[quote name='pete.young' post='1194999' date='Apr 10 2011, 08:17 PM']Stevie, why do you think that? It's still fine above 'C' and is OK at lower volumes. I'd expect a transistor to either work or not.[/quote]
Oops, sorry... (hitting myself over the head) I didn't read carefully enough.
As far as replacement drivers are concerned, I wouldn't worry about modelling them, just get something close to the Spica specification. For a budget 10 with a ceramic magnet, one of the Fane Sovereigns would be good. If you want some real quality, look at the Celestion NTR10-2520E - at a price (although there are more expensive options around). LawrenceH has been trying that one out recently and maybe he'll catch this thread.
I wouldn't bother with the Deltalite personally - the Celestion is a much better driver at not much more money.