The first question is: What paper, and most important, what profile are you using. That printer driver does not come with profiles.
What driver settings are you using with regard to color.
What is in the Qimage profile box in the setup panel? Does it say OFF or Let printer driver handle  color?
Did you have profiles made? If not, we have to set the driver properly.
Fred

PS This is from Epson's suggestion page

As ICC profiles are ink. paper, printer related - this service involves sending a printed chart so we can make an ICC profile using your inks paper and printer it is not a download service. Once received we usually make the ICC profiles same day.

See attached images.
If you are set to the same, and Let driver manage color shows in Qimage profiles, you should be fine,  If it still is magenta, then we wait for Mike.
Fred

I stand corrected. That printer does come with profiles. I googled it and read one report that there were none.
Sorry,
Fred

There's an extra color conversion in there.  Saving as sRGB and then converting to Adobe RGB isn't going to expand your colors.  That's like leading 100 people into a room with 100 chairs and assigning them seats, then pushing the 4 walls outward to make the room bigger.  Everyone is still going to be sitting in their assigned seats within the area of the original small room so it's just going to look like a bunch of people cramped into a small area in a really big room.  When you save your TIFF from the raw, just save it in Adobe RGB to begin with.

Or better yet, just print the raw directly from Qimage (and refine the raw if needed).  Qimage will likely give you more accurate color from the raw than ACDSee anyway.  Why is ACDSee in the equation anyway; seems like an extra/unneeded step.

Mike

Regarding  the advice re color conversion, I have dug deeper into the ACDSee system that I am using.  (I did mention that I was largely ignorant of how the program works)!  I have used ACDSee for a couple of years, and found it a simple way to post process. However, my use of Qimage has now led me to a new understanding of what is happening in the background of ACDSee.  The program allows two methods of post processing DNG files, either 'Develop' or 'Edit'. I have been using the edit option.  After processing, this option does not allow changes to be saved as DNG, so I have saved them as Tif, which in turn allows them to be saved without a profile attached, or with an sRGB profile.  In my ignorant state, I saved them with the sRGB profile, and then converted them to RGB 1998 as a further step. Since my discussions on this forum, I have investigated the 'Develop' option, and found that it allows me to save my changes as DNG files with the RGB 1998 profile attached.  This is giving me a resulting file that prints well in ACDSee, and much better in Qimage. I no longer have the excessive magenta cast that caused my query in the first place, and now have a much greater understanding of what goes on behind the scenes. 
I am reluctant to use Qimage itself for my post production, as it lack some of the controls I find useful, such as Perspective Control, and  the Repair Tool options. Also, I find its ability to selectively adjust the various color channels by means of slider controls to be very intuitive.

My grateful thanks to you all for your assistance. I am equipped now, I believe, to print with much greater confidence, and greater expectations of success.