6L6GB in a brownface Bandmaster?

[68goldtop]

Hi guys!

I could buy a pair of unused/matched Soviet 6L6GB for a very decent price, but I'm not sure if they fit my brown Bandmaster...
This amp may have come with 6L6GC or 5881 - and I've read that the 6L6GB´s were very close in specs to 5881´s. I just don't want to buy them if they don't fit the amp...

Any and all help is appreciated

cheers - 68.

 

[schmee]

The B is lower wattage. That could be good for some users. Are you able to bias your amp? Bias should always be checked with a tube swap, although we just stuck them in in the old days. But maybe that's why in some instances the amps sounded so different!
The 6L6GB has a lower voltage rating though at 350V and the BM is up at 450V or so.... But people have used 5881 or wgb tubes in those or similar amps a lot.. 350V is getting pretty low though....
So in theory, it may not be a good thing. Especially if your amp is a vintage BM I would not do it.

 

[68goldtop]

Hi schmee!

Thanks a lot!
Biasing is not a problem, as my tech works just a few blocks away...

... The 6L6GB has a lower voltage rating though at 350V and the BM is up at 450V or so.... But people have used 5881 or wgb tubes in those or similar amps a lot.. 350V is getting pretty low though....
So in theory, it may not be a good thing. Especially if your amp is a vintage BM I would not do it.

That's the kind of info I was looking for!
This set came up as an opportunity, but I'll just pass on these and get another set of back-up tubes down the road

cheers - 68.

 

[NTC]

A 6L6WGB is approximately equal to a 5881 (22W vs. 23W, respectively IIRC). A 6L6GB (no W) is 19W just like the original 6L6 and 6L6G.

 

[slider313]

I would stick with 6L6GC's or "real" 5881's. Both will handle the voltage but, be sure to observe the maxium dissipation rating for each.

 

[Pete Farrington]

Soviet 6L6GB for a very decent price

Seems likely to be 6P3S?
The soviet type used to sub for 5881 / 6L6GC are 6P3S-E.
Hence the very decent price.

Edit - if it seems weird that soviet valves are so close to western types, it’s not because they’re reverse engineered copies, but rather in 1937, they bought the technology, licensing, facility and training from RCA
See https://en.m.wikipedia.org/wiki/Russian_tube_designations

 

[Kesi on guitar]

Buy them

 

[Pete Farrington]

Buy them

Based on what?
That amp was designed around 6L6GC / 5881, ie the WGB, not the inferior GB.
If the 6P3S coped in a typical 6L6WGB / 5881 application, surely it would be advertised as such?
The fact it’s advertised as GB is telling.
If used in a WGB / GC application, there would be no comeback if they fail in short order.
I seem to recall that Groove Tube was selling 6P3S as strong 6V6, in the late 90s when decent current production 6V6 were unavailable.

 

[Kesi on guitar]

Buy them

sorry, I didn't read it right. I take it back