Can I use 6L6 in my DR?

this issue has been discussed at great length on the forum several times and can be accessed using the forum search feature to get you to lots more info.

The short answer <g> is that it is possible, but not necessarily good for the amp nor markedly different in the sound achieved.

 

The real answer is the 6L6 draws twice as much heater current which may tax your power transformer.
Also the plate resistance is half as much as the 6V6 so your output impedance is different to the output transformer making it necessary to adjust the impedance if it is variable.

Also be aware that there are a few different kinds of 6L6 and 6V6 tubes with different suffixes that have different ratings.
The most common 6L6 is the 6L6GC.
There is also the 6L6G, 6L6GA, 6L6GT, 6L6WGA, etc all with different ratings.
Same with the 6V6, there are several different designations on those as well.

Best usually to stick with what the amp was designed for.

If you want a louder amp buy a Bassman or Super.

 

For several years I used a SFDR loaded with Russian 5881 tubes- the amp was actually owned by a bandmate who wasn't very technically oriented. He couldn't explain to me what if any adjustmets or changes had been made when his buddy had retubed the amp. However, I had no problems and it worked fine and sounded good.

 

Try the JJ 6V6S - it's a big bottle 6V6 with a 6L6 plate structure. The heater draw is 650mA compared to 980mA with the 5881. Oh and they sound great