Vintage Cokebottle 6V6G-Safe for 5E3?

[Cygnus X1]

I grabbed a couple of NOS Sylvania 6V6G's from an antique store last weekend.
5 bux each.

They tested good on the Hickok 6000A, (3450/3500).
I'm wondering if the old 6V6's would be safe to try out in the 5E3 Tweed Deluxe?

I tried each of them in my single ended lead-it only runs 360VDC on the plates. Sounded good and didn't run too hot.
I Don't recall exactly where I ended up
voltage-wise on the 5E3, but it is stock.

What say ye?
Plug 'em in and see if they melt?

[Structo]

Not sure but we know that Leo ran over spec on just about all his 6V6 amps I think you should be ok unless the tubes are weak.


I have a pair of 1958 silver top Sylvania 6V6GT's in my Hammond amp that seem to tolerate 322v fine.

[Cygnus X1]

Cool.
I put them in-they are a tight fit side to side though.
They nearly touch.

They sound pretty good so far!

[rfgordon]

Neil Young has been running 6L6s in his 5E3 for decades, but the run a fan to cool the transformers.

[Cygnus X1]

Neil Young has been running 6L6s in his 5E3 for decades, but the run a fan to cool the transformers.

Thanks.

???

To be polite, what does that have to do with old style 6V6's?
I'm aware of N. Young's misadventures with these great amps. To each his own.

Edit-ok, I think you're referring to the heat issue (fan).
I ran it for about three hours, not especially hot.
The physical location is a bit troubling for potential mechanical damage.
I suppose I could put a band of heat shrink around them just in case.

[tubeswell]

If they bias up similar to what other 6V6s do, they should be fine for the time being. I'd replace them when they starting making crackling/hissing/popping noises.

[Richie]

usually the G rated ones run much lower plate voltages. Probably look at the spec sheet for the brand,some may vary a bit..

I thnk about 315 plate and 225 screens. Most of the G rated tubes were used in old car radios.. Same for the 6L6G.. much lower plate and screen rating than a 6L6GC

[Alexo]

Check your plate dissipation - the ratings get a little vague (design center vs design max, etc) but the older cokebottle tubes tend to want a slightly lower max plate dissipation, and a stock 5E3 can run even 6V6GTA's at well over 100%!

[Structo]

I missed the G suffix.


One sheet shows 250v Class A, and 250v-300v Class AB.

http://www.mif.pg.gda.pl/homepages/fran ... 6/6V6G.gif

[rfgordon]

Cygnus,
Sorry for the mixup, I mis-read the thread as coke bottle 6L6s. I have a pair of those, and they are absolutely stellar sounding! Definitely ones to put in the secret, recording only stash.

[Cygnus X1]

Cygnus,
Sorry for the mixup, I mis-read the thread as coke bottle 6L6s. I have a pair of those, and they are absolutely stellar sounding! Definitely ones to put in the secret, recording only stash.

Good news-I have a total of about 12 hours on them-no adverse effect.
In other words, just broken in, and they do sound good.

I'm resisting the urge to rip it apart to double check plate voltages.
But, not real big heat issues, the amp seems "happy", so I will just leave well enough alone.

[Cygnus X1]

usually the G rated ones run much lower plate voltages. Probably look at the spec sheet for the brand,some may vary a bit..

I thnk about 315 plate and 225 screens. Most of the G rated tubes were used in old car radios.. Same for the 6L6G.. much lower plate and screen rating than a 6L6GC

Yes, that is exactly what I was concerned about.
Newb Q is...cathode bias=self bias, right?
That is why I was wondering WTF I had for plate voltage in the first place.

Long story short is this particular build is a plate stuck into a Sunn Alpha combo. A complete PITA to disassemble and get back into it to do measurements.
The only clue I can give is I built it bone stock to the Fender 5E3 schematic...which does not show the voltages.

[Zippy]

You don't have to open it if all you want to do is check plate voltages.

How do you think the tube sees the voltage?

[Cygnus X1]

Good point, Zippy.

Yikes I'm a dork sometimes.
Glad I have stunning good looks to make up for it.

Wait.
Oh, nevermind.