Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Yosser on May 10, 2026, 03:46:31 am
-
I'm considering adding backup diodes to the GZ34 rectifier. It already has 47R resistors on each anode, will these become redundant with this modification, or should they be retained as the winding resistance is low?
-
If the resistor are there is to be supposed that when the amp was planned it was considered the low HT winding resistance so, if now you add diodes, keep the resistors on place
Franco
-
If the resistor are there is to be supposed that when the amp was planned it was considered the low HT winding resistance so, if now you add diodes, keep the resistors on place
Franco
This is a full wave gz34 rectifier with a LC filter arrangement 10H /10uf PSU and the anode resistors on each GZ34 are 22R each, however the secondary winding resistances are 32R and 30.4R which seem very low for this application. Should I increase the resistance value?
I can't find what the total value should be for the GZ34 rectifier (winding + added resistance) from the tube data sheets for my PSU, does anybody know what that is?
-
... This is a full wave gz34 rectifier with a LC filter arrangement 10H /10uf ...
So there's no reservoir cap connected to lug 8 DC output of the GZ34 socket?
If so, choke input rectification is somewhat different to cap input, the peak currents are limited by the choke, so lower value effective resistance in series with the rectifier anodes can be tolerated.
-
... This is a full wave gz34 rectifier with a LC filter arrangement 10H /10uf ...
So there's no reservoir cap connected to lug 8 DC output of the GZ34 socket?
If so, choke input rectification is somewhat different to cap input, the peak currents are limited by the choke, so lower value effective resistance in series with the rectifier anodes can be tolerated.
There is a 10uf capacitor connected there (lug8 both rectifiers ) followed by the 10H choke then another 10uh capacitor
-
It's a cap input rectifier then, though a lower cap value than typical, eg the datasheet is based on 60uF, much harder on things.
If you keep to the datasheet limiting resistance value (ie for a 60uF reservoir), at 10uF you should be fine. https://frank.pocnet.net/sheets/030/g/GZ34.pdf
-
It's a cap input rectifier then, though a lower cap value than typical, eg the datasheet is based on 60uF, much harder on things.
If you keep to the datasheet limiting resistance value (ie for a 60uF reservoir), at 10uF you should be fine. https://frank.pocnet.net/sheets/030/g/GZ34.pdf
Could some explain the formula on the website link above Rt=Rs+n^2Rp with examples please? (that might be a bit of an ask though!)