I had to withstand the sovtek 6922, save yourself and get rid of them immediately they are wretched. In factit was by far the worst of about twenty or so I eventually tried. The sound you want and what the tubes are doing in their position are critical factors. Of course your budget counts as well.
I found that the white lable Amperex and you can pick these up as instrument pulls Texas instruments used them have a pleasant sound clean and neutral. If you can find pulls labled as the instrument makers tube they are an incredible bargain. I will say that most NOS tubes from reliable source, not the spent microphonic rejects I am finding on ebay these days (although for 5 bucks for an amperex pull is worth the gamble.) are generally speaking a better sounding tube from anywhere but China and Russia Whatever you choose even Ei or JJ,I like their products as a rule . Get rid of the Sovteks -they are an insult to tubes everywhere and why big companies use the cheapest piece of..... to put in their expensive gear is a complete mystery to me. If you have some money to spend and you know the tube slots citical to the sonics, take some time and look out for the Mullard 2493 not the 2492, these are truly special tubes extremely detailed not warm and soupy like a typical Mullard but robust and clean with great extension etc. It is a unique variant which actually sounds better, don't waste your money on silly things like pinched waist etc. Check out Tubemonger and see if he has any 2493 left.
