Thanks for the tips. Yes I've looked at some of those devices. Might bite the bullet and order one soon.
I bought this one. It is very cheap, has 8 programs and 15 power steps for each. Sometimes steps 1-2 are enough.
You can easily find replacement pads on Wish, E-Bay or Amazon. You will need as these don't last long and start to sting when they don't stick properly. You can also find cock rings or anal plugs to attach. I haven't ordered any, I'm just pretending I bought a massager for my back.
The cable is connected with a mono 2.5mm jack (so only one channel). I bought an addapter mother 2.5mm to use with an audio as there are estim mp3s and software and funscrips on the web. In an illustration the electrod pairs were marked A and B. As an example I put A on penis tip and anus, B on bottom of the shaft and behind the testicles. This stimulates both the penis and the prostate.
EVERYONE PLEASE NOTE: this device and household audio devices are NOT ment for penile stimulation. Maybe the expensive ones are. So my advice again: don't use full power, don't use as a self torture device but a soft pleasureable stimulation. The voltage change is dangerous even it fools you it runs on 1.5V batteries.
Also anything electrical above the waist is dangerous. Nipple stimulation is made with both electrods on the same nipple, not one on each in order to avoid passing current through the heart, I've read sometimes it can have post effects, not noticed at the moment. Still I won't try that (or at least not on my left nipple). Please don't make me feel bad I started this topic.