I got an old Ibanez AD80 Analog Delay.

It came with an old 18V Ibanez-brand wallwart.

I measured the voltage with my meter and this stock Ibanez wallwart is producing close to 23 volts (rather than 18 I believe required).

How hot is TOO hot?

Before anyone changes the subject....YES, I do have other power sources capable of giving a nice controlled 18 volt.

I'm just asking about problems that could occur by running the pedal with too many volts....and approximately how high could the voltage go and still be responsible in a unit like this.

Any thoughts, opinions, warnings and sage technical advise welcome!

Depends on the voltage ratings of the components inside. Most likely to fail, IMO, are the electrolytic caps. Resistors and film caps can take a good bit of juice.
If you are concerned, buy a good 18v regulated supply.

Hi,
I also have an Ibanez ad-80. Would it be fine to use it with "powerclips" and a Voodoolab Pedal Power 2? What kind of cable do I need? (some kind of Y-cable?) Do I need to use two outputs for this pedal or can I use only one?
Stupid questions but I'd rather be sure about it than frying this baby.

The pedal will either take:

18 volts DC on the adapter jack, with a tip positive 1/8" (3.5mm) plug

or

2 x 9v batteries (battery clips)

So, if you want to power it with a PP2, you can either use two outputs with a series Y-cable (to get 18 volts), and then add a converter cable to turn the 2.1mm barrel plug into a 1/8" plug. If you order the Y-cable from Voodoo Lab, they should be able to fit it with the right plug, though, thus eliminating the need for the extra converter cable.

If you want to power it through the battery clips rather than the adapter jack, you will need two separate 9vDC sources. For the PP2, that means using two separate outputs, with a battery clip cable from each output.

/Andreas

Oh, and re the oe adapter giving more than the 18 volts it is supposed to - most likely, it isn't regulated (many of the adapters used in those days weren't). If so, the voltage will drop as soon as you put some load on the adapter (i.e. plug it into the AD-80). Try to measure the voltage when it is in use (across the terminals of the adapter jack, while the delay is running), and you should get a more reliable reading.

/Andreas