Dual Rectifier Tubes

[zozoe]

Hi all, I'm looking at a few different old P.A. amps to possibly mod for guitar, and one or two have dual tube rectifiers, and I'm curious to know why, would if offer more sag, or more OD opportunity?
Thanks & be well!

[wpaulvogel]

Dual rectifier tubes offer twice the rectifier capacity for the power supply. They sag less and allow higher filter capacitor capacity for more stable current, voltage and filtering.

[xtian]

Dual rectifier tubes offer twice the rectifier capacity for the power supply. They sag less and allow higher filter capacitor capacity for more stable current, voltage and filtering.

If that's the "why", then WHY does Mesa have a SS/tube recto switch on their Dual Rectifier series? I though the point was the sag.

[Phil_S]

I think we need to know what rectifier tubes and what & how many power tubes.

[pdf64]

Dual rectifier tubes offer twice the rectifier capacity for the power supply. They sag less and allow higher filter capacitor capacity for more stable current, voltage and filtering.

If that's the "why", then WHY does Mesa have a SS/tube recto switch on their Dual Rectifier series? I though the point was the sag.

My guess is that the silicon / tube rectification switch allows the option of saggy or stiff characteristics at high power outputs, user selectable according to their preference.

[nworbetan]

Dual rectifier tubes offer twice the rectifier capacity for the power supply. They sag less and allow higher filter capacitor capacity for more stable current, voltage and filtering.

If that's the "why", then WHY does Mesa have a SS/tube recto switch on their Dual Rectifier series? I though the point was the sag.

Because of the current limits on rectifier tubes. One tube rectifier is good for a pair of output tubes, a pair of rectifiers for a quad of output tubes, and three rectifier tubes for a sextet of output tubes is just silly, but they do it anyway.

[wpaulvogel]

This topic isn’t about Mesa amps. It’s about old PA amps and if they are old enough, solid state rectifiers weren’t used. The purpose of the dual rectifier tubes in this example is for power supply stability.