filter cap values

[cminor9]

I am building a 6G3 right now, and I was able to get some 22mfd and 10mfd filter caps for a good price. I was considering using those instead of the 16mfd filter caps for the first three, and the 10mfd instead of the 8mfd for the last one.

I have read about how raising filter cap values will tighten the bass response. I have also read about how too high of values here will put undue stress on the rectifier. I don't know how much faith to put in those "facts" though, since I cannot explain why diff filter cap values would cause these things to happen.

Will this cause any effects to the tone or would it stress any components (like the rectifier, a GZ34)?

I am trying to think this one through, but I cannot think of what this would do other than provide a more even power supply (and thus a but less sag). Ideas?

[Enzo]

Typical caps in those days had tolerance ratings of +80/-20%, so a 16uf cap could have had as much as 28uf of capacitance and still be within spec. Moving from 16 and 8 to 22 and 10 is a threat to nothing. Feel free to use them.

Rectifier tubes have a maximum first filter cap size because an empty cap looks like a short circuit when the rectifier first starts to supply current. The larger the cap, the more initial charging current there is. SO 20-40uf or something is OK for a tube rectifier. 400uf would not be. How far over can you go? WHo knows? SOme guys routinely and successfully run much higher caps. In any case, you are not in that territory.

And as to the bass, a stiffer power supply will sag less on bass peaks, and so will reproduce them better. The desirability of this is a matter of taste.

Again, the changes you propose are minimal.

[cminor9]

Thanks, and good answer as always.

I didn't even think about the tolerance, but now that you mention it it's blindingly obvious. Much appreciated!