Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: floyd on March 08, 2013, 02:11:35 pm

Title: 6L6B ?
Post by: floyd on March 08, 2013, 02:11:35 pm
Just got my first "HOT ROD" Deluxe in for repair.. I wonder if Fender, ( or whoever they really are now ) ever thought about using shielded wire on the pre-amp grids ( noise ) ?! Anyway.. this came to me with Fender branded Groove Tubes 6L6B output tubes. I'm not familiar with this tube.. biasing and so-on. Same as 6L6GC ?
Title: Re: 6L6B ?
Post by: HotBluePlates on March 08, 2013, 03:14:57 pm
... this came to me with Fender branded Groove Tubes 6L6B output tubes. I'm not familiar with this tube..

From the days when tube vendors made up their own tube type numbers...

According to this chart (http://www.thetubestore.com/Groove-Tubes) (and I have no information to confirm/deny), the GT 6L6B is the same tube as the Sovtek 5881WXT. Sovtek's tube is a Russian output tube which is similar to a 25w or so version of the 6L6.

I'd assume 25w is the maximum dissipation, or watch closely for signs of redplating at near-max volume. I would not trust this tube to be capable of the 30w plate dissipation of a true 6L6GC.

Perhaps FYL, or someone else with knowledge of Russian tube types, will chime in with the real Russian type number and/or a Russian data sheet.
Title: Re: 6L6B ?
Post by: PRR on March 09, 2013, 12:32:37 am
In Russian military dress: 6Π3C-E
Title: Re: 6L6B ?
Post by: Jack1962 on March 13, 2013, 04:09:21 am
Groove Tubes are assembled in China
Title: Re: 6L6B ?
Post by: HotBluePlates on March 13, 2013, 08:14:39 am
In Russian military dress: 6Π3C-E

Then according to Frank's 6Π3C-E data sheet (http://www.mif.pg.gda.pl/homepages/frank/sheets/084/6/6P3S-E.pdf), this tube has a plate dissipation limit of 20.5w; don't know if the plate dissipation value was ever updated or if that is a soft limit like the Design Center system.

After painstaking entry into Google Translate, the heading for the section starting at the bottom of page 1 is "limit values ​​for electric modes operation".