Low-cost (~$40-60) DIY Stereo E-stim for Audio Input (based on TroniC's MidiStim)

[edger477]

Also, is there any final verdict on the 10 ohm 10w parallel resistors?

The resistors look good, but I'd try first building it without 10 Ohm resistors. Your box will be more efficient, and almost all modern amps work just fine if load connected is more than 8 Ohms.

That parallel resistor just converts part of amp power into heat. For old amps it was mandatory since they wouldn't produce output on low volume if there is not 8 Ohms or less load connected (some required 4). I think all modern ones will work even with 32 Ohm headphones (of course with less power but the extra power does not go into transformers anyway, it goes into that resistor and gets turned into heat).

what AC adapter do I need then in volts and amps?

Which continent are you at? Something like this is fine if you can get it https://www.amazon.de/-/en/gp/product/B00NWH1FTS/

[Corndogville]

Also, is there any final verdict on the 10 ohm 10w parallel resistors?

The resistors look good, but I'd try first building it without 10 Ohm resistors. Your box will be more efficient, and almost all modern amps work just fine if load connected is more than 8 Ohms.

That parallel resistor just converts part of amp power into heat. For old amps it was mandatory since they wouldn't produce output on low volume if there is not 8 Ohms or less load connected (some required 4). I think all modern ones will work even with 32 Ohm headphones (of course with less power but the extra power does not go into transformers anyway, it goes into that resistor and gets turned into heat).

what AC adapter do I need then in volts and amps?

Which continent are you at? Something like this is fine if you can get it https://www.amazon.de/-/en/gp/product/B00NWH1FTS/

I'm in the USA and this is the amp I bought:

https://www.amazon.com/gp/product/B099F ... UTF8&psc=1

Also, being a universal power supply, it's still not confirming what I need as far as amps/watts. Please explain it like I'm 5.

I also have a whole basket full over AC adapters, so I may already have what I need, I just need to know what to look for on the sticker....as well as anything I need to look for, safety wise.

Edit: It's probably overkill, but I own this one already:

https://www.amazon.com/gp/product/B08BL ... =UTF8&th=1

I'd rather use a fixed supply though, so if you can tell me what numbers to look for, I probably have it.

[Electro]

You'll want it to be a 2 prong(no ground) double insulated(square within a square symbol) and agency listed(UL for example in the US, or similar depending on the country) for safety.

12v 4 amps is ideal
...but your 3 amp power supply would be fine if it reliably stays at 12 volts under load

[edger477]

The one you posted has the symbol... if it is real :)



So you can use that one.

[Corndogville]

You'll want it to be a 2 prong(no ground) double insulated(square within a square symbol) and agency listed(UL for example in the US, or similar depending on the country) for safety.

12v 4 amps is ideal
...but your 3 amp power supply would be fine if it reliably stays at 12 volts under load

Thanks guys! I just ordered this 12v 4a one, as it was listed as "Amazon's Choice", let's hope it's good, and safe!

https://www.amazon.com/COOLM-100-240V-A ... r=1-4&th=1

Man these transformers are HUGE!!! It's a bit scary. The ones in my Davey box were the size of my fingertip.

This is the right thing, right?

https://www.parts-express.com/70V-10W-L ... quantity=1

I have a feeling this is going to be unlike anything I've experienced before, and I wouldn't probably know the difference even with the parallel resistors (though I will leave them out as you wise folks recommended).

I'm using the outside wires on both sides of the transformer, right? (0.5 on the trode side and ??? on the amp side?)

I have an old Radio Shack project box that I will probably mount the stuff to. It has a choice of 2 lids, aluminum and plastic. I'm guessing I should try and mount everything to the aluminum lid? So it can act as a big heat sink? Anything I need to worry about in terms of isolation? I was considering heat shrink tubing the resistors over completely, so they couldn't touch the alum plate, but if that's overkill or a dumb idea, let me know. I'll be trying to wire it all up in a few hours, got company coming over, lol.

At least I can take it for a test run with the adapter I have on hand.

My plan is to use 2 mono jacks, so I can use the old 2B cables. If I want to do triphase (the only thing I know as that's what my D box is), is it ok to just clip both negative wires into an alligator clip with a single wire electrode on the other end, for the common?

[edger477]

I'm using the outside wires on both sides of the transformer, right? (0.5 on the trode side and ??? on the amp side?)

amp comes to the SEC C and 4 Ohms (black and white), and the electrodes come to PRI C and 70V-0.62W (black and purple). That should give you the best ratio. Pay attention that primary common is on other side.

is it ok to just clip both negative wires into an alligator clip with a single wire electrode on the other end, for the common

Yes

[Corndogville]

OK, so when we get to SEC C time (seewhatIdidthere?) it's this side?



Thanks!!!

[Corndogville]

I'm using the outside wires on both sides of the transformer, right? (0.5 on the trode side and ??? on the amp side?)

amp comes to the SEC C and 4 Ohms (black and white), and the electrodes come to PRI C and 70V-0.62W (black and purple). That should give you the best ratio. Pay attention that primary common is on other side.

is it ok to just clip both negative wires into an alligator clip with a single wire electrode on the other end, for the common

Yes

Again, so the black common that goes to the electrode is on the opposite side of all the other wires we're using? Just want to confirm so I don't fry something.

Also, is it safe to use nylon zip ties to secure the transformers, at least temporarily, or do they get hot enough to melt them? Sorry if that's a stupid question. I wanted to try a test layout before I go through the trouble of drilling holes and trying to line stuff up in the enclosure. Judging by my old box, I'm guessing they shouldn't get that hot.

What do I do about the extra wires from the transformer? Clip them at the source or no? (Edit: I'm clipping off the stripped end and double shrink tubing them, one smaller piece to cover the cut wire, and one longer piece (same diameter) to cover well over both ends. Then I'll twist tie them all together for each separate transformer)

Was hoping to try it out tonight (as in nowish, haha) if I can make sure I'm doing it right

[edger477]

Again, so the black common that goes to the electrode is on the opposite side of all the other wires we're using? Just want to confirm so I don't fry something.

That is how it looks like by the markings on the pictures.

Also, is it safe to use nylon zip ties to secure the transformers, at least temporarily, or do they get hot enough to melt them?

If transformer gets that hot then something is very wrong.

I'm clipping off the stripped end and double shrink tubing them, one smaller piece to cover the cut wire

On mine I did similar, I put shrink tubing down near transformer and then folded wire back into it, did that with each wire, and then one large shrink tubing for all of them.

[Corndogville]

Again, so the black common that goes to the electrode is on the opposite side of all the other wires we're using? Just want to confirm so I don't fry something.

That is how it looks like by the markings on the pictures.

Also, is it safe to use nylon zip ties to secure the transformers, at least temporarily, or do they get hot enough to melt them?

If transformer gets that hot then something is very wrong.

I'm clipping off the stripped end and double shrink tubing them, one smaller piece to cover the cut wire

On mine I did similar, I put shrink tubing down near transformer and then folded wire back into it, did that with each wire, and then one large shrink tubing for all of them.

Thanks for coming to the rescue again!

I don't want to fry my corndog!

[Corndogville]

Again, so the black common that goes to the electrode is on the opposite side of all the other wires we're using? Just want to confirm so I don't fry something.

That is how it looks like by the markings on the pictures.

Also, is it safe to use nylon zip ties to secure the transformers, at least temporarily, or do they get hot enough to melt them?

If transformer gets that hot then something is very wrong.

I'm clipping off the stripped end and double shrink tubing them, one smaller piece to cover the cut wire

On mine I did similar, I put shrink tubing down near transformer and then folded wire back into it, did that with each wire, and then one large shrink tubing for all of them.

OK, I finished the thing, I think. The output jacks are just hanging loose right now, but I shrink tubed all the solder connections, so hopefully nothing can touch anything when I test it. The amp board's currently held in place by the wires, lol. I used green and black for the power connector. Since most folks seem camera shy about their messy builds, I figured I'd take one for the team:

Ebox1.jpg (195.17 KiB) Viewed 4094 times

Ebox2.jpg (230.7 KiB) Viewed 4094 times

I shrink tubed the entire length of the legs of the amp side of the resistors, leaving just enough to go into the terminal block, and clamped them, leaving me plenty of stiff but flexible leg to help me do cable management with. I tagged the other ends down with hot glue, to keep the resistor touching the aluminum plate, as a heat sink, if that makes any sense. The resistors aren't exposed anywhere. The transformers and power jack are held down with zip ties. I tested the board with my on-hand AC adapter to make sure the power light lit. The fixed voltage adapter is coming sometime today, but I'm just gonna test the box with what I have on hand.

If I don't post back soon, I died.

[Corndogville]

If I don't post back soon, I died.

I only died in the Shakespearean sense! That thing is strong! It works really well. Only quirk I noticed is if you wiggle the plug in the stereo input jack, it'll give you a nasty shock! Simple solution is just don't do that (at all really, but) at least when a file is playing! LOL

Thanks again for the help folks! I can safely throw the old 2B and Davey Box in the garbage. Will keep the Tens 7000 cos sometimes it's fun to go old school.

I'll have to go back and revisit the teases and files that felt too weak to be useful before.

Now all I have to do is figure out how to drill the holes right to put the enclosure over it. The box part is plastic, and a bit thicker than the lid. I'll post a pic when I manage to get it all zipped up, but you get the idea. Hehe

[Corndogville]

I've noticed it seems a bit harsh, especially if you're not entirely into it and are trying to ease in. Even trying to run it at low volumes doesn't work...it just kinda goes from "this doesn't feel like anything" to "woah Nellie!"

Also, now I finally know what people are talking about when they refer to "hot spots", yikes.

Wondering if the parallel resistors would mellow it out a bit. I have run it at full, the 2nd time I tried it (meaning, I don't want to make it too weak either), but if I had done that last night when I wasn't entirely there, it would have just roasted my dick.

I don't know what changed, if anything.

I did notice the regular resistors get a bit warm to the touch, after it's run a while, but not hot.

[edger477]

Are your electrodes having same surface area? If not then smaller one often feels harsh, it is normal.

[Corndogville]

Are your electrodes having same surface area? If not then smaller one often feels harsh, it is normal.

Interesting, I was using 2 regular stick on electrodes (R - tailbone and common perineum) and a steel ring or silver solder ring (L) for glans. Left was what felt harsh, with either, but I only had hot spots with the steel ring (which isn't as fitted), probably because of varying erection status.

jgjyyg.jpg (125.38 KiB) Viewed 3931 times

I did order some small stickies, both strip style and small circles, so hopefully one or the other will balance it out.

I also have a candle snuffer glans trode I made that I'll have to look around for (basically like a bell with no clapper, which I put inside of a stretched balloon to hold it in place. It should cover a lot more surface area.