RJH wrote:

My 20 year old Rose valve preamp has started making a 'whooshing' sound,
varies in intensity, with a steady rush of background hiss. Might it be
the valves? Everything lights up, and I've had the back off and all
looks in order.


** After 20 years, it is time you replaced all the valves.

I can find no details on the net about the unit other than it uses four small valves, possibly ECC83s or 12AX7s.

The noise you describe is a typical valve fault.


..... Phil