Joule Electra preamp and Aragon 4004 mkII

I had a Joule LA 150 mk II in my system for a summer while awaiting repair of my main system line stage. I seem to remember that there were jumpers inside the cabinet that could change the output impedance of the line stage, but without an owner's manual or some direction from an owner, I wouldn't try to advise you. I gather the company is no longer- there is one web page that collects some info on Joule equipment but I didn't see anything about this in the quick perusal I did. I'm confident an owner with a manual can help you.

I owned both of these pieces, but not at the same time.
The 4004 MkII is a very good value for the money and has held its value amazingly well.
The 4004 MkII has a low'ish input impedance of 22K ohms (similar to some Pass amps).
The LA-150 MkII has adjustable output impedance of either 400 or 1200 ohms.  Most believe a ratio (input/output impedance) of 20 or better is sufficient to prevent audible frequency roll-offs, and some say a ratio as low as 10 should be sufficient.  Your proposed combination should work fine together and you can experiment with the Joule's jumper to determine which output impedance sounds better.
One caveat, many manufacturers report the average output impedance or the value at a frequency of 1,000 Hz, while the highest value can occur at the lowest frequencies, particularly with preamps that use an output coupling capacitor.  Not sure about the Joule but in any case the 400 ohm setting should work fine for you.