New to The Whole Tube Thing...

[EWBrown]

Yes, it can be done, with one simple modification, connect pins 1 and 8 together on each of the (6L6GC) sockets. The main difference between the two tube types is that the EL34 has cathode (only) on pin 8, and G3 on pin 1.

In the 6L6GC, the cathode is also pin 8, but it has the "beam forming electrodes" internally connected to the cathode. The EL34 is a power pentode, rather than a beam power tube, and the suppressor grid (G3) is brought out separately on pin 1.

If you decide to go back to 6L6GCs, this connection between pins 1 and 8 can be left in place.

Edit:

As stated further downstream, Make sure that pin 1 isn't used as a tie point or as a a ground (some 6L6s with metal on the base which is connected to pin 1 as a shield). Then connect 1 to 8 for each individual tube.

HTH


/ed B in NH

[erichayes]

Hi All,

A couple of caveats . . .

First, be sure pin 1 isn't already connected to ground (not uncommon) or being used as a tie point for other components (rare, but not unheard of). If it's grounded, break the connection before connecting to pin 8

Second, the EL34 has a different optimal bias point from the 6L6 so, depending on the biasing method used (fixed vs cathode), the sound might wind up being the same to worse than the 6L6's. You might have to do some tweaking, but at least you're in the right forum for that.

[sorenj07]

before you do so, are you sure it's the 6L6's themselves and not the circuit or other parts of the amp that sound fuzzy?

[dhuebert]

I get the impression that dave_thomas is talking about a guitar amp and that he is unsatisfied with the Fender 6L6 sound and is looking for the Marshall EL35 sound, in which case he should be posting in guitar amps. If the above is not the case then I don't know what he's talking about.

Don

[sorenj07]

speaking of circuitry, got a schematic for us? or maybe the amp model, so we can do the legwork on google and find one? i'm curious.

[TerrySmith]

Another thing to keep in mind is EL34's draw 1.5a on the filament, and 6L6's draw .9a.

Don't forget the other 6L6 variants such as KT66, 5881, 7581 etc.