After a good ten years use this valve pre amp started developing a little crackling and rustling noise on some of the inputs. The cause is oxidisation on the rotary selectors. As you can see from the dismantled switch in the picture the contacts on the left are dull with oxidisation whereas the ones on the right are shiny and would provide a good contact. Unfortunately cleaning switches is not possible they must be replaced.
Once repaired the owner was pleased to report that the preamp sounded better than ever. Why? Well this is because of how important a good contact is in delivering the whole signal. Degradation of contacts over time is difficult to notice as our ears get used to it.
So great to hear a 15″ speaker again. This is driven by a 30 watt class A four valve EL84 power section in WEM’s seemingly dated combo. But oh boy does it pack a punch. Rather than 30 watts you would be forgiven for thinking 100 to 150 watts. Such is the trickery that we have become accustomed to.
It’s called a 45 Dominator but nobody seems to know why. Perhaps it was meant to put out 45 watts but that is going to be tricky with EL84. Maybe it was aimed at middle aged home musicians in their mid 40s.
Couple of things to point out about this amp that make it rather special. Features that would be welcomed on many of today’s amps.
First of all is the amp chassis cushioning system. The brackets holding the amp chassis have for rubber supports that cushion and absorb all vibrations from the mighty 15 inch Italian speaker. I would so like to see this feature added on to some of the Princeton clone amps and other small Fender combos.
The other thing that I really like is the preamp screening cans. Most amps have aluminium screening cans to minimise noise in a preamp stage. The problems with these things spring loaded cans is that they tend to resonate and rattle. here in WEM they have chosen to wrap the preamp tube with a spring loaded piece of steel. This simple innovation is truly a sign of the innovation that WEM was capable of.