Commentary on guitar amp tubes:
Today, there are many more choices of tubes than we had even a few years ago but only 3 major factories still producing tubes. Some people have a favorite brand, others swear by NOS (new old stock). Still others say “a tube is a tube, just use the cheapest thing you can get.” Of course, there are as many opinions about tubes as there are tubes.
Here is my opinion:
1) The majority of NOS tubes are overpriced, often over $100 per tube. Some are very high quality while some are the left over stock that could not pass inspection. Fortunately, there are still a few NOS bargains available so we do use them in some cases. If you insist on only NOS tubes in your amp and you are willing to pay the premium price, please tell me before the repair or estimate is complete. I will use anything you want as long as there isn’t a reliability risk.
2) Chinese tubes are getting better but it’s important to buy brands that have been carefully tested. Ruby, Tube Amp Doctor and Mesa all do a good job of testing Chinese tubes before putting on their brand label.
3) Russian and Slovakian tubes must be chosen carefully. Since all the tube factories are better at building certain tube types and not so good at other types.
4) Groove Tubes - There is much confusion in the market place about the Groove Tubes brand. In short, very few GT tubes, if any are made by GT. They buy “off-the-shelf ” current-production tubes and test them. Those that pass the tests get the GT label and higher price tag. We also test all tubes that are used in amp repairs. In addition to standard testing, we actually listen to the tubes and reject them if there are any audio problems. In general, I can supply the same tube without the GT label for a lower price. For that reason, we don’t sell or recommend Groove Tubes.
I'm very particular about which tube I use in various amps and each choice is made based upon several factors relating to sound quality, reliability, voltage and current requirements, microphonics, hum, etc. When applicable, we will ask you about your tastes and playing style and choose tubes that best complement your playing while avoiding tubes that are known to have reliability problems.