Tube rectifiers are the current rage. They do sound better, but the modern production does have issues. It seems Chinese rectifiers can handle high voltage, but not high current and the Russian production have the opposite issue.
NOS types were built significantly tougher and can handle far greater abuse compared to current production types, but are getting increasingly harder to source. Most tube rectifiers , by the book, can handle only about 20-40 uF after the rectifier, but some manufacturers like Quicksilver ran capacitors as large as 320 uF with little or no issues ( they ran GE 5AR4’s).
We, at ADL, employ a different technique. We combine a solid state diode with the tube rectifier in parallel. Voltages will rise due to the greater efficiency of the solid state diodes (we always employ the fast recovery types, with much shorter switching times). One would believe the use of solid state diodes with their nano second switching times would make the tube rectifiers obsolete or not needed, but experience and actual listening reveals that A tube rectifier still adds to the sonics. It gives greater midrange and upper frequency detail and the sense of air, and also adds to the dynamics.
If you attempt this on your own, bear in mind that the B+ voltages will rise by about 50 volts so the first stage capacitors must be able to handle the rise in voltages. This means dropping resisters must also compensate for the voltage rise .
The benefits are that with the SS rectifiers greater current flow is available and bass response is bettered. You can run as large a B+ caps as you can fit with no drawbacks. You can also pretty much run any rectifier tube available since the solid state diodes will handle the majority of the load. In addition, because of this, the rectifier tubes should pretty much last almost forever.
Victim of a Cereal Killer 