Rex_Rocker
Well-known member
For the last couple months, I've been rolling 12AX7's in my amps trying to find what best compliments their tone. I've tried to get ahold of anything I can, but since I'm in Mexico, it's been a bit more difficult than I wish it was. Either way, I read as many reviews as I could to make the most informed purchases possible. Lots of reviews have been conflicting, so I figured I'd make my own in hope it helps somebody.
So anyway, here are my thoughts on the tubes that I got to try:
JJ ECC83S. I hear somewhat average-ish highs leaning a bit towards being restrained in this tube, but I also hear a scooped upper-midrange, hence it's reputation for being dark. I also hear a somewhat restrained low-end that does not reach too low, which contributes to a tight feel. They've also got a warm, juicy, round core mid and low-mid emphasis. These tubes are squishy, compressed, and gainy.
I feel these tubes do best in gain stages in amps that are bright and boomy or dry-sounding.
JJ ECC803S. I feel these tubes have a very even EQ response with some emphasis on brigt, sparkling, open highs, which contrasts greatly with the more popular ECC83's. The low-end is more open and deeper, and there isn't quite as much emphasis on squishy low mids like it's short-plate counterpart. They've also got a long plate, so they can be prone to microphonics. The gain is average, I feel, and they're also very open-sounding, so they don't feel overly compressed.
I feel these would be great for slots dedicated to clean channels and/or phase inverter positions in dark-sounding amps.
Shuguang 12AX7B. Thish is the famous Chinese 9th Gen that so many companies rebrand (Ruby 12AX7AC5, Penta 12AX7B, etc.). I feel the emphasis on these is on the high-mids with the rest of the spectrum being relatively balanced. They've got strong gain, so they feel gritty, angry, and grindy. The low-end is somewhat deep, but still plenty tight.
These are overall my favorite AX7's. I feel they do well in pretty much all positions, but I tend to use them mostly in tone stack drivers, where they feel somewhat balanced and neutral with a hint of grit. I also really like them in gain stages, though, as their grindy character can give the edge that JJ ECC83's lack.
Shuguang 7025. Yet another commonly rebranded Chinese tube (Ruby 12AX7AC7, Gold Lion ECC83 Standard Pin, etc.). I feel these have got an emphasis on midrange without the scoop in the high-mids that JJ's have. They're also not as compressed, but have got somewhat strong gain to them. The lows are tight and not overly boomy, and the highs, while not emphatic, are not dark either.
I feel these are another good option on gain stages, as they distort tightly and cleanly. Not my favorite, but not bad either.
Sovtek 12AX7WC. I hear restrained top-end and high-mids in these. They've also got an emphasis on low-mids and a slightly flabby bottom-end. They're also slightly compressed-feeling, but they haven't got a particularly strong output.
Not a fan of these. Their gain isn't as strong as others, and they're dark and kinda dull.
Sovtek 12AX7LPS. Neutral high-end with slightly scooped upper mids ala JJ. These are smooth-sounding as well. These, however, have a very deep and round emphasis on bottom-end, and they are not compressed or squishy-feeling at all, so their feel is very open. They've got strong gain too.
These are very popular phase inverters, and I get why. They're very big and open-feeling and sounding, and they help smooth out a preamp that has been filled with Chinese glass and/or a poweramp with bright airy power tubes. Lots of people dig them early in the signal chain, but I can't say I'm one of them. To me, they're kinda boring with a flabby low-end within the first positions. Also, their long plate structure can be prone to microphony.
Electro Harmonix 12AX7EH. Extremely bright with a strong emphasis on highs and high mids. Scooped lower midrange gives them some clarity, but the bottom-end is deep and uncompressed. These have got solid gain, but they are not squishy-feeling. These can't handle cathode follower positions, I've read.
Another tube I don't dig. Way too bright for my taste or my amps, and the bottom-end I don't feel is particularly tight either. I guess they could have some use in clean channels or lower-gain edge of breakup sounds, but for me... nope.
Tung Sol 12AX7. Another member of a family of Russian tubes that also includes the EH. These have got a bright and open high-end as well, but the mids are more even. These have got slightly scooped lower mids too, but not as much as the EH. The high-mids are also not as grating as its EH cousin. These have got a very strong gain as well, but they don't feel overly compressed.
These seem very popular within the first positions, and I can see why. They're open-feeling and clear-sounding. I dig them, overall, but they're not my favorite. I feel they can be a bit too open-sounding for many fierce, scoopy, modern high-gainers, but that's JMO. In the right amp, they shine, though.
Mullard CV4004/12AX7. Another member of the EH family. These are way more balanced frequency-wise, though. They're still clear and open-sounding, but I feel these take yet another step in the same direction as the TS did compared to the EH. These are smooth, but not dull like the Sovtek WC's. I feel these are somewhat of a Tung Sol meets a Shuguang 7025.
These look very similar to the EH's, but, while I don't like EH's at all, I love these. These are particularly good within the first stages to smooth out and fatten up a gritty high-gainer.
I still really want to try the Svetlana 12AX7 and the Mullard 12AX7/ECC83.
So those are my thoughts on what I've tried. The amps I've tried them in have all been modern high-gainers, so take this FWIW. I rarely ever play clean, and it's even a bit more unusual for me to play crunchy Classic Rock-type of tones. Tubes react slightly different to different amps, but I feel they get to keep some traits when compared to each other in the same circuit. I hope it helps anyone who's curious about trying any of these tubes.
So anyway, here are my thoughts on the tubes that I got to try:
JJ ECC83S. I hear somewhat average-ish highs leaning a bit towards being restrained in this tube, but I also hear a scooped upper-midrange, hence it's reputation for being dark. I also hear a somewhat restrained low-end that does not reach too low, which contributes to a tight feel. They've also got a warm, juicy, round core mid and low-mid emphasis. These tubes are squishy, compressed, and gainy.
I feel these tubes do best in gain stages in amps that are bright and boomy or dry-sounding.
JJ ECC803S. I feel these tubes have a very even EQ response with some emphasis on brigt, sparkling, open highs, which contrasts greatly with the more popular ECC83's. The low-end is more open and deeper, and there isn't quite as much emphasis on squishy low mids like it's short-plate counterpart. They've also got a long plate, so they can be prone to microphonics. The gain is average, I feel, and they're also very open-sounding, so they don't feel overly compressed.
I feel these would be great for slots dedicated to clean channels and/or phase inverter positions in dark-sounding amps.
Shuguang 12AX7B. Thish is the famous Chinese 9th Gen that so many companies rebrand (Ruby 12AX7AC5, Penta 12AX7B, etc.). I feel the emphasis on these is on the high-mids with the rest of the spectrum being relatively balanced. They've got strong gain, so they feel gritty, angry, and grindy. The low-end is somewhat deep, but still plenty tight.
These are overall my favorite AX7's. I feel they do well in pretty much all positions, but I tend to use them mostly in tone stack drivers, where they feel somewhat balanced and neutral with a hint of grit. I also really like them in gain stages, though, as their grindy character can give the edge that JJ ECC83's lack.
Shuguang 7025. Yet another commonly rebranded Chinese tube (Ruby 12AX7AC7, Gold Lion ECC83 Standard Pin, etc.). I feel these have got an emphasis on midrange without the scoop in the high-mids that JJ's have. They're also not as compressed, but have got somewhat strong gain to them. The lows are tight and not overly boomy, and the highs, while not emphatic, are not dark either.
I feel these are another good option on gain stages, as they distort tightly and cleanly. Not my favorite, but not bad either.
Sovtek 12AX7WC. I hear restrained top-end and high-mids in these. They've also got an emphasis on low-mids and a slightly flabby bottom-end. They're also slightly compressed-feeling, but they haven't got a particularly strong output.
Not a fan of these. Their gain isn't as strong as others, and they're dark and kinda dull.
Sovtek 12AX7LPS. Neutral high-end with slightly scooped upper mids ala JJ. These are smooth-sounding as well. These, however, have a very deep and round emphasis on bottom-end, and they are not compressed or squishy-feeling at all, so their feel is very open. They've got strong gain too.
These are very popular phase inverters, and I get why. They're very big and open-feeling and sounding, and they help smooth out a preamp that has been filled with Chinese glass and/or a poweramp with bright airy power tubes. Lots of people dig them early in the signal chain, but I can't say I'm one of them. To me, they're kinda boring with a flabby low-end within the first positions. Also, their long plate structure can be prone to microphony.
Electro Harmonix 12AX7EH. Extremely bright with a strong emphasis on highs and high mids. Scooped lower midrange gives them some clarity, but the bottom-end is deep and uncompressed. These have got solid gain, but they are not squishy-feeling. These can't handle cathode follower positions, I've read.
Another tube I don't dig. Way too bright for my taste or my amps, and the bottom-end I don't feel is particularly tight either. I guess they could have some use in clean channels or lower-gain edge of breakup sounds, but for me... nope.
Tung Sol 12AX7. Another member of a family of Russian tubes that also includes the EH. These have got a bright and open high-end as well, but the mids are more even. These have got slightly scooped lower mids too, but not as much as the EH. The high-mids are also not as grating as its EH cousin. These have got a very strong gain as well, but they don't feel overly compressed.
These seem very popular within the first positions, and I can see why. They're open-feeling and clear-sounding. I dig them, overall, but they're not my favorite. I feel they can be a bit too open-sounding for many fierce, scoopy, modern high-gainers, but that's JMO. In the right amp, they shine, though.
Mullard CV4004/12AX7. Another member of the EH family. These are way more balanced frequency-wise, though. They're still clear and open-sounding, but I feel these take yet another step in the same direction as the TS did compared to the EH. These are smooth, but not dull like the Sovtek WC's. I feel these are somewhat of a Tung Sol meets a Shuguang 7025.
These look very similar to the EH's, but, while I don't like EH's at all, I love these. These are particularly good within the first stages to smooth out and fatten up a gritty high-gainer.
I still really want to try the Svetlana 12AX7 and the Mullard 12AX7/ECC83.
So those are my thoughts on what I've tried. The amps I've tried them in have all been modern high-gainers, so take this FWIW. I rarely ever play clean, and it's even a bit more unusual for me to play crunchy Classic Rock-type of tones. Tubes react slightly different to different amps, but I feel they get to keep some traits when compared to each other in the same circuit. I hope it helps anyone who's curious about trying any of these tubes.
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