Skeptical Tube Guys and One Frustrated Electric Guitarist
It's a pretty simple story. We all either play guitar or bass (and have tube amps for those instruments), are hooked on tube audio, or have a thing for vintage short-wave radios. These things all require vacuum tubes. Unfortunately, even when you buy new tubes, you never quite know what you're going to get. How do you confirm that your tubes are good? We agree that the device you'll install them in is the best test, but for most people (and us) that's not very practical. We got frustrated with not knowing with certainty the condition of our tubes, and we wanted to help our friends, too. That's how Western Glow started. It's a part-time thing, but serious.
Testing is Often the Best Option (but do it right).
One of us has a McIntosh MR66 AM-FM tuner. It's retro as hell and sounds great, even in mono. One catch: there are 18 tubes on the chassis and two on the outboard multiplexer. Let's say it's starting to make weird sounds. What do you do? Among the first things most competent service people will do is test the tubes. You just bought a Fender Super Reverb? We love those. Want to know if those old tubes are in good shape? Yep, you will need to test them. True, there are "only" nine tubes in that amp, but replacing them all would cost a minimum of $150. Testing them costs a fraction of that, and you'll know exactly where you stand. Another team member has a vintage, lightly used Scott 299B integrated amplifier with all-original tubes. Yikes, don't throw them out--those vintage Telefunkens are worth $300 easily if they test anywhere near good. Tubes competently tested on top-rate equipment are worth more at resale time. The buyer will have assurance and confidence, and that adds value.
Tube Testers--They're Not All Alike.
Believe us, all tube testers are not created equal. There are ethical, well-meaning people selling "tested" tubes, but many don't tell you much about how the tubes were tested, and some use drug store testers from back in the day that can do an OK job of a basic pass/fail for emissions, if they are calibrated, but that's it. These devices can't detect or quantify gas or noise with any accuracy. Most don't measure mutual conductance (Gm) in a valid way or at all. What's more, many vintage testers (even many Hickoks) beat up on 12AX7 and similar preamp tubes by applying high signal voltage during the test. First, do no harm. We have great, safe test equipment.
Avoid "Mysteries in a Box."
Most frustrating is that we've bought NOS tubes from big on-line tube sellers, and sometimes they have high gas and noise, or the triodes are unbalanced. The seller does not specify much of anything about the tube. They just say it is NOS or used, "tests strong," and that's about it. "Strong" is never defined, and seldom is anything said about gas or noise, leaving that for you to find out and then pay return postage to send back their "oversight." That's not honest. That's not how we work.
If you want to be confident, send your tubes to a service with top-notch equipment and folks who care about you and share your passion for music and tube equipment. That's us.