Connecting a sub to a vintage integrated amp

I founds some on-line pics of your int amp and your proposed sub:

http://vintageaudio.dualpixel.com/photos/Integrated%20Amplifiers/Yamaha%20CA-2010%2003.jpg

http://www.hometheaterhifi.com/press/wp-content/uploads/2013/09/PSB8.jpg

From the pics, it looks like what you can do is set the coupler switch on the back of the Yamaha to "off", then you would need a set of "Y" RCA adapters to plug to the L/R preouts on the 2010 to the main inputs to 'recouple' the pre and amp sections, and then run RCA cables to PSB line level inputs.

From the pics, it looks like what you can do is set the coupler switch on the back of the Yamaha to "off", then you would need a set of "Y" RCA adapters to plug to the L/R preouts on the 2010 to the main inputs to 'recouple' the pre and amp sections, and then run RCA cables to PSB line level inputs.

This will work, however, it is not necessary. Look at the CA-2010 Owners Manual. The pre out is always active regardless of "coupler switch" position. Leave the "coupler switch" on, and connect pre out to the sub.