is capacitance of a filter cap crucial?

[joshdfrazier]

i'm restoring a transformerless magnavox phonograph tube amp that uses a multi section can with values of 20, 40 and 40, (150v) all sharing a common return to the chassis.i'm having a hard time finding caps at these values, and when i do they are expensive. how important is uF when it comes to filter caps?

radiodaze.com sells a 160v multisection can with the values 33,47,47 for 8.25. what are the effects of increasing the capacitance? especially on these oddball amps with no power amplifiers?

[David Root]

You can go higher voltage if you need to. The cap values as well aren't written in stone and if the amp is more than 40 years old it certainly wouldn't hurt to use a bit higher values. This is an audio circuit so a bit tighter regulation is OK and might well improve performance.

The antique electronics Mallory type cap cans are relatively expensive, but will do the job nicely.

You might find what you need on ebay but old NOS electrolytics can be unreliable.

You could also try Steve at Apex Jr. He has stuff he doesn't list.

[Gaz]

Part of that restoration should be a proper isolation transformer and safety grounding. Those things are called widowmakers for a reason.

[pdf64]

Does it use a tube rectifier?
If so, that may define the max value of the reservoir cap.
Pete