Tube Rectifier versus SS

[odourboy]

If I replace a tube rectifier (a 5Y3) with diodes, what sort of B+ voltage increase, can I expect (if any)?

Thanks!

[benoit]

If I replace a tube rectifier (a 5Y3) with diodes, what sort of B+ voltage increase, can I expect (if any)?

Thanks!

I could be wrong but I'm pretty sure a tube rectifier drops significantly more voltage (maybe like 30 or 40 volts) as compared to less than one volt per diode. If I'm not mistaken you'd see about that much additional voltage. Hopefully someone more experienced will jump in.

I think I read somewhere that someone makes a special circuit that plugs right into a tube socket to substitute diodes for a tube recto, but I don't remember who.

[Rattlecat]

I save tidbits I've gathered reading around on different amp sites. I have a word doc that I've saved with tube rectifier voltage drop estimates. Not as accurate as it could be I suppose, but my info says in the neighborhood of 50-60 volts for a 5y3.

[skyboltone]

If you know the load and the input ac volts you can look at the curves for the 5Y3 and get pretty close. I know in a two 6BQ5 build that the difference between a 5Y3 and a 5AR4 is negligible. 5U4s drop more in my experience. I would guestimicate that you'll gain 20-30 volts.

[statorvane]

Depends on what brand 5Y3 you are referring to. I believe the Sovtek offerings are far stiffer (less voltage drop) that the NOS types. So if you are replacing a Sovtek 5Y3 with diodes, the voltage rise won't be as much as it would be replacing NOS 5Y3s.

[tubetek]

These are approximations:
5Y3GT - 1.1x AC (Real NOS; Sovtek is closer to a GZ34)
5U4GB - 1.2x AC
5AR4/GZ34 - 1.3x AC
1N4007 - 1.4x AC
The thing is; each of these devices has different current ratings...Usually only an issue with 5Y3 current limit or 5U4 3 amp filament requirement.
MORE COFFEE!!
tubetek

[odourboy]

Thank you gentlemen!

[krash]

there are curves for this on the datasheet.

no need to guess.