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How to tell if tubes are matched?

I am esagerly awaiting my first tube amp (not counting my bass guitar preamp). UPS says it is somewhere between Redmond Washington and Massachusetts (?). It uses matched tubes, and I'm wondering if I get them all jumbled up in the excite3ment to listen, is there any way to figure out which tubes are matched? Since I've never heard it before, I won't know if the sound has gone haywire, or if it's sounding as intended. It uses 4 matched pairs, so trying all the combinations until I found the one that sounds best would certainly induce thoughts of going solid state. Do they usually mark them somehow? Will biasing be affected? Will there be an obvious flaw in the sound (i.e no sound)?
honest1
sidssp
1,077 posts
 
If the output tubes are way off, you might have problem adjusting their bias. But in general, there is no way to tell if the two tubes are matched without running them through test equipment.
jea48
4,425 posts
 
Just a follow up. Some Amp manufactures will hand write the matched pair #s and socket# on the tubes with a marker.In any case they are marked in some fashion. This is because they have also set the bias voltage for the power tubes.

Jim
gardengirl
16 posts
 
If your serious get a tube tester from Ebay. We matched gain on 12AX7's for our Jolida hybrid and found it to be WELL worth while. If you have 6L6's or KT88's in the final - you will find a good used tube checker a valuable tool. We matched tubes for our older Conrad Johnson PremierII - also could hear the difference.
samujohn's avatar
samujohn
291 posts
 
I don't wish to be difficult, but getting a tube checker is not a good short range idea. The old (and I do mean old) tube checkers that are most often for sale, are only useful to separate the living from the dead (and many fail this criterion). Suggestions to the contrary are misinformed.

1. tube checkers must be calibrated to be of much use in matching
2. tube matching is not an easy or quick art to learn
3. power tube matching requires more than simple transconductance matching, it requires proper loading as well, a facility few, if any, commercial units have. A match of 5% under a realistic load is the usual standard.
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