5y3gt on 6.3 ac?

[cbass]

I have a custom kraft model 880.Its basicaly the same amp as a Gretsch 6152. http://www.webphix.com/schematic%20h...retsch6152.pdf
I restored and modded it a long time ago tweaked made the reverb useable and did some things to give it bit more balls.Pre internet,(at least for me)It was one of the first tube amps I worked on.It sounded pretty good but I moved on to higher wattage amps.And it sat unused for several years.
SO i got it out a while back and was shocked by the sound quality and how loud it was.Perfect for practice jams and such.
I opened it back up because i was getting a red stripe down the center of the 6v6gta.By my calculations it was disapating about 20+ watts!.Took care of that.
Heres the kicker I almost didn't catch it.The 5y3 was on the same 6.3vac tap as the rest of the tubes.
I wasn't aware you could do this.Best I can tell all the tubes are original so i guess its been hangin in ther for the past 40+ years.
Anyone ever seen something like this before?

[jmaf]

AFAIK the 5 in 5Y3 means it uses a 5 volts heater. I've never tried to feed 6.3V into 5* tubes, but I'm quite sure 30% more current in there would ruin it rather quickly.

Did you just visually inspect it or did you take a measurement there? Maybe there's some gimmick hiding in there somewhere and lowering the voltage closer to 5V?

[nosaj]

Looks like the transformer has a 6.3 tap and a tap for the rectifier that's center tapped for the provided schematic. Does your transformer have 2 6.3 v taps? You could drop the voltage with a resistor.

Give some pics please

[cbass]

Its definately running 6.3vac.Theres only one tap. best i can tell its the factory transformer.I 've played the amp quite a bit before i noticed.
I know that 5y3's are supposed to run on 5volts thats why I'm posting.
You probaly can't tell by the way i word things and type(severe dyslexic) but I know my ass from a whole in the ground when it comes to tube amps.
I'm gonna try to research the PT some more to make sure its original.

[cbass]

Is there a 6volt equvilent for a 5y3.I'd really rather not add a seperate filament transformer.

[greekie]

Is it on the same heater tap as the 6V6 tube?! That would be bad...

[jmaf]

You probaly can't tell by the way i word things and type(severe dyslexic) but I know my ass from a whole in the ground when it comes to tube amps.

Didn't mean to imply otherwise, sorry about that. It's just that even experienced folks sometimes overlook simple stuff, a "peer review" sometimes finds simple things.

[jmaf]

Is there a 6volt equvilent for a 5y3.I'd really rather not add a seperate filament transformer.

The good news is, you have options.

6-volt rectifier tube - diyAudio

[Bruce / Mission Amps]

Since the 5Y3 has a directly heated cathode... etc... I'd like to know how the circuit is keeping the high voltage B+, delivered from lug 8 on the 5Y3, off the other tube's filaments...??
Some trickery there or it is not what it appears to be....

[jmaf]

Since the 5Y3 has a directly heated cathode... etc... I'd like to know how the circuit is keeping the high voltage B+, delivered from lug 8 on the 5Y3, off the other tube's filaments...??
Some trickery there or it is not what it appears to be....

Hadn't thought of that.....if it's coming off the same secondary, indeed the entire HT is being applied to all the heaters.

[cbass]

Since the 5Y3 has a directly heated cathode... etc... I'd like to know how the circuit is keeping the high voltage B+, delivered from lug 8 on the 5Y3, off the other tube's filaments...??
Some trickery there or it is not what it appears to be....

Hmmm your right I need to look at it again.I've got it put back to gather to make some shop/bench room.Not been playing.But there was definately 6+ volts on the 5y3.

[cbass]

Didn't mean to imply otherwise, sorry about that. It's just that even experienced folks sometimes overlook simple stuff, a "peer review" sometimes finds simple things.

Didn't mean to come off bitchy.I'm just not good at comunicating and it makes me seem dumber than i really am.

[cbass]

Ok I don't know my ass from a hole in the ground.They used the unused pins on the rectifier for connections to the 6.3.How in the hell I didn't catch that I don't know.Guess i'm not as smart as I think I am.

[cminor9]

depending on what you want to do, those 6 volt recto tubes (ez81, for example) won't do the trick. They seem to have a pretty low current/voltage limit.

I want to turn a Hot Rod DeVille into a 5F6a and looked high and low for a recto with a 6v heater that would handle the current and voltage. No dice. I wonder if you could somehow rig up a zener to give you a steady 5v? Then it would be a matter of how much current you can get from that filament tap without killing your PT.

EDIT: just remembered you're trying to use a 5Y3. Yep, as Bruce mentioned...directly heated cathode.

[cbass]

depending on what you want to do, those 6 volt recto tubes (ez81, for example) won't do the trick. They seem to have a pretty low current/voltage limit.

I want to turn a Hot Rod DeVille into a 5F6a and looked high and low for a recto with a 6v heater that would handle the current and voltage. No dice. I wonder if you could somehow rig up a zener to give you a steady 5v? Then it would be a matter of how much current you can get from that filament tap without killing your PT.

EDIT: just remembered you're trying to use a 5Y3. Yep, as Bruce mentioned...directly heated cathode.

There was no problem with the amp just with my brain.Thanks to everyone that replied.Sorry for wasting everyones time.