Phaser Software Overview and History

Phaser is an advanced pulse and signal generator for E-Stim. Used together with our reference step-up circuit, Phaser provides a stimulation experience that goes far beyond off-the-shelf solutions.
The unique DynaShape pulse enhancer improves the frequency and pulse response, and level bars show the sum and difference, or the left and right peak levels of the stereo output channels.
Phaser can be remotely controlled through an Internet connection using its unique and safe PRP protocol. Besides the remote control functionality, PRP also provides secure chatting and can detect other Phaser clients connected to the Internet.

Waveforms
-->  Sine, sinusoidal, 0Hz ... 20,000 Hz, Sample Rates: 11, 22, 44 kHz
-->  uPulse, uni-directional, 0...9,800 Hz, Pulse Width: 50, 100, 200, 300, 500 us
-->  bPulse, bi-phasic, 0 ... 9,800 Hz, Pulse Width: 50, 100, 200, 300, 500 us

Modulation
AM, FM, 180 º Phase switching, Ramp

Sessions & Templates
32 editable sessions, 18 predefined templates

DynaShape
Frequency response 0 ... 22,000 Hz, Scope-functionality for pulse response
Auto-setting of pre-emphasis filter, Input level bars 0 ... -60 dB

Visualizer
Animated viewer for waveforms

Networking
P2P Chat and Remote Control, encrypted
Relay Server based Chat and Remote Control, encrypted
IRC based Phaser Finder

Requirements
-->  Windows PC with Pentium processor
-->  Full duplex sound card for frequency / pulse response measurement
-->  Windows XP or later
-->  A working Internet connection for installation and to use the PRP services
-->  Screen resolution of 1024 x 768 or greater for Remote Control

The History of Phaser

The first public release of Phaser was version 1.10, released May 15th, 1999. This early version was nothing more than a simple wav file creator, which we were inspired to by the legendary wg32 software of Allan Sydvall. He had published wg32 on April 13th, 1998 on his website, which is still online. One drawback of his tool, running in a DOS box and controlled by a bunch of command line parameters, was that it built just mono files. We decided to code a stereo tool, and that's how Phaser 1.10 was born. The output were wav files, and you had to use a third party player for playback.

In the beginning of the year 2000, Wolfie Buckleton published the StereoStim Wave File Player on his website, a player that could organize and play wav files using scripts. It had the ability to fade in / fade out the files, and quickly got popular. The latest version 1.21 is dated July 2000, and that was the last version ever, as Wolfie shut down his website.

Phaser 2.0, released by the end of 1999, could create and play wav files from a playlist. This playlist (or session file) was a plain text file with just the parameters and settings Phaser needed to build the wav files. You could easily e-mail or post these small session files, no need to transfer megs of wav files anymore. Phaser 2.0 also introduced the EFV (Enhanced File Validation) feature to quickly validate wav files against a session file. Phaser now was a real all-in-one tool, but still lacking the ability to generate signals in real-time.

Phaser 3.0 was a big step towards the real thing and was released on October 3rd, 2000. It had been hard work to make Phaser run in real-time on our 60 MHz Pentium test system. After days of tweaking and tuning, real-time signal generation finally worked on that old Pentium box. It was Jeremy [gCk] who had done the job by analyzing the time-critical routines and replacing them by optimized assembler code. Shudder!
It took another year and many bugfixes until we released the final version of Phaser 3.0 in August 2001.

Phaser 4.0 was a real challenge. We wanted true remote control with audio signal output on both sides, we wanted secure (and thus encrypted) network traffic, we wanted an integrated chat, and we didn't want to operate and maintain servers.
What we got was a P2P based solution that works without a centralized server, using some IRC functionality to find other Phaser users on the Net. And we got a server, too. The Phaser software itself can act as a server, so everybody may decide to run his own Phaser Relay Server, allowing other users to login and chat, and remote control other Phasers. We really liked that concept of making Phaser users not dependent on servers operated by us, thus rendering the product useless if the server operator decides to shut down his services.

Phaser 4.0 also introduced the Visualizer, an animated waveform viewer. Also new was the dynamic phase switching mode, and an even more optimized signal engine, allowing Phaser to run smoothly on real antique machines like Pentium I.
Phaser 4.0 can read Phaser 2.0 and Phaser 3.0 session files, but now employs an enhanced format for saving session files, thus shrinking the filesize by more than 50%.

Phaser 4.2 was released by the end of 2007. It was an intermediate release to mainly fix some issues with Windows Vista. Phaser 4.2 also introduced a new licensing scheme that allows easy reinstallation and instant activation of Phaser. Product activation would be required after reinstallation of Windows or after an upgrade to new hardware. With the new scheme, users just need to run the Web-based installer to instantly activate their copy of the Phaser software. The new activation scheme is not available to Windows 98 / ME users.

Phaser 5.0 really marks a new era in the history of the software. The signal engine was recoded to integrate the DynaShape filter, and the code was further optimized to again lower the cpu load.
The DynaShape module also allows to review the frequency and pulse response of a step-up circuit, and the pre-emphasis filter greatly improves the overall performance of the circuit.
The new level bars show the peak levels of the output signals and can be set to also display the sum and difference of the two channels.

Phaser 5.2, released in April 2009, mainly improves and extends the DynaShape module features. Phaser now can compensate for the frequency response deviation of the sound card, i.e. small errors that would bias the results of frequency response measurements. This is done by running a calibration sweep with a loopback cable in place.
We also replaced the built-in templates with new ones, now more focusing on LDC pulses. The old Phaser 3 and Phaser 4 templates were added as session files.

The optimized frequency response of a complete step-up circuit is shown on the right. We used the pre-emphasis filter of the DynaShape module to flatten the frequency response. To accurately reproduce the original stimuli, a flat frequency response characteristic is essential and required. Different transformers will require a different adjustment of the compensating pre-emphasis filter, so let DynaShape do all the work!