Originally Posted by penngray
Okay, I have the balanced MiniDSP.
I have always had a hard time measuring voltages...so what do I wire and what do I use to get the voltage? Do I just wire up my Multimeter to the output connections or is there more to this?
I also need to buy a 12V power supply and some phoenix to XLR cables. I think I can rip some of my XLR cables apart to make up a cable.
This may take a little while to get ready for measurements. Here's how I would go about it (others may have some better ways) and keep in mind a lot of these steps you need to do anyway to use it:
1. Get your instruction manual out.
2. Wire up your 12 volt supply.
3. Hook up the USB to your computer.
4. Install the software plugin you are going to use on the computer and get a little familar with it especially how to set input and output levels.
5. I assume you are going to connect the input to a single ended source (RCA).
6. Get a cable together with RCA on one end for the source and bare wires on the other end. Connect the bare end to the input terminal strip per the instruction manual - Unbalanced connection.
7. For now we wont wire the output to anything. I just hope that the output voltage wont be higher than normal with no load. If someone thinks it might be then we should go ahead and connect it to your amp.
8. I believe you are running balanced to your amp. If so when you do hook it up you will want a cable with an XLR on one end for your amp input and bare on the other end to connect to the Output terminal strip per instruction manual - balanced connection.
9. We will need a steady sine wave signal on the output of your source (Preamp?). Something around one Khz would be good.
10. You will need a meter that will read true RMS. Do you have one? Or a scope?
11. You also need to know what input sensitivity on the MiniDSP you are set for. Is it .9v or 2 volt?
12. I believe their software has an input level display. If so we want this to go to 100% as you turn up the signal on your preamp.
13. Assuming you do have single ended input from your source connect your meter across signal and ground on the input terminal strip. The meter should read either .9 or 2.0 volts depending on the MiniDSP's sensitivity setting.
14. We now know that we have 100% input to the MiniDSP.
15. On the MiniDSP software set the output for 100%.
16. Read the voltage on the output terminals, I believe from + to - since it's a balanced signal. (Someone please correct me if I'm wrong on this.) It should read 2 volts RMS if the factory is giving us the straight scoop.
17. It would be helpful for those of us planning to use single ended in and out if you would read the output voltage with the output connected per the instruction manual for unbalanced output. That is connect a jumper on the output terminal block from S to -. Now read the voltage across + and -. It should still be 2 volts if what the factory is saying is correct. This is the reading some of us are questioning.
Whew - sorry that got so long Penn. Hope it didn't scare you away. As I said before most of the steps you are going to need to do anyway to use it. Basically what we are doing here is to put a 100 % input signal to the DSP, confirming with a voltmeter that it is in fact 100%. We are then adjusting the mini DSP software to give 100% output, and finally reading the output voltage on a meter or scope.
If anyone finds errors or omissions in these instructions, or a simpler way to do some of it, please comment.