its ultra low noise bias, and it's best in any class safety features.
TOROIDAL TRANSFORMERS
The Ulysses is the only energizer of any kind or brand to use toroidal core transformers. These present some strategic advantages over their E core siblings. They are more efficient, and they have far less flux noise due to their mathematically almost perfect form. Because of this, they do not leak flux, meaning there is no cross talk despite the energizers' highly compact package.
ULTRA-LOW NOISE BIAS
The Ulysses uses multiple tricks to get one of the best high voltage biases in the industry. It uses state of the art Toshiba SiC diodes for virtually no switching noise. It has two separate biasing circuits to eliminate cross talk and improve bias stability, and each channel has it's own 1uF Panasonic film capacitor.
VAST QUANTITIES OF SAFETY FEATURES
It is no secret that electrostatic headphones cost a lot of money, and are very delicate. Because of this, making sure that the energizer you plug your headphone into is safe, and won't blow your diaphragm to smithereens is very important. To match its obscenely cheap price, the Ulysses has obscenely overbuilt safety features, such as input voltage and current protection, bias overvoltage protection, two separate layers of output overvoltage protection, and 8 high-voltage current limiting metal film output resistors.
PERFORMANCE DETAILS
The oscilloscope image you see is displaying a 10 kHz square wave input to the amplifier at 50 Vpp. As you can see, it is not very square shaped anymore. Although this is not optimal, this leads to a far better listening experience than other energizers on the market, which have a very unpleasant 30 kHz ring. Although this is far beyond the realm of human hearing capabilities this ringing negatively effects audible high frequencies; Making them sound grainy, and pitchy, and fatiguing. This also reduces the sound stage, and impacts imaging.
This tradeoff to remove the ringing at the cost of capacitive attenuation pays off, as although the high frequencies are reduced, they are not distorted.
The graph pictured is voltage peak, measured as a function of frequency with a sine wave. This was measured unloaded, and before the measurent was taken, the energizer was set to hit a 50 Vp 10 kHz square wave.
As you can see, volume rolls off into the high frequencies, reaching 40% attenuation by 20 kHz. But, you can also notice that there is almost no attenuation in the base frequencies.
This is the best visualization of tradeoff of the transformers I chose to use, and another reason I believe that this tradeoff was worth it
The high frequencies can be EQ'd back in as long as your amplifier is powerful enough. Or you can simply choose to not too, as the existing frequency response pairs very nicely with intrinsically high frequency emphasizing electrostatic headphones, and will make them much easier to listen to for extended periods.
Although it is possible to make an energizer that does not experience these tradeoffs, the cost would be so egregious that it would be a better idea to simply buy a direct drive amplifier.
WARRANTY
If your energizer breaks, email Estatrons warranty office at warranty@estatron.com. You should get a reply within 24 hours. The cost to have your energizer repaired for you is $25, plus shipping both ways. Make sure to include everything that was originally in the energizer when you first got it. I will charge extra for missing original parts. The manual and original packaging do not count as original parts. The time to get it repaired can be anywhere from 1 day to multiple months depending on parts availability and shipping times. I will do my best to get your device fixed as quickly as possible.
To save money and time, you can purchase replacement parts directly from Estatron or, in select cases, other retailers.
This warranty will only cease to be active when both the paper it is written on, and the energizer itself, are cast back into the celestial fires from which their atoms were first forged or if Estatron LLC goes bankrupt, whichever comes first.
If your electrostatic headphones begin to experience repeated and consistent malfunctioning of the diaphragm, characterized by excessive hissing, bussing, popping, loss in volume, or channel imbalance, and you have already attempted contacting the original manufacturer of the
headphones and had your warranty claim denied, then this warranty will also apply to your headphones, and you can send them to me to have a new diaphragm installed.
Please keep in mind, if you do this, although I will do my best to ensure a very
high quality and long lasting diaphragm, with good channel matching is installed, your headphones will not sound the same as before.
I do not have access to the original specifications that your headphones’ diaphragms were made to, nor do I have the original materials or equipment. I will offer different choices of diaphragm material and tuning if I can, but I cannot guarantee anything.