difference in tubes

[coors]

Before I start to solder in the components could someone explain what the difference would be for the following
"6EM7 tubes may be substituted for the 6DN7 tubes if these 620 ohm 2 watt resistors are replaced by 1600 ohm 5 watt resistors"
What type of difference in sound would these tubes make and would it be worth to do this at first or wait and see how I like the way the stock sounds.
TIA
Sam

[Paul Joppa]

There have been some fairly recent threads on this - a search will probably turn up some more stuff (not all of it consistent!)

Basically, the 6DN7 sounds better to most of us. We included the 6EM7 as an option in case the supplies of 6DN7s dried up - which they have not done yet. It's a perfectly respectable tube, I don't mean to bash it, but I still prefer the 6DN7. I have a half dozen of them myself, probably a lifetime supply!

[tuffy_puppy]

hi paul,  do you mean to say a half dozen tubes or a half dozen pairs?  i love my sex 2.1 amp and will never be getting rid of it.  so i have hoarded up a half dozen pairs for the long haul.  but at almost 70 years of age that may not be as long as i would prefer.  if i read correctly that number of tubes will be adequate, right?  don pettit, long beach, washington

[Paul Joppa]

The current SEX amp came out in 2004, and I have the prototype that appears in the manual, with the original tubes. It has since been modified with the C4S and Magnequest iron, but the tubes are still the same.

They are used several hours, pretty much every day - the amp drives a pair of JBL L-36 speakers in our video den. I'd say home theater, but a 20" TV probably doesn't count even though we only watch DVDs now...

Main point, the tubes are still performing very well and there is no sign they need to be replaced yet. It's now been 8 years. I am 65 now, so figuring 10 years per pair my three pairs should last me until I am 95. Seems long enough to me. It's just possible I will switch to a Stereomour before then anyhow, and I have ten 2A3s lying around somewhere...  :^)

[keto]

I've just changed a S.E.X. amp from 6DN7 to 6EM7. To fit the new 5W resistor in I found it easier to use the lower connection at terminals 12 and 32. The sound is great, just like the 6DN7. Maybe when my ears break in a little more I'll be able to describe a difference :-)