Thanks!
Here it goes.
Needed all the tubes so I got NOS matched pairs and quads. Replaced all wax caps with polypropylene caps of equal rating and higher voltage. Ecaps and cans have been replaced. Eveything was cleaned and solder joints were checked. The T2, bass output chnl 1, was sizzling and bubbling so I disconeccted it to see how the recap and new tubes would do. Everything sounded  great except minus the bass on chnl 1. Heavy hum even when the volume was down once it was nice and warm. Ordered a replacement transformer, NOS Merit A-2905 which I installed according to specs, blue and brown to plates and red to B+. The Merit however has a red blue and green, I connected green as if it were brown, unsure of colors since they have faded. Now I get great sound for about 2 minutes and the sound drops to a very low level and sounds tinny. I have rechecked all the tubes on my recapped mighty mite II, they all checked out. The unit has not had a chance to warm up enough with sound to tell about the hum balance since the new merit went in. I checked the sound dropping out on the phonograph, fm and am, and an auxillary in line from an ipod, same thing.
My tubes are all closely matched and before the new merit went in the hum balance dis nothing audible when adjusted.

Where dis you get the service manual for the R231?
Thanks!
Aaron