What would happen if you connected a 9V DC power source to a 12V device and vice versa- a 12V power wall wart to a device that only needs 9V to operate?
Here is a shelf in my rack (needs dusting, as I can see from a close up):
It has three devices, from left to right:
1)
Keces P8 low noise ultralinear power supply. Its function is to convert AC power from the
PS Audio P5 power plant (the unit on the lower shelf underneath) into DC power into two zones (two outputs in the back): one is 12V the other is 9V. The external power supply makes the lower end more fleshy and adds some weight to instruments and voices, although very little. The Keces powers the other two devices to its right:
2)
Mytek Brooklyn DAC+, which can be connected to a wall power socket with its own regular power cord, or if you have a higher end low noise external power supply like the Keces, the Mytek also has a 12V DC input. The power supply inside the Mytek DAC is excellent, but the Keces P8 unit to its left has a better transformer and more and better capacitors. The fact that the external power supply weighs almost double of the entire Mytek DAC+ with its own internal power supply in addition to the DAC/phono/headphone amp/preamp capabilities speaks volumes.
3)
SoTM tx-USBultra USB signal reclocker and conditioner (it accepts USB signal from the MediaServer and outputs a cleaner signal to the Mytek DAC+). This unit doesnt have an 120V AC power input and requires a 9V DC power like a regular wall wart, which is provided by the second zone in the Keces external power supply. The function of the USB signal reclocker/conditioner is to make the USB signal jitter free and cleaner, which can be actually heard.
Here is the trouble. A good 6 months ago I made a mistake. I sprayed a window cleaner on all of the devices' faceplates to clean them with a paper towel. None had a problem except the Keces. The cleaning liquid seeped inside the LCD display which tells you which zone outputs how much power (Volts and Amperes). So what it shows now is not legible (although you can make out the one voltage is a single digit (the 9V) and the other is two digits (the 12V), but you cannot be sure. For that reason I removed it from circulation 6 months ago.
Here is what it showed :
Here is what is supposed to show (someone elses unit with different voltages):
The back of the unit is of no help because it doesnt have any voltage markings, only a choice of zone outputs. Incidentally, each of the two zones can be switched to another fixed voltage. For example, a 12V output can be switched to a 15V in zone one and the 9V zone two output can be switched by the toggle switch next to it to a 12V DC output.
But that is irrelevant in this context.
I am very much afraid to burn the 9V SOTM with a 12V input or damage the Mytek DAC+ with a lower voltage or even the Keces itself, if any of this possible. Of course I am not going to go ahead and see for myself what happens. That is an expensive proposition. So I connected the power cables to the DC power outlets in the Keces and simply measured each cable with a tube biasing multi-meter. It clearly told me which is which so I didnt need to decipher the damaged LCD display. I know which zone is 9v and which is 12V. Marked them accordingly.
But still, what would happen if you connected a 9V to a 12V device and vice versa?
