The 12AY7 and 6072
are the tube designations for a dual triode with medium gain that
shares the same pin-out configuration as the 12AX7 and its variants.
Pretty boring as a description goes. To put it differently, the 12AY7
can often replace a 12AX7 in your amplifier and give you a rich, warm
tone with lower gain than a 12AX7. (View our gain comparison chart for similar compatible dual triode tubes).
12AY7 tubes are not 12AX7’s and have many different properties. They
draw more current than a 12AX7 as well as having different internal
capacitance between elements and a different plate dissipation. Because
of these differences, they sound different in a circuit designed for a
12AX7 tube. The 12AY7 tube could cause problems in related gain stages
by changing the operation of those other stages, but this is rarely an issue.
All things considered, the 12AY7 has what I would call a blues sound. Warm, rich, and smooth while still delivering a good strong signal. Let’s look at a few:
Full reviews of the 12AY7 tubes we tested (click to go to its review):
JJ Electronic 12AY7 - This JJ tube is built in the same design as their ECC83S tube but is very different in terms of tone and gain. It provides another option for those that want to drop front-end gain and still have warm sweet tone.
This tube has the classic 12AY7 tone. Nice and warm with a smooth breakup characteristic when pushed. This is a big part of that woolly tweed tone that many folks love. I am always curious how tubes compare to other tubes in the same family so I did some tests. Compared to a 12AX7, the EH 6072 has 84% of the gain and the JJ 12AY7 has 75% of the gain. It is only a 9% difference, but if you find your usual 12AY7 does not cut enough gain, then the JJ is what you want to try. While the volume is not drastically different, the character of the amp does change. You get warmer trebles and a spongier feel.
I am really liking the new JJ 12AY7 and happy to have another affordable alternative from JJ. The tube is very well built and has no issues with microphonics. It doesn’t have traditional looks but it does have traditional tone and an attractive price point.
Electro-Harmonix 12AY7EH / 6072 and Electro-Harmonix 12AY7-EH / 6072 Gold - The Electro-Harmonix brand is well established and produced in Russia. Compared to products from the USA, it has a smaller plate structure and a fatter glass envelope. The sound quality is very good and the price is excellent. Sonically the tone is all American, making it an affordable alternative to something from Westinghouse or Sylvania. Not as sensitive or bright as a Russian 12AX7, while providing smooth mids and ample bottom end. If you are experimenting with gain, this is the one you want. The only difference between the standard model and the gold, are the gold plated pins. If you have problems with corrosion, it would be worth a few extra dollars to go with the gold.
Westinghouse 12AY7 - The Westinghouse 12AY7 is a very nice NOS tube for a reasonable price. A tube similar to this would have been standard equipment in early 1950’s Fender amplifiers. The bottle is smaller than the Russian tubes and the plates are a bit bigger. They have a ribbed, gray plate that is crimped as opposed to the Russian welded plate. This 12AY7 tube has nice, heavy, micas to keep microphonics down and delivers great blues tone at all volumes. If you really want to give your vintage gear authentic tone, this is the most affordable way to do it.
JAN-GE 6072A Black-plate - General Electric is known for producing many of the best tubes ever made in the USA. The 5751 and 6550 tubes from G.E. are simply the best. This 6072A tube continues the tradition. This tube has plates that are 25% to 30% larger than the Electro-Harmonix and have unequaled build quality. The glass envelopes, mica wafers, and plate assemblies are all built with precision and well assembled. The plate coating is glossy black, making them easy to spot. I don’t know if it affects the tone, but it looks cool.
The JAN-GE 6072A tube has a great sound. I find it a bit brighter than the other 12AY7 tubes and it certainly has a bit more detail. This is probably due to the fact that it has the largest plates of all the 12AY7 tubes I usually see. There is an RCA variant with very large plates but it’s virtually extinct.
I love this tube in a Fender Super Reverb. Lots of gain to rock out with and a very smooth, compressed, overdrive. The GE 5751 is the only other tube that comes close to this 6072A. The books say the 6072A has far less gain, but in real world conditions it’s hard to worry about. This is definitely the best of these 3 offerings.