I firmly believe the preamp is the heart and soul of a system. Everything goes through it and it drives your amp.
I had the opportunity to own a Zesto Leto preamp. It is a seriously good preamp. It elevated my system's performance like no other component. I sold it to fund a DHT preamp I am having built to match my amp. It was a great pre, I took a huge step back using my old preamp til my new one is ready. You really should try something of that calibre with your amp....