I did a repair on a Vox Pathfinder 15R last weekend where there was no reverb. Replacing the 4558DD fixed the problem. The op-amp out to the reverb unit was working but the op-amp input from the reverb had died.
This may be a common issue. Some of the other amps I've looked at use a 4560 op-amp pair instead of the 4558.
This may be a common issue. Some of the other amps I've looked at use a 4560 op-amp pair instead of the 4558.