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Re: dynaco caps

Rajiv -

You can put two caps in series to increase the voltage rating. Many amps did this, look at the Heathkit WM series for example. I'd suggest a pair of resistors across the caps to balance the leakage current (something like 220K should work nicely) and remember that the ground of the "upper" cap will still be 200+ v above chassis so will need to be isolated.

I'd personally keep the cap before the choke to a pair of around 50uf caps in series (25uf total) as to not stress the 5AR4.

Depending on your local line voltage, you might also consider bucking the voltage down slightly. Given the relatively high B+ in the Mark III even a small increase in line voltage translates to a large increase in B+. The 525v cap was always marginal in the MarkIII - watch the B+ line as the amp powers up. It often spikes over 525v until the EL34's begin drawing full current.




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  • Re: dynaco caps - Gary Kaufman 03/30/0305:42:30 03/30/03 (0)


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