I've definitely considered Op amp outputs. However one show I played my DI from my amp (GK2001RB) which has a TL072 driving the balanced output and it didn't sound that great. I switched to my Radial JDI with the Jensen transformer and I couldn't believe the difference. I have a difficult time believing it was the amp that caused the sound quality to suffer (it was pre eq and it sounded great through my cab on stage). Perhaps I'll have to drop the coin on the transformer and try both. Driving the long cable run is concerning, too.