I have problem with my Tenor150 - advices welcome

Beemer, you must be speaking with past horrors in mind; otherwise, I find it amusing that you would be making such comments about Tenor when some of the expensive gear you own come from a company (Levinson) that recently experienced similar problems. I know, because when Levinson's parent company was undergoing restructuring and the factory was moved, I was selling a Levinson gear of mine at that time. I had a hell of a time trying to confirm warranty and such. Their dealers around the world were of no help as some of them had gear that required repair service and some of them were waiting for their orders, placed months before, to arrive. Contact between the company and its dealers were essentially cut off. In this instance, here's a big company with arguably a long track record for excellent service and reliability experiencing the same problems as Tenor did.

Mqg30, this probably won't help if what Fmpnd suggested is true, but have you tried adjusting your powercords and cables so that they are as free from each other as much as possible? And how loud is this noice? This isn't a case of tube noice right?

Another thing to consider is that many respected and supposedly stable manufacturers of high-end audio equipment are pretty much the result of one man or woman's work and vision. To my knowledge, many of them do not have successors in place nor have they delegated much responsibility. For the manufacturers that have been in the business for a long time, their founder and company head may also be getting up there in age. Let's be honest here, many companies will not survive the loss of their leader and chief designer. In most instances, we are not only betting on one to three men's/women's continued passion and long-term profitability, but their health as well.

Then there's support beyond the warranty. Some companies will happily support their products forever, while others will be quite harsh when you're not the original owner and it is no longer under warranty.