No real quadro sources. Using a Pioneer QC-800 pre-amp with in front a Quad 405 power amp and JBL 4311b. In the rear Philips 544 MFB speakers. I would like the same as in front but those JBL speakers are a bit rare and expensive. So pseudo quadro here. I like the idea of a quadro pre-amp because you can choose your own power amplifiers, you only need 2 of them.