5V4 recto in place of 5Y3?

[slidincharlie (Carlo P)]

May I safely use a 5V4 rectifier in place of a 5Y3 with no mods, as I've read in a book?
This swap was suggested to cure the HV spike stress in 5Y3-equipped amps without standby switch.
I'd like to use this trick in my Harmony H410 and Gibson GA18 amps.

[Enzo]

Those amps have made it this far with the 5Y3, why has it become a problem now? Are you actually experiencing "HV spike stress?"

[slidincharlie (Carlo P)]

No Enzo, I was just wondering if the absence of a standby switch is going to ruin those amps sooner or later, and if a 5V4 could limitate the initial (switch ON) stress on the tubes.

[Enzo]

I follow, but those smaller amps that have no standby switch have worked for 40 years. It seems odd at that point to start worrying if the design is faulty.

People hear about "cathode stripping" and then decide it MUST affect their amp. Guys operating 50kW transmitters should worry about such things, but really, the 6V6s in our little amps are not going to be stressed much by the brief instant where the recto warms up a hair faster than they do.

[slidincharlie (Carlo P)]

Ok Enzo.
I see your point.
Your advice is always wise, so I'll take it! :)

Carlo

[MWJB]

As Enzo says, there's little likelyhood of a 5V4 significantly increasing reliability in an amp designed to run a 5Y3, but for most people the change of rectifier may desirable for the increase in B+ voltage and tighter response when running a 5V4.

If you make the change keep an eye on voltages with respect to tube & cap ratings and on power tube plate dissipation.

[slidincharlie (Carlo P)]

Thanks MWJB.
Even if there is little advantage in terms of reliability, this could be a nice ground for experimenting with differences in sound.

[Enzo]

I do not wish to discourage experimentation in search of tone, please do and tell us about it. I was only addressing the reliability issue.

[slidincharlie (Carlo P)]

Ok.
Now the chase for a (possibly NOS) 5V4 tube at a good price is open! :)

[JimiRayBoneKing]

I dropped one of these in my 6L6 - 5E3 per Bruce's recommendation:
http://store.triodestore.com/5v4gtsov.html
It allows a huge increase in headroom at higher volume with a pair of crisp 6L6s. It still muds out at 12 but it's pretty clean up to about 9.

Good Luck

[slidincharlie (Carlo P)]

JRBK:
thanks for sharing your experience.
I still haven't had a chance to buy a 5V4.

[Jammin'John]

A 5v4 is a common sub in a tweed deluxe !
A little more headroom,louder,tighter bass,slow start up.

JJ

[Bob M.]

I like the 5V4 GA as it's not so humongeous. I run these in Champs/Vibro Champs all the time with great results. A great rectifier tube!

Bob M.

[Jammin'John]

I like the big coke bottle,dark coated on the inside one.
It looks just right in my tweed deluxe.

JJ