Delays in parallel/series

[jghfslk]

Hello everyone

I am hoping to put two delays in one box and have the option to switch between having them in series or parallel.  I was planning on using this diagram:   http://www.rhythmanddetonation.com/wp-content/uploads/2011/01/SERIES-PARALLEL.jpg

I have connected two existing delays I have boxed (deprofundis and echo dream) in parallel with alligator clips and have them working but the levels change when I turn one on or off.  When one delay is on and the other is off, the delay that is on gets loud and feeds back quickly, especially the deprofundis (even with the feedback at zero I get more than one repeat).  When both delays are on, they seem to be functioning close to normal.

Any ideas what would cause this?  Would I need some buffers in the circuit somewhere?  I have built a splitter/mixer and have used that to have delays in parallel, but since I have an enclosure that I can use and have the option to switch between series and parallel with a switch, I would like to try it this way as well.

Thanks!

[jghfslk]

I built a splitter:   http://tagboardeffects.blogspot.com/2014/08/amz-2-channel-splitter.html
and a blend:   http://tagboardeffects.blogspot.com/2012/02/split-n-blend.html
and hooked up my delays to them.  The delays are working with the blend pot to either side, but when set in the middle there is a huge volume drop. Even when one or both delays are bypassed I have the volume drop.  I am assuming this is a phase issue.  Does the splitter reverse the polarity of one of the outputs and I just need to incorporate a phase switch?  Also would it still be possible to run the delays in either series or parallel with this setup?

Any help is appreciated!