Ideal PT for SS-rectified 18w?

[yello]

I've done lots of searching on the forum, but haven't seen a clear list of ideal power transformer options when doing an 18w with solid state rectification.

What PT's are best to maintain proper voltage without having to resort to additional tricks/parts?

I see the Minimalist schematic suggests a Hammond 261m6 but I don't see them readily available.

[JMPGuitars]

I wouldn't worry about the PT. Just use some Zener diodes as shown in the Tremolo TMB docs. The PT doesn't just supply voltage, it affects the tone and feel of the amp too.

Thanks,
Josh

[yello]

I wouldn't worry about the PT. Just use some Zener diodes as shown in the Tremolo TMB docs. The PT doesn't just supply voltage, it affects the tone and feel of the amp too.

Thanks,
Josh

I don't mind experimenting with tone and feel. Are there not PT's that supply the right current but with lower voltage need to offset the SS rectifier efficiency? Like a 235-0-235 or so, instead of the typical 290-0-290?

It seems lots of the lower voltage PT's also supply less current, so what I'm looking for is suggestions on PT for 18w with SS rec, that supply enough HT current.

[yello]

Maybe I should explore the Antek Torroidal PT's for a SS rectified 18w Lite type amp, seems like several options available, like this 280v PT with a 260v tap:

https://www.antekinc.com/as-05t280-50va ... ansformer/

[Psychodog]

To bring this thread back out of hibernation, I’m also dealing with this since I’m converting a PA amp with a SS rectifier. In my case my transformer is unidentified, but the PA has the same tube complement as the 18 watt (3 12AX7 triodes and dual EL84 power tubes).

While searching I found this site, which helped a lot. You can plug your tubes in and it’ll tell you what size transformer you’ll need.

https://thesubjectmatter.com/calcptcurrent.html

I was able to determine that my PA amp has a 260-0-260 transformer, since the calculator estimates that transformer will deliver an estimated 355 volts to the first node with a SS rectifier, and I measured 356. I’m going to use a dropping resistor to get down to the appropriate range since it’s only around ten volts.

Using that calculator it also looks like a 250-0-250 would be the ideal transformer, since it would deliver around 342.5 volts at the first node with a SS rectifier.