Switching between 2 amps , 1 set of speakers?

mrdecibel - all I have on the Sony amp is a Rec Out , no pre amp out , so I may be out of luck , no volume/eq control ....?

back of receiver : 
http://www.canuckaudiomart.com/details/152037-sony_strv7_receiver__rare__serviced/images/182077/

Tommy , coming out of the Sony record out will not give you any volume or tone adjustment into the Marantz, but will allow your Sony to be used as a tuner, and / or the ability to listen to anything else connected through the Sony. Your volume will be through the Marantz. If you want some tone adjustment, you would need an eq of some kind connected through the Marantz. I would not feel the Sony worthwhile driving the Tekton DI se directly, as long as you have the Marantz. Just my opinion. Enjoy ! MrD.

Hi Tommy,
Your problem can easily solve, find tube preamplifier ( ARC, CJ or Dynco Pas- ng) that have two output and multiple inpyt. you can connect your two Amplifier and play.additional info,all external unit like cd,turntable etc.you can connect in input in tube preamplifier.
 Enjoy

I use this and it works great.Single ended tho..no xlr
On Amazon
TC-7220 2-Way Amplifier Speaker Selector Switch Switcher Comparator Crossover Routerby TEC4.4 out of 5 stars    27 customer reviews | 14 answered questionsPrice:$119.99 Free Shipping for Prime MembersGet 

• Listen to amplifier A or B through one pair of speakers
• Listen to Speakers pair 1 or 2 from one of the 2 amplifiers
• Compatible with all types of amplifiers and loudspeakers
• Input / output through gold plated binding post to accept heavy duty speaker wires or speaker wire pins
• No external power required

Avoid switchers if at all possible. They are one of the cheapest ways to destroy sound quality.