Ultra Tiger with UU4 Rectifier + 3 valves...

[pwdrive]

From a marketing point of view keeping the same name for different models could make good sense, a bit like the TV world of the Ultra Bermuda etc.

Lawrence.

[ppppenguin]

Referring to this thread https://golbornevintageradio.co.uk/forum...p?tid=7360 and the discussion about changing designs, it's quite possible that for technical reasons or pressure from bean counters that a product could be changed during its production run. If (say) the valve rectifier started to look expensive compared to the special deal they might have got on metal rectifiers they might have made the change. Or if the valve rectifier heater was running the mains transformer a bit hot then a metal rect might have made sense. I'm sure there are plenty of other possible reasons.