Mullard CV4024/12AT7These are in Royal Air Force boxes, made in Great Britain, and are WONDERFUL. Each tube wrapped with a cardboard inner liner and pin protector. This is the most popular and sought after 12AT7 ever.
Super popular for VTL, Manley, Atma-Sphere, and others. Why? They were made better. Compared to the earlier Mullard with the folded plate these consistently last longer, have a tighter triode balance, and are quieter. Just because they are not crazy expensive at the present moment don't let that fool you. Higher price does not always mean better quality when it comes to new old stock.tubes. It means rarer. And that means maybe they didn't make that many in the first place. This tube was standard issue to NATO forces around the world, and now that the Cold War is over we reap the benefits. But they will go up, just like the Mullard CV4004/12AX7 went up. So party on.
Platinum grade - The best of the best. Lowest noise and microphony with the tightest triode balance we have available. This is typically 10% or tighter, but may be higher depending on available stock.
Gold grade - Low noise and microphonics with a triode balance typically between 15% and 20%, but may be higher depending on available stock.
Driver/Buffer grade - Lowest noise but not the lowest in microphony. Triode balance will be similar to Gold grade.
This grade is only suitable for use in the driver stage of an amplifier, or the output/buffer stage of a DAC or CD Player.
If you have a preamp or phonostage, you need at least Gold grade