bending on mains?

[zoomtheline]

I have bent quite a few keyboards and toys now with mostly great results but now I want to try 2 drum machines I have. Roland R5 and Yamaha RX21... I know these are bendable as I have searched on here aswell as other sites and seen some demo's got a couple of print outs of possible bends (rx21)
Now the problem is How? is it possible to wire up a battery supply or is it a case of knowing what your touching while its plugged into the mains.
I have had a look inside both and can vaguely work out the parts I know I shouldn't touch  and what I could but I am not 100% and obviously don't want a buzz! I did try a battery config but not knowing much at all about electronics I wasn't able to get it to work or know whether its possible at all.
I think I just need a few pointers before I go kamakaze and prod around.

any help will be greatly appreciated.

Thanks

[Circuitbenders]

This has been discussed a few time on this forum, just do a search for 'mains power' or similar.

Unless something is very seriously wrong with your power supply, in which case theres no way your machine would be working anyway, then its very very unlikely that you'd ever get any kind of shock from a machine with an external PSU running at those kind of voltages. If there are any massive capacitors in a machine then you might have cause to be mildly concerned but there won't be in any drum machine with an external PSU that i've ever seen.

[zoomtheline]

oh ok, so it should be ok to tinker whilst plugged in?

i'll search mains power now, I stupidly didn't think of searching that although I did search again earlier and read that whole thread about bending a R8 with that S-CAT character.......... very odd!

Cheers

[Gordonjcp]

It's okay, if it's an external power supply.  If it's an internal power supply, not really.  If the mains goes into the back of the drum machine and not into something like a wall-wart power supply, then no.

[zoomtheline]

thanks very much guys.
if you want to delete this thread as its covering old ground then thats cool.
I'll let you know how I get on anyways!

[manufactured zero]

The only problem i've encountered with bending using the mains is at times some bends behave differently when you switch back to batteries. Usually drone/feedback types. Another hassle is noise. I bend a lot of kawasaki keyboards and add an APC to them. I also add a power socket to run them off of 4.5 - 6v. They work fine either way but most power packs i use cause the keyboard to hum to some degree. It's not really a problem with the kawasakis as they're made to be noise makers. Worth considering though if you're planning to add power points to things.

[Gordonjcp]

If you're getting mains hum, either there isn't a big enough smoothing capacitor in the power supply or it's not capable of delivering enough current.  Pick a power supply that produces the right voltage, and at least as much current as the device needs.  More current is fine.  More current is good, in fact.  Less current is not good.  Wrong voltage (by more than about 10%) is not good either.

[manufactured zero]

If you're getting mains hum, either there isn't a big enough smoothing capacitor in the power supply or it's not capable of delivering enough current.  Pick a power supply that produces the right voltage, and at least as much current as the device needs.  More current is fine.  More current is good, in fact.  Less current is not good.  Wrong voltage (by more than about 10%) is not good either.

Cheers. I'll experiment with the next one i work on and see if i can solve this problem.