@deone thanks for your response.
1. Yes, tried
2. XLR input from Zesto Leto preamp. I do not think Zesto is the issue, as the headphone output is working fine. Also both output tubes going out at the same time is rather unlikely
3. It is class D, but it gets warm when on. I have had these for years, they are never cold to the touch.
The one last thing i will do is change the xlr cables from Zesto to Mola Mola, but again two xlr cables going out at the same time just isn't likely.....what a mess.,