I am fairly new to tube amplifier building. A year ago I decided I would like
to build an HF amplifier using one or two 4-1000 tubes. In the past year I
have picked up 5 used 4-1000 tubes. 3 out of the 5 tubes were "bad". A nearby
friend offered the use of his amp to check the tubes. 2 had nearly zero
emission and one lit up like a giant VR tube when voltage was applied. (I am
working on building a Hipot tester!) Luckily most of the sellers cheerfully
refunded my money when told what happened. I don't know if my experience was
unique but it would seem to indicate that there are an awful lot of "bad"
used 4-1000 tubes floating around out there. I wonder if any other builders
have had similar experiences? I know it is tempting to "save some money" on a
used tube but If I had to do it over again I would probably try and save
enough money to buy a certified new tube. For about the same cost though one
could buy a new 8877 at current prices. I would guess that for the most
watts-per-dollar a couple of new 3-500z's would give the most bang for the
buck? Thanks for any comments. Todd Roberts
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