[Tutorial] Building your own DIY E-Stim Stereo Device

[JakofClubs]

I find my best electrodes are 3D printed in Protopasta Electrically Conductive composite PLA filament,

Any chance you could share the .stl files for your electrodes and the setting you use to print? I have a 3d printer on the way right now.

[Tekkkie]

Optional for electrode, with those simple 3 things you can build a lot of cables for different setups:
10x 2pin cabels for having enough 2pin connector - 11.92€
40x Banana 4mm pins (Box set) - 9.50€
1x 25m thin speaker cables - 8.49€
1x 2m silicon loop - 12.99€ (I can personally recommend this seller)

Any further instructions on how to make decent starter electrodes with these components?

[Electro]

I find my best electrodes are 3D printed in Protopasta Electrically Conductive composite PLA filament,

Any chance you could share the .stl files for your electrodes and the setting you use to print? I have a 3d printer on the way right now.

I can't design anything, I really just resized the crap out of bracelet type files on thingiverse to fit me, but for a decent head electrode, there is a 0shiri stl series for a cum catcher device and I printed the version 2 with the breakaway supports in the head area, but the conductive PLA doesn't like to be twisted because the conductive material makes it weak at the layer lines so I had to reprint and use a soldering iron to melt them away. I usually print in normal PLA for sizing and fit and once I feel it will work, I print in conductive PLA and then use a soldering iron to carefully push a spread out stranded wire strand bundle into the print in a thicker spot while supporting it from the back to prevent it from deforming while it melts in.

[harryc]

This ones for all you E-Stim lovers out there from the wonderful place we call the United Kingdom!

Finally after a year of umming, arring and wondering if I could do it, I did it
And let me tell you, it's magcal. Going from a bogstandard tens machine to this thing was bloody awesome!
Thank you so much for the comprehensive and easy guide @lolol2
You really are a miracle worker

PSA: I definately did things you shouldn't do ie: melitng holes in my plastic with my soldering iron and I definately bought parts you could live without but I'm no expert and it works for me so I call it a success for the time being

Anyway, without further a-do, lets get into the parts list

Parts:
- Amplifier (https://amzn.eu/d/0BUDNmh)
- 2 x Transformers (https://cpc.farnell.com/eagle/p634t/100 ... dp/LS01701)
- Volume Control Knobs (https://amzn.eu/d/bZ2jBV7)
- 3.5mm cable for amp (https://amzn.eu/d/eKwdMBW)
- Heat Shrink Tubing (https://amzn.eu/d/3nRBLIv)
- Banana Plugs + Connectors (https://amzn.eu/d/b5pwlGm)
- 2 x 50W 4 Ohm Resistors (https://amzn.eu/d/3rh0MvP)
- 2 x 50W 22 Ohm Resistors (https://cpc.farnell.com/welwyn/wh50-22r ... dp/RE03497)
- Plastic Project Box (https://amzn.eu/d/amyk1Rz)
- 0.5mm^2 Cables for Wiring (https://amzn.eu/d/2PoR1LQ)
- 4 x Rocker Switch (https://cpc.farnell.com/auto-bar/412rd/ ... dp/SW06094)
- 2 x RCA Chasis Mount Sockets (https://cpc.farnell.com/pro-signal/psg0 ... dp/CN21179)


Exterior Cables + Electrodes:
- 2 x Tens Leads (https://amzn.eu/d/7QgnzR2)
- RCA to 3.5mm cable (https://amzn.eu/d/73lRQMa)
- 12V 10A CLASS II Power supply (https://amzn.eu/d/iwG7B1n)
IT IS VITAL THIS IS CLASS II
- Conductive Rubber Loops (https://www.ebay.co.uk/itm/294897487467)
- Silicone Anal Electrode (https://www.lovehoney.co.uk/bondage/ele ... 62699.html)
- Electrogel (https://www.lovehoney.co.uk/lubes-essen ... /7749.html)


Tools (Reccomended, I had very few before the project and these were all I used with the exception of a few I'll list)
- Helping Hand for Soldering (https://amzn.eu/d/20RmVlf)
- Glue Gun (https://amzn.eu/d/8WDMRju)
- Soldering Kit (https://amzn.eu/d/7j8mMw5)
- Multimeter (https://amzn.eu/d/c0fQcyp)


I built it using this schematic

Spoiler: show

And with no previous knowledge of how to solder, but it wasn't hard to learn at all really

The only other tools I used were a razor blade for cleaning up my plastic, a lighter to melt the heatshrink and a screwdriver to do, y'know, screwing.

One thing I highly reccomend is testing your circuits throughout, wether it be with a multimeter or an aux speaker, it definately helped me along the way

I did hide the I/O of my amplifier inside the box, which probably isn't a popular move but hey ho.

Also, I know I purchased many unnecessary parts and could have just run the 3.5mm cable straight into the box, but I liked the idea of having external ports and seperate volume knobs for the 2 different audio channels so this was the way I did it

Finally, there are 2 extra switches in my plan as I couldnt find a switch which had 3 way connectors like in the picture, so as well as an on/off switch for the power circuit, there is also one for each individual audio channel


Pictures will be coming soon, and I hope this helps someone from the UK wanting to build one of these....
I know the lack of British information was one of the hurdles that stopped me doing it sooner so hopefully it won't be and issue in the future

[bobhill]

I'm starting on a build of lolo's v2 design and I can't find the 100v line transformer, but only this 70v/15w version. Is that a material difference?

When I get everything ordered, I'll post a US-based parts list for comments.

Thanks - BH

EDIT: I found the 70v/10w version on amazon here

[Gib Thopyn]

Pictures will be coming soon, and I hope this helps someone from the UK wanting to build one of these....
I know the lack of British information was one of the hurdles that stopped me doing it sooner so hopefully it won't be and issue in the future
[/quote]

Hello Harryc,

Thank you for your post, I stumbled across this thread after having tried some TENS pads on myself, which was a completely new experience and I wanted to know more about estim; I have joined Milovana because of this thread
lolo2's design has really taken my interest and I have read through this thread a number of times, having first thought I'd never be capable of making a DIY box, I'm now confident to give it a go, largely due to your post

It would be great for budding amateurs like me to see some photos of your design, which will help enormously with my build and confidence in completing my own. Any information regarding its functionality or reviews will also be appreciated

Estim will take teases to new heights of fun, thanks for all the information.

Does anyone use a RCD unit between the mains and 12V supply plug, would it improve safety.

[bobhill]

Still confused about the two switches? Anybody got a US link (amazon?) for each that would work?? Really appreciate it!

Looking at the last schematic posted, you can use a regular SPST switch for the tri-phase. They show a SPDT, which could be used and only hook up two poles (the center and one other).

The complex switch (3P3T) is trying to switch the input power and the outputs at the same time. Nothing wrong with that but I would say it's overkill. You just need a switch for the power, and a regular SPST will do for that.

https://www.amazon.com/MTS-101-Position ... B0799LBFNY

Thank you - this was really helpful for me! What is the point in switching the outputs using the 3P3T vs only switching the power with the SPST? It seems to add unnecessary complexity, so there must be some benefit.

[Mikeyh1972]

If you are still connected to the unit when you power off the amp, there is a “poke” that is a little uncomfortable for a second. This switch gets around that by disconnecting the electrodes simultaneously. I actually didn’t use it. I just turn the unit on before connecting the electrodes and disconnect the electrodes before powering down.

[bobhill]

If you are still connected to the unit when you power off the amp, there is a “poke” that is a little uncomfortable for a second. This switch gets around that by disconnecting the electrodes simultaneously. I actually didn’t use it. I just turn the unit on before connecting the electrodes and disconnect the electrodes before powering down.

Ahh, thank you!

[JakofClubs]

Thank you - this was really helpful for me! What is the point in switching the outputs using the 3P3T vs only switching the power with the SPST? It seems to add unnecessary complexity, so there must be some benefit.

If the circuit stored a lot of power, switching off the outputs might be a good idea to immediately cut the output. But the amps commonly used (class D amps) store very little power, so just killing the power cuts output immediately. Also, some amps "pop" a little when you turn them on or off.

[InfamousPlantain]

Hi Everyone!

Has anyone ever integrated @mantrid's high pass filter into the current v2 lolol design?

viewtopic.php?p=288013#p288013

I have some confusion because I don't think mantrid ever mentioned that he has the 4ohm resistor setup in between the amp and transformer like we do. Would it affect anything here?

In addition, do I put this high pass filter before or behind the 22ohm "smoothing" resistor in relation to the amp?
EDIT: Oh wait, he did say in here that it didn't matter: viewtopic.php?p=322776#p322776

My imagining is something like this currently....

thanks!

[JakofClubs]

Here's some pictures from my last build with a simplified schematic. It switches between three different high-pass filters.

schematic.png (28.47 KiB) Viewed 4562 times

Spoiler: show

joc_stim2_s.jpg (687.67 KiB) Viewed 3872 times

IMG_20221123_124440630_HDR.jpg (243.71 KiB) Viewed 4562 times

IMG_20221123_123400074_HDR.jpg (384.83 KiB) Viewed 4562 times

IMG_20221123_124510929_HDR.jpg (251.06 KiB) Viewed 4562 times

IMG_20221123_124529892_HDR.jpg (241.2 KiB) Viewed 4562 times

This build feels really good, but I'm not sure if it's the smoothing resistor and high-pass filter (which were good improvements), or that I used a better transformer. Quam TCH-70. It's supposed to be a "high fidelity" part. Not sure if it's that or just a better turn ratio (primary to secondary turn ratio).

It uses an "on-on-on" DPDT switch to switch between three high-pass filter capacitor values. 100up, 220uv and 330uf.
The different capacitor values change the cutoff frequency and feel a bit different. I did this to see what capacitor feels best, but it depends on the track which feel best.

[InfamousPlantain]

Hey, this is great! Thanks so much. It will take me a little to digest this. You seemed to have dropped off the 10ohm resistor part of the high pass filter spec ... unless you're relying on our existing 3.9ohm one to do the job.

Or

I could have grossly misunderstood the purposes of each resistor and that setting it up the way I did would probably end up negating something...

[JakofClubs]

Hey, this is great! Thanks so much. It will take me a little to digest this. You seemed to have dropped off the 10ohm resistor part of the high pass filter spec ... unless you're relying on our existing 3.9ohm one to do the job.

Or

I could have grossly misunderstood the purposes of each resistor and that setting it up the way I did would probably end up negating something...

I'm pretty sure when you add Mantrid's protection circuit, it takes the place of one of the resistors.

They say the best way to get the right answer on the internet is to post the wrong answer, I assume someone will chime in and correct me

[bobhill]

Hello all!

I'm continuing work on assembling my box, using lolo's V2 design. I couldn't get the 100v/10w transformer and got the Parts-Express 70v/10w used on other designs (330-040). I'm wondering about the transformer connections. Some use the 8 ohm and 0.62v leads and others, such as this, use 4 ohms and larger voltage - 10 volts on this one. Those are pretty large disparities, so any advice is appreciated. I've read these threads many times and an answer using technical electrical engineering discussion is beyond my knowledge.

Along those lines, I haven't received the 3.9 ohm resistor yet. Is the unit usable without that until those parts arrive?

Thanks - BH