Here’s a rare example of a 70s Ampeg SVT that I had in the workshop recently.
The SVT has, rightly, gained the reputation of being one of the greatest bass amp ever made. Even today the SVT is the industry standard bass amp for live work.
Working on these amps is not for the faint-hearted, with an HT in region of 700 VDC.
Unusually this was a UK voltage version; most of the 70s SVTs I’ve seen have been US voltage, necessitating a (very large) mains step down transformer.
The massive transformers don’t help with the weight.
This amp needed a couple of the 6550 output valves changing. Fortunately I was able to match a couple of valves with the existing valves in the amp, avoiding the expense of a complete new set of 6.
The amp achieved well in excess of 300W on the bench.