From E-Stim FAQ

ET232 and ET312B Comparison and Specifications


ET-232 Portable

ET-312 Advanced Dual Channel


2 Independent/Isolated

2  (Independent/Isolated) + Phantom 3rd Channel (TriPhase Output)


2 Blue Output LEDs

32 Character Lighted LCD + LEDs

Operating Modes

15 modes including audio and HiFrequency (300Hz) mode

18 – 12 normal, 3 audio, 3 tri-phase

Audio  Processing

TENS style modulation

Multiple Advanced TENS style modulation

Remote Control


2 output level controls, MultiAdjust control, 1 mode select/power control

2 output level controls, MultiAdjust control, 4 Tactile Input Keys

Dynamic Pulse  Technology Parameters

Dynamically adjusted amplitude, modulation, pulse width, rate, frequency, duration, power & more via the MultiAdjust (MA) control

Dynamically and manually adjusted amplitude, modulation, pulse width, rate,  frequency, duration, ramp, power, audio sensitivity & more

Output Waveform

Symmetrical AC True Bipolar

Symmetrical AC True Bipolar

Nominal Output Power

60 micro coulombs per pulse

80 micro coulombs per pulse

Output Jack(s)

2 x 3.5mm (1/8″)

2 x 3.5mm (1/8″) Heavy Duty

Pulse  Width

0 – 500 usec dynamically adjusted

0 – 500 usec dynamically adjusted


Built-in high sensitivity

Supplied external electret

Audio  Input

Built in microphone or line input (mono)

3.5mm stereo line, 10k ohms, 3 volts RMS max & 3.5mm mono microphone

ErosLink Interface

3.5mm Link Jack – info

3.5mm Link Jack – PC and Mac OS X

Disposable Battery

Standard 9 Volt Alkaline

Rechargeable Battery

12v High Capacity 1000 charge cycles

AC Power

UL Listed 12 volt Adapter/Charger

UL Listed 12 volt Adapter/Charger 400+ma

Battery Life

4 – 8 hours (alkaline)

4 – 48 hours

Dimensions (approx.)

3.3″ wide, 4.4″ long, 1.5″ high

8″ wide, 6.75″ deep, 2.5″ high

Weight (w/ battery)

8  oz

2 lbs 14 oz

Shipping Weight

approximately 2 lbs

approximately 5 lbs

Supplied Accessories

AC adapter/charger, 9-volt battery, two banana plug output cables, color user guide

AC adapter/charger, microphone, two banana plug output cables, audio cable, 22 page user guide


ErosLink2 software

ErosLink Software Package, Link Cable, International AC adapters

Installing ErosLink on Vista

Installating ErosLink

ErosLink for the ET312B runs on Windows 98ME through Vista. Refer to the ErosLink User Guide for more information on installing and using this software.

If you are using our USB to Serial adapter you need to upgrade the USB driver for Vista after installing ErosLink using the CD. After downloading and installing the update, you will need to restart your computer in order to refresh the USB driver.

Assembling the Cable

The serial link cable connects to the USB adapter via a 9-pin “D” connector and is secured with thumb screws. The USB cable is connected to an available USB port on your computer. The mini plug end is plugged into the Link jack of your ErosTek ET312B.


It’s a good idea to connect the cable from your computer to the ET312‘s Link port with the ET312 OFF, then turn it ON just before launching ErosLink to make sure it has a fresh start.

Also, make sure that the front panel of the 312 is positioned so that the jacks are properly lined up with each hole. Sometimes the panel may vibrate enough during shipment to obscure the Link jack. Pressing inward on the front panel while moving it side to side often makes it slide into place and remain there.

If you have any problems installing ErosLink, please let us know.

Do you have an ErosTek ET312B and want more information about ErosLink?

Stereo-Stimming with your ErosTek ET312B

There are two camps, two divergent ways of using stereo audio tracks to produce erotic electrostimulation: one is cheap and the other is much safer.

The Cheaper (and more dangerous) Way

This is the way I got started years ago. When I was still in high-school, I didn’t have an ET312. No one did. It was 1982. I had an awesome Lafayette 4-channel amplifier and an IBM PC that was capable of producing crude tones from its onboard signal generator. I connected the audio output of the PC to an unused audio input of my stereo amp and connected the speaker wires to pieces of aluminum foil and solid copper wire attached to my skin: cock and balls. I was just 15 years old. I didn’t know about ground loops or that the amplifier was designed to couple with a different load than I was presenting it with. It didn’t matter. I was a geek and I was horny. I wrote a simple BASIC program on the PC to make musical tones, amplified them and applied them to my cock and balls. It felt great! Until I got numb. That happened in less than 5 minutes of use. Bummer

I didn’t realize that I was zapping my nerve endings big-time.

It turns out that audio waves are more or less continuous in nature. They can be represented as a sum of one or more sine waves which when added together, produce a signal of varying complexity and tonal character. Even though my PC was making square waves (which were really edgy and beefy, another reason why I was getting numb so quickly), the end results of using audio waves through a stereo amplifier are usually:

  1. too much current is applied to your body,
  2. the current is not well-isolated from the AC line voltage,
  3. you’ll have a numb and tingly feeling wherever the electrodes were (sometimes up to 24 hours later).

But it’s cheap. Everybody has an amplifier. Some users have made strides to make stereo amplifier e-stim safer through the use of isolation transformers and resistors. Better but still not much safer. Nothing beats a device made to be used for the job it was intended. Stereo amplifiers are made to produce sound using speakers. The ErosTek ET312B was made to produce pulses that feel great when you connect them to your body.

Since the early days, I’ve experimented with isolating the outputs (using transformers) and series resistors (to limit the current) and low-duty cycle waveforms (to limit the average power delivered to my balls) but I still can’t get over the problems inherent in using a stereo amplifier for erotic e-stim purposes. It’s difficult to decide where to set the outputs for each type of wiring configuration and audio track used, and it doesn’t feel better than an ET312B running in Audio 3 mode with a well-prepared stereo-stim audio track being played into it. So I’m proposing…

A Better (and safer) Way

I’ll admit that I get to experiment a fair amount with e-stim these days. I’ve been playing with the ET312 for about 10 years and the newer ET232 especially when I’m traveling (because it’s smaller and lighter). And lately I’ve been discovering the joys of stereo audio e-stim especially using some of Mr. Terminator’s (aka naughtyelectron) files he calls the “Pulsinator Suite.” (Read my post touting the joys of these files with links to the download site.)

But why is e-stim safer with a made-for-play device like the ET312?

For one thing, it has been designed to be connected to a human body (not a speaker). That one distinction causes its design to be made more like a medical TENS or EMS unit and less like a consumer grade audio amplifier. It has isolated outputs using transformers, current limited operation by way of sensing resistors and a micro-controller that continuously monitors the outputs for proper current levels. And it gives the user better control of the output via dedicated output controls for each channel and output LEDs that glow in proportion to the output signal being generated by the processor.

The waveforms themselves are different too. They consist of very narrow pulses not at all like the ones used for making sound waves and sound edgy and thin if you listened to them. But they are just what the nerve endings like, as one tiny pulse is sensed as being there much longer than it actually is, the nerve endings get exposed to less current over time, can recover much faster once the current is off, leaving you tingling only when you’re wired and stimming. Of course, I can tell you from experience that stimming at very high levels for prolonged periods of time will leave you with a tingle for a few minutes or so after you stop stimming, but it’s nothing compared to a single session using a stereo amplifier. Seriously.

Now back to the (audio) program…

If you have an ET312, it’s easy to vastly expand its capabilities using a few common household items:

  • an internet connection with browser
  • an iPod (or other mp3 player) -or-
  • a music application like iTunes (or similar)
  • the stereo cable that came with your ET312B

The first step is to find some audio files to stim with. There is a forum out there called SmartStim that has some very dedicated users that have created and uploaded a variety of stereo files for your enjoyment, all free using your browser. You might be browsing for awhile though. You have to be wired up and playing the track to really know what it’s going to feel like, and that takes some time. So, leave yourself a block of time to peruse the library of files you’ll find there and make a few playlists on your music player (iPod) or application (iTunes) to keep the ones you like in the order you enjoy most.

But we’re jumping ahead just a bit.

First: find some tracks (see my post for a starting point or our AudioStim category for lots more). Then: download them using your browser. Next: import them to your music player like you would any other music file.

Get Wired!

Connect yourself in a comfortable configuration with your ET312B. It helps to use both channels (A and B) when doing stereo e-stim since both the left and right channels will be engaged and nice things happen when you can feel the effects of one channel playing alongside the other.

Wired up? Okay. Make sure your configuration is working by testing it using one of the ET312’s factory routines (like “Waves” for example).

  • Connect one end of the stereo audio patch cable that came with your ET312B to the “Audio” jack on the front panel.
  • Connect the other end of the cable to your iPod or computer’s headphone output.
  • Set each output level on the ET312 to a minimum.
  • Set the MA control to 12 o’clock.
  • Press the [UP] button several times until  “Audio 3” is displayed.
  • Press [PLAY] on your iPod or iTunes player to start the audio track.
  • You should see the red LEDs flashing for each channel as the track plays.
  • Adjust the MA control so that the LEDs flicker without being off or on all the time (you can adjust this during e-stim too)
  • Slowly increase the output levels for A and B until you begin to feel the stim
  • Adjust the MA control as needed to match the output level of your music player or computer.

A little involved? Yes. But worth it? Definitely. I’ll add some pictures and a video showing the steps illustrated above in a later post. Now, I have to test some of those new tracks I found and write about my results. Stay tuned.

Frequently-Asked Questions

Frequently Asked Questions (click for the answer):

How safe are ErosTek devices?

How do ErosTek devices differ from medical devices?

How much current do ErosTek products deliver?

What version of ErosLink software works with the ET-232?

Can I order direct from ErosTek?

Why do your products cost more than others?

Do your products have enough power for BDSM Play?

Just what is “Dynamic Pulse Technology”?

What all can I connect to the audio input?

What accessories can I use with ErosTek products?

We’re a dealer, what is your wholesale pricing?

Q: How safe are ErosTek devices?

A: Because medical e-stim devices such as TENS and EMS devices have a excellent track record for safety, we built upon the same technology used in medical devices and the research that has gone into making them safer. E-stim, however, isn’t without risks and there are some people who shouldn’t use any e-stim device. See our Safety page for more information.

Q: How do ErosTek devices differ from medical devices?

A: While our products use a similar basic waveform compared to many medical e-stim devices, they are NOT designed for treating any sort of medical condition and should not be used for such purposes.  Medical devices were not designed to be erotic, and our products were not designed to treat medical conditions.  Nearly everyone finds our products far more erotic than medical e-stim devices.

Q: How much current do ErosTek products deliver?

A: The simple answer is our products can deliver a lot more current than TENS units and most competing products. Very few of our customers use the full output of our products. The more detailed answer is medical devices use constant current output circuitry that allows for consistent medical e-stim (i.e. a doctor can prescribe 40 milliamps of TENS therapy for 30 minutes per day) that makes it easy to specify their current output. We found constant current e-stim doesn’t feel as good and it’s also not as safe for erotic use. For that reason, our products dynamically adjust their output current to best suit how they’re being used. That makes them feel better and automatically deliver more or less current as required. It also makes it much harder to specify the current output because it depends on how the device is used and how the measurement is performed.

Q: What version of ErosLink software works with the ET-301R or ET-232?

A: I new version of ErosLink for the ET-232 power unit is actively being developed.

Q: Can I order direct from ErosTek?

A: Sorta. SexTek (our brother company) is the factory-direct source for ErosTek units and high-quality e-stim accessories.

Q: Why do ErosTek products cost more than some other erotic units?

A: We simply put a lot more into our products. Our units typically do more than 2 or 3 other units combined.  They also typically cost several times as much to manufacture. Our ET-312B out the door weighs about 5 pounds. That’s a lot of hardware. Our profit margins are actually lower than most of our competitor’s.

Q: Are your products powerful enough for S&M use or are they mainly designed for pleasure?

A: We’re proud of the fact our products do both very nicely. Most users never come close to using the maximum power settings.  Yet our products can also be highly erotic.

Q: Just what is “Dynamic Pulse Technology”?

A: It’s a proprietary method of generating erotic waveforms in the digital domain.  The result is greatly increased variety and unique erotic sensations. You can read all the details in our Technology section.

Buyer’s Guide

Confusing Choices…

There are lots of e-stim options. You can choose from devices designed for medical use (like TENS and EMS units). There are also devices marketed direct to consumers for massage and “body toning.” Other people try to adapt devices never intended for human e-stim. Finally, there are units especially designed for erotic use. This section discusses the various options and things to consider.

TENS and EMS Medical Devices

TENS units have dropped in price making them a common choice for erotic e-stim. While they can be used for this purpose, most people don’t find them especially erotic. This is because they were designed to desensitize nerves (for pain management) rather than provide erotic stimulation. EMS units are designed to cause muscle contraction and are also far from optimal for erotic use. Both suffer from a limited number of modes and variety. Some of the newer, less expensive units being marketed direct to consumers also lack a proper bipolar waveform and do not have fully isolated outputs. You get what you pay for, and where your genitals are concerned, you might want to think twice about trying to save a few bucks?

Electro Massage/Body Toning Devices

An increasing number of e-stim devices are being marketed direct to consumers rather than to medical professionals. Most of these are “body toners” or “electro massage” type devices. They vary widely in quality and capabilities, but most suffer from a very low power output–often too low for erotic use. Many are also very cheaply made, lack bipolar waveforms and are missing important features.  And, like the medical devices, they were not designed to be erotic in the first place.

Homemade or Adapted Devices

Some people, usually in an effort to save money, try to build their own e-stim devices or adapt commercial products that were never intended for human e-stim–like animal training products, hand generators, transformers and audio equipment. These devices generally use high duty cycle waveforms, which is the opposite of what you want for e-stim. They can easily cause various kinds of damage to the body or even death. We know of several people who have suffered lasting harm from trying to use these devices for e-stim. Given all the serious safety issues, they’re simply not worth the many risks!  Always use devices designed for use on the human body even if they’re not ours. [Read more about stereo amplifier e-stim.]

Analog Erotic E-Stim Devices

A few manufactures have designed products specifically for erotic e-stim. Nearly all of these are based on a very simple analog design that dates back to the 80’s. The stimulation simply turns on and off at an adjustable rate. These products have few advantages over less expensive TENS units and, in some ways, are often inferior. Regardless, most people who buy them end up wanting more variety. Many also end up wanting more intensity although at least one model packs quite a punch.

Digital Erotic E-Stim Devices

We’re often asked “what’s so great about digital e-stim?” The answer is simple: Variety! Instead of a device that can only turn the output on and off over and over, a digital device opens up a whole new dimension. We like to compare it to playing the same note over and over on a piano versus playing real music. Which would you rather listen to?

By producing waveforms in the digital domain, and including a powerful microprocessor, our products can deliver vastly more complex stimulation. The output can be constantly changing and choreographed between multiple channels. It’s simply a night and day difference.

ErosTek pioneered the use of digital erotic e-stim in 1999. Since then, a few others have come and gone with digital products.  They say imitation is the sincerest form of flattery. If you’re interested in purchasing erotic e-stim equipment, you might want to consider the following points before you make your decision:

  • Ease Of Use:

    Ease of use is important. The lighted display on our ET-312 tells you what’s going on in plain English and our remote units have a lighted numeric display. Most of our products use simple controls to set the stimulation intensity which are easier to use than Up/Down buttons and make it easy to rapidly turn down the level if there’s a problem.  Finally, our exclusive MultiAdjust control makes fine tuning very easy. It automatically lets you adjust the best parameters for each mode.

  • Type of Waveform:

    Nearly all the competition is still using an asymmetrical waveform. While this makes their units cheaper to produce, it yields inferior "lopsided" stimulation and there's scientific evidence it may not be as safe. All ErosTek products use a medical grade fully symmetrical bipolar waveform.  It's a difference you can feel and offers additional peace of mind. See our Technology section if you're curious why symmetrical waveforms are important.

  • Maximum Power & Frequency:

    Small hand held units that run off a 9 volt battery are inherently limited in the types and intensity of output they can produce. While our small units use 9 volt power for portability, we’ve learned the very best waveforms for erotic e-stim require a bigger power supply. The battery powered ET-312 uses a large internal battery and the unit weighs nearly 3 pounds. It’s simply in a different league altogether.Even in our 9 volt powered units, we use exclusive Dynamic Pulse Technology to use the battery power as efficiently as possible.  Many customers say our 9 volt powered units simply “feel better” and also offer more intensity than the competition’s products. The ET-312 is the only unit we know of that provides the same output regardless of the battery’s charge level. With others, as the battery runs down, the maximum output power falls with it.

  • Number of Settings & Variety:

    Most competing units have only a few unique operating modes. Variety is the spice of life and it’s especially important for e-stim. Our remote-controlled ET302R gives you 10 unique modes, our ET232 gives you 15 modes,  and our ET312B gives you 18 or more (via optional ErosLink software).

  • Audio Input:

    Audio-based stimulation can be really fun but most units lack audio capabilities–something we introduced to the world in early 1999. If you haven’t tried audio-based e-stim, you don’t know what you’re missing! We’ve further refined our exclusive audio technology in the ET312B and the microphone is built-in on our other products.

  • An Eye Towards Safety:

    Not only do all our products use a medical-grade bipolar waveform, but they all have fully isolated outputs which helps prevent dangerous unintentional current paths in the body. Our products use current limited outputs and duty cycle management to limit maximum power levels. We also incorporate fail-safe circuitry that helps prevent dangerous output levels even if a critical internal component should fail during use. Finally, the microprocessor in our products performs a self test on every power up. If any problems are found, the unit displays an error code and shuts down instead of risking unsafe operation.

  • An Experienced Manufacturer:

    ErosTek has over 10 years of digital erotic e-stim experience. We've also learned a lot since we introduced our first model. We're already working on our fourth generation products. This is a very small niche market and some competitors have already come and gone. Will you be able to get your expensive unit repaired if the manufacturer is no longer in business?

  • Value:

    Our products contain more advanced technology and more features than any offered by our competition. Many of our customers own half a dozen e-stim power units and, after buying one of ours, never use anything else. Two of our products easily offer more variety than 3 or 4 other devices combined. We suggest you shop carefully and you might want to read what others think.

  • Not Sure What to Start With?

    Starting out with erotic e-stim can be challenging given the variety of power units and electrode accessories available. We have a few ideas to get you started:

    1. Check out our ready-to-go Package Deals featuring the ET312B and ET232 power units and an assortment of our most popular electrodes and accessories to get you off in the right direction.
    2. You can always contact us via our Support Page if you need help deciding what to buy or need help after your order arrives.

Emails Answered: Internet Control of ET312B?

Date: August 22, 2008
Hello ErosTek,

I was reading about your ErosLink software and read “We’re even working on software allowing real-time control of the ET-312 over the Internet–giving “cybersex” a whole new meaning.”

When will that be available?



Hello B.,

Currently, we do not have software that can control the ET312 over the internet and we are no longer developing this feature into our software.

I’ve heard that there is a download on SmartStim ( that would allow you to control the unit over the internet using the ET312 audio input.

I am not sure if it is still available.