I picked up a pair of NOS Telefunken EC881's and spent the day comparing tubes on the Stereomour. I thought I would start with the 12at7 as it is not too expensive to experiement with. have the stock tube, a JJ Electronics Gold Pin, and a the Telfunkens. The so called "NOS" tubes seem to have been used and likely broken in. The only tube that doesn't have more than 20 or 30 hours on it is the JJ.
I spent the better part of the day listening to tracks on the various tube. OK, not very scientific but I have done a lot of comparison listening and have a sort of method to my madness. I tried to listen to as many types of music as possible to make sure the changes were positive across genres. Although I heard subtle differences at first, after awhile the Telefunken emerged on top in every case. The stock tube sounds really good too.
Although Doc different tubes are really a kind of tone control, there were some real positives with the Telefunken that seem to go slightly beyond a change in tone.
So in order of preference (my preference
):
Telefunken Ecc81 - More space between instruments, increased clarity for cymbals, bells and anything percussive. Voices are especially good on the Telefunken, more forward and larger. This tube does sound more 3d to me on my system. I would not say this is necessarily a "warm" tube but it sonds more fluid without any sense of harshness.
stock tube (can't read what it is) - a lot of clarity but a bit harsher than telefunken, Still sounds very good.
JJ Gold Pin - worst of the bunch to my ears, loss of clarity, some percussive sounds kind of disappear compared to the other two, A bit harsh and two dimensional to my ears.
I would say the differences between the stock tube and the Telefunken are less than those between the JJ and the stock tube.
Really enjoying this amplifier.
drew.
