Marshall^® Bluesbreaker 1962

I was excited by the sound, but...

Today started a demo and I was surprised with a range of tones, that I can get from this emulation. But after a few hours of recording, I discover some parasitic undervoice, that is very audible and sounds like a fifth lower than a single note, I'm playing. That's why I can't buy it, it is a big problem. Please, fix it, and I buy this super amp. Thanks.