ErosTek ET312B Power Unit

Whether you’ve been into electrostim for awhile or are just getting started, there is something to be said about having the best and safest equipment. Until now, there was no single device that offered the power, safety, and ease-of use of the ET-312. American designed and crafted. Not a repackaged TENS unit or signal generator. This instrument is the result of over 3,000 hours of focused design effort, with one single end in mind. . .

E-Stim Excellence!

There are power units that sell for less, but none of them offer 18 pre-programmed modes — each designed by an experienced e-stim master to provide a variety of sensations all under computer contol without continuous knob twiddling. Each routine can be quickly selected on the bright, backlit display using 2 pushbuttons. Once selected, the tempo and frequency are easily adjusted using a single “MultiAdjust” knob, not two or more on other power units. And the intensity level is easily adjusted using separate knobs for channels “A” and “B” with the current levels clearly displayed at all times.

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53 responses to ErosTek ET312B Power Unit

  1. stephen

    bought two weeks ago et312 stimmulation power box
    it came with a Eroslink for windows 98SE-XP
    can it be installed on a vista computer
    have tryed to install it on the visa
    but it wont accept the software
    id be very gratfull if you could help me

  2. stephen

    thankyou for the information for the Eroslink to be installed on vista pc
    ive now download the software
    now the et312 is up and running
    once again

  3. Jeff Gord

    Hi there
    I am wondering what the specs are for the output plugs that go into the A and B outlets on a ET-312

    Model ET-312B Series 2903

    They are not a standard 1/8 (3.5mm) phono jack. That does fit but is is a sloppy unreliable fit.

    Jeff Gord

    • erostek

      Hello Jeff:

      All ErosTek units including your ET312B use a standard 1/8″ (3.5mm) diameter mono jack for their output connections. If your ET312B is not holding on to the leadwire plugs reliably, a couple of things may have happened:

      • Your leadwire plugs are damaged or worn out
      • Your output jacks are worn from many years of use

      In either case, we have replacement leadwires for sale and can also replace your output jacks. Please contact SexTek Support for more information about getting your ET312B jacks replaced. We can also replace the battery if needed at the same time.

      I hope this helps!


  4. Bill

    Alright, I’m getting intrigued. Still, I can’t bring myself to purchase something I haven’t tried. Does anyone have any suggestions on how to have some test runs to pave the way for me to then further research if there will be any long term negative consequences of using a device like this? Bottom line is, I love to cum and if this can prolong and intensify nutting well, all the better 🙂

  5. stephen

    Hello Doug
    i was using a pes for for many years untill i upgrade to a ET312 6months ago
    its the best move i have id done
    no wonder they call it a rolls royce system it’s the most powerfull on the market
    i love it,
    the pes would never match the et312 system
    anyhow i went back on the pes for one night and could not handle it
    in fact it was torture thats not stimming
    no enjoyment
    so as i said you wont get better than the ET312
    should have bought one years ago
    and we all know its expensive to buy
    but its well worth it
    all the best

  6. Trojanhorse

    Need to know both the frequency settings and voltages as we modify the programs.

    • erostek

      The frequency and output voltage varies depending on the program / routine selected and the type of electrode and loading resistance. Basically, all of our units have a maximum output frequency of about 300 Hz. The ET302R and ET232 portable units deliver about 40 volts peak-peak into a 100 ohm load at full power, while the ET312B can deliver 55 volts peak-peak into a similar load at full output in “High” power range. Output voltage will be lower with reduced resistance. The 100 ohm load is used for our testing purposes and is just a guide. Your application will most likely give a slightly higher or lower voltage depending on the load and how the voltage is measured.

      I hope this helps.

      =Eric Forbes

      • Trojanhorse

        Thanks Eric … that was very helpful. What is the current range 0 to ? mA

        • erostek

          Great! The ET302R and ET232 have a max output of about 120mA. The ET312B can do 180mA. The narrow pulses make current measurements tricky at best. The outputs are also fully balanced with equal parts positive and negative current flow over time. =Eric

      • Someone

        Hi ! I was planning to buy an ET312B but i have 3 questions:

        1) ET312 is known to be the best power unit, from what i can read on internet.
        But you said the maximum frequency is (only) 300 Hz :/

        I am used to using “Performer I” and i know it can deliver a max frequency of 500 Hz. When i “play”, i increase progressively the frequency. At the end there is a kind of “jump” the frequency jump from 400Hz (maybe, i dont know the exact value) to 500Hz. This jump is just awsome, the sensations at 500Hz are unique. Even if i play a long time , this frequency reains unique…

        So can you confirm me that ET312B delivers only a maximum frequency of 300 Hz 🙁 ?
        What about other power boxes ?

        2) I read that “channels are isolated”, do you mean isolated in voltage AND intensity AND frequency ?
        “Performer 1” was only isolated in voltage Intensity and frequency was handled by the same button for both channel.

        3) If you answer yes for question 1 about frequencies :
        Are the frequencies of channels synchronised, ? i mean… even if they are isolated… Do they use the same clock to generate signals ?
        Actually i wonder if two channels with the same frequency will be ALWAYS synchronised or if there will be a random phase shift between them ?

        • erostek

          Good questions! Here are some answers:

          1) The ET312B is not in the same category as “function generator” types of power units, including the Performer I, PES, and Folsom PSG-202 (among others). These units produce monotonous signals that repeat over and over again, with no variation unless controls are manipulated you, constantly. ErosTek units are designed for erotic play, and contain micro-controllers that are custom programmed to do what we want — produce varying waveforms that feel bigger than they are (due to the sharp edges of our waveforms and very narrow pulse-width, which gives the nerve endings ample time to recover) and are symmetric and biphasic for even distribution of current in the positive (+) and negative (-) directions over time. While the maximum pulse rate frequency is 300 Hz, this is just one spec. Taken as a whole, the feeling you get from an ET312B is fuller, more erotic, and provides a reliable source of pleasure to pain, tingling to hands-free orgasms.

          2) “Isolated” refers to the electrical isolation between each channel (A and B) and between the internal circuitry and anything you might touch outside the box. The current loops for each channel do not share a line in common, making it safer for use above the waist on the nipples (for example) where limiting current flows across the chest is a good thing.

          3) The outputs are usually independent of each other. One may be slowly increasing in intensity and/or frequency while the other is decreasing. There are many different modes on the ET312B, each having its own “flavor” — and Audio modes to allow safe conversion of high-duty cycle waveforms to be converted to low-duty cycle e-stim waveforms with full control of each output level and input sensitivity via the MultiAdjust (MA) control.

          I hope this helps. If you haven’t tried the ET312B, find someone to let you feel it first. Or, if you know you liked getting wired up, get it. You’ll wonder how you lived without it, especially if you already like the Performer I (which I have, and frankly, cannot compare to the ET312B or ET232).


  7. Harrad

    I am thinking about getting a second ET312B & I have a few questions. When you tie them together with the link cable, does the second just emulate the first? How do they know which is the controlling box? Are the channel levels still independant? Can you tandem more than two?

    • erostek

      Hello Harrad:

      When you link 2 ET312s together using the optional Link Cable, one is considered the “master” and the other the “slave.” In this configuration, the mode you’re in is controlled by the master ET312, which is followed in perfect synch on the slave unit. You can control each of the output channels independently (from each ET312) and the outputs from each channel (A and B) are ganged together. The ET312 remains an independent 2-channel power unit, with an additional output channel and output control when in linked mode. I hope this helps! =Eric

  8. Simon

    I’d like more info on making a DIY Wired remote. The manual talks about using voltage on the right audio input. Does that mean it cannot use it for audio input at the same time? It sounds like that is not the case the way it references using Audio mode 2. But how do you do both 2 channel audio along with the DC control voltage? Thanks!

    • erostek

      Hello Simon,

      The DIY wired remote allows a variable output from channels A and B by using a variable DC voltage from 0 to 1.5 VDC applied to the audio jack in Audio mode. You cannot also impose an audio program on top of the signal — it’s either a simple variable control of basic e-stim pulses (DIY remote) or more erotic possibilities using stereo audio files, music or material made for e-stim (via SmartStim, Phaser, Goldwave, or any other means). I hope this helps! =Eric

  9. Hogtie

    I have a 302R for years, and I am very pleased with it. However the is one thing that is a big limitation. The 302R stops working after 30 min of use when i “Audio” mode.
    I want to get me a 312B, but not if it have the same limitation. Dose it?

    Kind regards for a happy Erostek user

    :-)) Hogtie

    • erostek

      Hello Hogtie,

      The ET312B will stay ON as long as the power switch is left ON and there is sufficient battery power and/or an AC adapter connected.

      The ET302R will usually power off automatically after 60 minutes of inactivity — changing a mode or increasing the level will reset the auto-OFF timer, but I can see how you might not do this in Audio mode. There is no way to change this behavior, but it helps to keep from killing your battery in case you left it ON without realizing it.


  10. Chris Wise

    I bought a 312B some time ago.
    I have now finally started looking at files from the web’
    Apart from the MP3 player, can you please supply or advise what connecting leads that I need.
    If you can supply, please advise cost including postage via fedex express to Australia 5165

    • erostek

      Hello Chris – If you have the audio cable that came with your ET312B, that’s all you need to connect it to your MP3 player. If you can’t find it, we don’t yet offer a replacement online, but you can find one at your local Radio Shack or electronics / stereo store. Here’s a link to a compatible stereo cable from Radio Shack. In any case, once you have the cable, connect one end to your MP3 player’s headphone jack and the other end to the Audio jack on the ET312B. Select “Audio 3” for best results with stereo files and adjust the input sensitivity using the MultiAdjust (MA) control. A setting of 10 – 12 o’clock works best for most inputs. And then adjust each output channel (A and B) to suit your situation. That’s it! Enjoy. =Eric

  11. John Rice

    we have The Erostek 312 my unit das put out power till 60 we tack or time moving up slow 3 or 4 hr,but befor we are toped out at 100 how can I git more power,up grad or somethig I wish I had known about it a long time a go pleas let me know sow thing

  12. Glenn Wearsch

    Hi Chris,
    Could you tell me if you are still repairing ET312b’s that are out of warranty?
    If you do not, could you tell me where one would get this unit repaired? (Mine is still in warranty but the question has been brought up on Smart Stim web site and I would like to post the proper answer.)
    Thanks for your help in this matter.


    • erostek

      Hello Glenn.
      Thanks for asking about our repair policy. I just sent an email update to our dealers and have just posted a Repair Policy Update to the blog. As you’ll read, the vast majority of ErosTek units continue to operate flawlessly for many years when taken care of. I hope this answers your question and feel free to link to this post for anyone asking the same questions on =Eric

  13. Tom Langham

    I would like to make a set of tri-phase leads for my ET-312B with two mono leads, each with 3.5mm plugs. Will “common” be the two wires that are connected to the center contact or the wires connected to the side contacts of the plug?

    • erostek

      We generally connect the wires leading to the sleeve (side) contacts of each output plug together to make the common wire of a TriPhase adapter. It doesn’t really matter which ones you choose as long as you pick the same wire from each channel (tip or sleeve) which will preserve the phase relationship. ErosTek units produce balanced biphasic outputs, so both sides are equally active. I hope this helps. –Eric

  14. Douglas Carl

    Hi All

    I am a long time satisfied user of the ET 312B.

    (In fact, I also have one of the earlier ET 232 units.)

    I have had the 312 for a few years now, and lately I am noticing the batteries are only charging to around 50%.

    What is the output range for the charger? I am not sure if the charger or the batteries are getting weak.

    Thanks in advance for your help.

    Doug C.
    Sterling Heights, MI

    • erostek

      Hello Doug:

      I’m glad you’re enjoying your ET312B and 232. The battery inside the ET312 is designed to last a few years, sometimes 5 or more years if charged after each use.

      If your 312 has ever been discharged past the “Low Battery” alert (ex. power switch left on for a few days or more while disconnected from AC adapter), the battery will most likely need to be replaced. There are two kinds of AC adapters out there for the ET312B. The earlier units shipped with a linear / unregulated adapter that had pins for the US/Canada, UK, or EU hard-wired into the adapter itself. These adapters were rated 12 VDC at 500mA. The newer adapters are universal and can adapt to a wide range of input voltages (100 – 240 VAC) and come with 3 kinds of plugs that are fitted into the mains input: US/Canada, UK and EU. These regulated adapters have a rating of 15 VDC @ 500mA and have the new ErosTek logo on the back. Both have a center positive (+) polarity coax connector that fits into the ET312.

      If you need a new battery, we have them available. If you need more help, contact Thanks. –Eric

  15. Michelle

    Sometimes, a PES box will come with a weaker output than is normal. I have had several PES units and have had to send one back because it was obviously not up to par.
    Just sayin’
    Kind of wish I had tried a ErosTek unit too, so I could compare them side to side.

  16. Steve P

    I bought one from Regulation in London- it was delivered to Germany within a week. It is the most amazing device. Anyone thinking of buying one- my advice is an emphatic buy one NOW. Just tried triphase mode and it was mind blowing! it is not cheap but this device is worth every penny and more. I can´t believe I didn´t know about this device before. Thanks Erostek for the great work that went into making this device.

  17. jihel

    Is there a way you could have a battery that does not become unusable if accidentally discharged? It is really an inconvenience for a device that cost several hundred dollars. The battery is clearly a weak point.

    • erostek

      I recommend removing the black plastic cap from the power switch to keep the power switch from being pressed ON during transit. The current flow required by the ET312B made a manual switch more practical than a power management circuit with push button power switch (like the ET302R) and automatic power OFF. It would be nice to have an automatic power OFF feature, but that was not designed into the ET312B. Great product enhancement idea. Thanks for your feedback. –Eric

  18. Tim Hodgson.

    I’ve has two ET312 sets for several years and have had excellent service from them. Unfortunately the batteries are no longer accepting a charge. How can I buy new ones, and I’ll need instructions on how to fit them. Please help!!

    • erostek

      Hello Tim,

      Here’s the link you’re looking for. The Rechargeable Battery Module contains step-by-step instructions and can be done without a soldering iron. I hope this helps. -Eric

  19. Pete Plastow

    A few months ago you sent me a new battery for my ET312, it work for a while , now it will not hold a charge,in fact if left on charge for a day or to it only get up to 65% and cuts off when I use it for less than a minute. Can you end me a new battery and I will send this on back to you. Pete

  20. Hugo Patten

    I have bought 2 312’s this year (1 directly from you and the other from your recommended shop in NYC) and endorse all the compliments that others have paid your design. But I bought 2 so I could have 3 or 4 synchronized connections – eg prick, arse, nipples, bi-polar Wartenburg wheel (for a professional Domme). The link cable I use is the one you provide. But I cannot link them – whether I follow exactly the instructions in the manual or try numerous variations I always get the same result: “error 4 switch off power!”

    2 questions: 1) why the exclamation mark? Are the units being damaged until I switch them off? 2) What does the error message mean? Can I do anything about it?

    • erostek

      The cable supplied with your ET312 units is intended to connect and audio source (iPod or other portable mp3 device) to the audio jack of the ET312 for audio e-stim. To link two ET312s together for synchronized stim on 4 channels, you’ll need to get a Link Cable for ET312 available on our online shop. I hope this helps!

  21. Feels Great

    Got my ET-312 a couple of weeks ago, could not be more pleased. I have had HFO’s with Waves, Climb, Orgasm and Intense. There are spots in the Waves routine I wish I could isolate and just have them play continuously because they feel super nice.

    • erostek

      I’m glad you’re happy with your ET312! I’ve been enjoying Intense, Rhythm and Audio 3 when fed with the latest JT album, “The 20/20 Experience (Complete)”. Feels great and gets the job done every time. Enjoy. –Eric

  22. Steve Campbell

    Hi Eric.

    I got my 312B last January and love it, but I have a couple of questions.

    First, I wanted to know if it is ok to use the power unit when the battery is low and it is connected to the charger. I couldn’t find anything in the literature says yes or no about this.

    Second, both of my lead wires has failed at the black wire connector (they were not bent or damaged in any way). A replacement banana plug solved the problem but I wondered if you have heard of this.


    • erostek

      Hello Steve. I’m happy you’re enjoying your ET312!

      It’s perfectly fine to use your ET312B with a low battery while connected to the AC adapter. It will charge a bit slower but that’s OK. The lead wires tend to fail where they receive the most movement. We have not had a problem with the factory molded leads we’ve been getting and they last much longer than soldered plugs (due in part to the built in strain relief) but even these will eventually fail. We sell replacement lead wires and extra-long lead wires in case you need replacements.

      Thanks again and enjoy. –Eric

  23. Steve Campbell


    Thanks so much for replacing my leads, while it was not my intent to have you do this, I cannot but be pleased you did.

    And, to all who read this in the future, I want to say again that I am so very glad I chose to purchase my electric toys from ErosTek. If everything in life was even half as good as Eric’s customer service the world would be a much better place.

    Eric, you rock!


  24. Abbygail

    got a question i lost my power cords for my et312 erotek power box. can i go to radioshack to buy a replacment? or where can i get one.

  25. Anthony

    Hi, I have an ET312 unit and it’s stuck with the Battery Low indicator on. I’ve had the unit for almost 8 years now, and this is the first time I’ve had any issues with it. If the battery went bad, would the device still work if it was plugged in? It currently won’t work even when it is plugged in. I also noticed that if I leave it off and plugged in for an hour the device gets very hot now. I’m trying to figure out if it’s the battery that went bad or the charger. Any ideas?

    • Post Author

      Sometimes, the battery gets weak and you can still charge the battery but it has a much shorter run-time (1 – 3 hours vs. 8 or more). In your case, it sounds like the battery is beyond the point of charging and is putting a big enough load on the charging circuit to keep the 312 from running whether powered by the AC adapter or not. The loading also would explain why the unit is getting hot. In this case, the best course is to replace the battery with a new battery module and recycle the old one. It could be more complicated — including replacement of charging IC and/or AC adapter, but the most obvious step is to replace the battery. I hope this helps! -Eric

  26. Kim Turner

    I’m thinking of purchasing the ET-312B. Right now I use two PES power boxes connected in parallel to the same electrodes. This allows more than a “one note” experience. Would it damage the ET-312B unit if I connect it in parallel with the two PES units? Multiple inputs add depth to experience but I do not know what this might do to the ET-312B unit.

    • Post Author

      You’ll notice a vast difference in the sensations available with an ET312B compared to your PES power units. The built-in routines will give you a lot to experiment with! I’ve not yet heard of anyone connecting two units in parallel as you’ve described. I do not recommend connecting any other power unit or source to the outputs of the ET312B (or other ErosTek units) since they can disrupt the output stage(s) and potentially damage the output transistors. The ET312B uses a more sensitive output circuit coupled to a micro controller which tracks the output current through each channel (A and B) in real-time, so connecting an external current source will cause erratic operation. I hope this helps! -Eric

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