I had a previous issue with a brand new DSL20HR, also out of the box, but according to my store guy...that one had severe issues and, in the end, it was sent back to Marshall as a verified faulty model. In all honesty, I did my research and read through forums that there were some considerable reliability issues with the DSL20HR series, especially early models, however, mine was December 2020 model and still was messed up. Quality control seems to be a real issue here. I understand that many times it is hit & miss (as with anything in life), especially for the price that you pay...but I think that new stuff must work from start and there is no negotiation with that. If my studio JCM 800 only had a problem with a single preamp tube, then I can live with that for sure. Let's hope it serves me well for the years to come. I replaced all three tubes with new JJ's ECC83 and hopefully that settles it. Sounds gorgeous for sure!