bf pr w/ 40,20,20,20uf cap can

[scole]

will using a 40, 20,20,20 cap can cause the 5u4 rectfier to fail? that is with the 40uf in the first position, looking at the schematic, the one on the right hand side that goes to ground.

[tubeswell]

5U4G type rectifiers are rated to take 40uF reservoir

[scole]

so having the 40 at the firdt node is already too much?

[octal]

I believe the Princeton Reverb has a resistor (1k+?) between the first and second power supply nodes (instead of a choke.) The second node is the screen supply. The resistor between the nodes will limit the inrush current to the rest of the filter capacitor chain, so you should be able to get away with more capacitance. YMMV.

If you're worried, ou could always use the 20uf section of the cap as your first node and use the 40 uf for the screen node or, if you want to play it really safe, for the final preamp filtering. That would definitely be safe and is probably enough filtering for an amp in that power class.

[tubeswell]

so having the 40 at the firdt node is already too much?

No - 40uF is fine. (The reservoir cap is the 'first' filter cap)

[tubeswell]

5U4GB datasheet

Hi Scott

FYI - this might come in handy if you haven't found one anywhere

FWIW I have also found that the Sovtek 5U4G (coke bottle shape) is a direct plug in replacement for a 5U4GB. Unlike most other 5U4Gs, the Sovtek '5U4G' has a maximum output of 250 mA.