Bias help 6l6 models

[joesatch]

Plate voltage is 495v. I currently have Fender branded 6L6WGC in the amp. I cannot find specs on these. Are they 30w tubes or 19w tubes? Fixed bias A/B amp (blackface). Since i dont know specs i cannot determine if the current i have 36.5ma is hot enough. Also, i have ordered https://www.guitarcenter.com/Groove-Tubes/Gold-Series-GT-6L6-S-Matched-Power-Tubes-Medium-4-7-GT-Rating-Duet-1274034469078.gc but will have the same dilemma as i cannot determine how many watts these tubes are. PLEASE HELP!

[PRR]

> Plate voltage is 495v.

What is the maximum plate voltage for the 19W 6L6es?

[acheld]

If I'm not mistaken, that tube is a Sovtek 5881 (I know some of the Fender branded tubes are -- whether this one in particular is . . .?).

This should be close:  https://frank.pocnet.net/sheets/127/5/5881.pdf

[joesatch]

These are the tubes in the amp.  Is 495v plate too much? If so what is my next course of action?

[dude]

5881/6L6WGC, at 495 plate voltage, 36.7 mA each tube is at 70% dissipation, you're on the money. That tube is about 20 watts. 495vdc all day long, you're fine.

[joesatch]

5881/6L6WGB, at 495 plate voltage, 36.7 mA each tube is at 70% dissipation, you're on the money. That tube is about 20 watts. 495vdc all day long, you're fine.

thanks well i went through the tube calculations using the voltage drop method (Robinette).  What about these tubes can the same current and voltage work for them?  Groove Tubes Gold Series GT-6L6-S Matched Power Tubes Medium (4-7 GT Rating) Duet

[dude]

What about these tubes can the same current and voltage work for them?  Groove Tubes Gold Series GT-6L6-S Matched Power Tubes Medium (4-7 GT Rating) Duet 

Not familiar with a 6L6"S", look up the tube data on that tube. I would assume they are about 25watts, if so you'd want about 42mA but remember as the bias goes up the plate voltage goes down. Most 6L6GC tubes are 25/30 watts, but the S, ?

[66Strat]

I think that the "S" refers to the country of origin, Slovakia. I saw this on the Guitar Center website. The only tube manufacturer in Slovakia is JJ. The only 6L6 types that I can find on the Eurotubes (JJ importer) website are a 5881 and a 6L6GC. This looks like the 6L6GC, but who knows? I seem to remember JJ having a plain Jane 6L6 a few years back. This could be what this tube is. If so, treat it like a 19 watt tube. If it were me, I would pass on the Groove tubes and buy form a dealer that provides the specifications for the tubes that they are selling.

[joesatch]

I think that the "S" refers to the country of origin, Slovakia. I saw this on the Guitar Center website. The only tube manufacturer in Slovakia is JJ. The only 6L6 types that I can find on the Eurotubes (JJ importer) website are a 5881 and a 6L6GC. This looks like the 6L6GC, but who knows? I seem to remember JJ having a plain Jane 6L6 a few years back. This could be what this tube is. If so, treat it like a 19 watt tube. If it were me, I would pass on the Groove tubes and buy form a dealer that provides the specifications for the tubes that they are selling.

I had a coupon and was able to get the pair for under $20. I believe these are re-branded JJ 6L6GC so not 19 watts..

[dude]

Here's a bias calculator to help you bias those 6L6"S" tubes. I guess you can consider them a 19 watt tube, like a 5881? Or maybe just a 6L6..? If they are made by JJ, as suggested here, maybe a 25 watt tube. But anyhow, if you bias them as a 25 watt tube look for red plating on the plates in the dark, if you see a red glow, usually a round red circle in the middle of the tube, lower the bias.


https://www.tedweber.com/bias-calc/