Using non matched pair of output tubes

[artosalo]

Bias balance can be adjusted with -Ug1 as well as with Ug2, but it is not necessary to do with both and it is usually easier to do with -Ug1. Think for example UL-output stage.
Not very easy to make in such case.

 

[Kay Pirinha]

I'd guess that the majority of the tubes advertised as being matched are really not. Just something that every seller states. How exactly do you match rectifier tubes?

The claim of matched rectifier tubes obviously addresses those who imperturbably believe in the superiority of tube vs. SS rectification.
Best regards!

 

[wg_ski]

Usually people using tube rectifiers who are worried about power supply noise also use choke filtered supplies (even if it’s a cap input). The only time I could see rectifier balance being a problem is when you use a toroid power trafo, where you might get DC in the core and make the trafo itself loud and obnoxious (again, not as usual for tube rectifiers).

 

[brightcity]

Here's an interesting factoid, transistors and other solid state parts can be matched also. Consider that NPN, let's not consider PNP, devices can have Hfe range of over 200%. And that's for expensive HiFi transistors. Imagine stuffing a whole bunch in the same integrated circuit.

It would get tricky, but in my opinion the inbalance can be a good sound opposed to upping heater current

 

[TonyTecson]

The claim of matched rectifier tubes obviously addresses those who imperturbably believe in the superiority of tube vs. SS rectification.
Best regards!

Patrick Turner said it best....powersupplies

 

[6A3sUMMER]

Generally,

For a linear non-regulated B+ power supply, the stiffness of the supply is dependent on the following:

Power Transformer Primary DCR
Power Transformer Secondary DCR
Dynamic resistance of the rectifier tube, if there is any (otherwise the solid state rectifier essentially drops that out of the equation).
DCR of the choke, if any
DCR of any series resistors between filter caps
And . . . the capacitive reactance of the Last filter cap (the one that runs the output stage).

High DCRs, High Resistances, and low capacitance of the Last filter cap are all causes of UN-stiff B+.
In that case, the tube rectifiers dynamic resistance may be the least cause of UN-stiff B+.

And . . . guess what . . . all my tube amplifiers use solid state rectifiers, and Lots of uF in the cap that runs the output stage.

All my B+ caps to the output stage do not just filter 2X line frequency (120Hz); They also filter 20Hz current draw from the output stage.

 

[TonyTecson]

i avoid tube rectifiers in my power amps, i may use them in my preamps though.

 

[oga]

Bias balance can be adjusted with -Ug1 as well as with Ug2, but it is not necessary to do with both and it is usually easier to do with -Ug1. Think for example UL-output stage.
Not very easy to make in such case.

Yes, with UL this could be tricky.