JJ 6CA7 review

Discussion in 'Amps and Cabs' started by Miracle Man, Apr 20, 2015.

  1. Miracle Man

    Miracle Man Member

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    I just got a matched set of JJ 6CA7 tubes and thought I'd write a short review. These are the initial impressions after about an hour of playtime.

    The amp is a 81 JCM800 2204 50W with about 375V on the plates (low voltage version). I've used JJ EL34s (not E34L) for a long time in all of my amps so I will be comparing to those. I run the amp through a Marshall 4x12 with reissue G12-65 speakers. I used a double humbucker guitar with splitting options, but most of the review is based on the tone with the bridge bucker, as that's what I play through 80% of the time. EDIT: The amp is bone stock - bright caps and all!

    First, I played the amp with EL34s for a few minutes, to establish a reference tone. I like the JJ EL34 because it has nice present mids but a slightly darker top end witch matches great with the brightness of the JCM. The El34 is punchy but the low end is nothing to write home about.

    After a few minutes I loaded the amp with the 6CA7s and biased them up to about 55% of max dissipation. This might seem low but I bias all my Marshalls that way and really like how it sounds. Screen current is taken into account.

    I've heard that the 6CA7s are even darker then the EL34 (part of their appeal for me) so after a few minutes I was slightly disappointed as they seemed slightly brighter than the EL34s to me. But after some time, I realized that they are indeed smoother in the top end compared to the El34s, but they have more harmonic overtones, that make them seem brighter. The low end was bigger and not just like you upped the bass knob a few notches. It's deeper but at the same time it's never flubby and stays nice and tight. I don't know how well the bottom stays together at full throttle, but at about 5 on the master, they sounded wonderful. The bass was nice and crunchy, they compress in a very pleasing way. They breakup later than the EL34, although I could be mistaken, as it's been a while since I've cranked up the amp with EL34s.

    There's also this certain notch in the mids that actually makes the EL34s sound thicker. It isn't scooped (at all) - the 6CA7 sounds bigger with a wider frequency response, but for those thick mids, I'd still go with the EL34. The 6CA7 has a lot of air between the notes which makes it sound very open, but at the same time, the notch in the mids can make it sound slightly boxy. I could get this certain squawk higher up the fretboard when I was playing on the low strings. When playing distorted chords, the sound was very woody.

    One thing to note is the sound with a neck humbucker. The airiness makes it sound fluty and very smooth when playing leads, but the bottom end was simply too much with distorted chords.

    The tubes also sound amazing when I roll back the volume on the guitar. The extra harmonics really come into play here and the notch in the mids seems to really help with the clean-up. The tone was very touch sensitive and slightly glassy with the guitar volume backed off - I loved it!

    Also, I am hesitant to write this but here it goes anyway... the sound reminds me of early Van Halen. At this point I need to add that I have never been a super fan of VH. I totally respect EVH and like the music, but I rarely listen to VH at home and I've never been crazy about his tone. I know he supposedly used Sylvania 6CA7s back then, and some people say that the JJs don't really sound like those, but at the same time, I couldn't help myself from playing the bridge part of Panama. The mids and the harmonics just sounded so right.

    I'll probably swap the tubes around again later this week, but right now, I wouldn't say the 6CA7 is better than the EL34 or the other way around. They are just different (not world apart mind you). I will probably keep these in my 2204 which benefits from the deeper bass response, but I'll be keeping the EL34s in my 2203, which already sounds big.

    That's it for now...
     
    Last edited: Apr 22, 2015
  2. davebc

    davebc Member

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    Great review!
    Funny and timely because I literally just picked up a pair of jj6ca7's on Sat to try for giggles.
    but haven't had a chance to light them up.
    The reviews have been very positive.

    My only experience with JJ's was Gerald Weber used their 6l6's in my Kspot, and they sound
    great. He raved about their E34l's which Steve Carr's tube of choice in my Bloke.
    That tube absolutely kicks ass in the Bloke.

    But I hated the stock JJ34's and found them harmonically dead, bassy, and dull.
    That was after hearing them immediately after a nos pair of Mullards.
    I have yet to find any new production that comes even close those in harmonic complexity and detail.
    But it's a lot of fun looking.
     
    Last edited: Apr 20, 2015
  3. goddot

    goddot Supporting Member

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    I have the E34L's in my wizard amp and it sounds pretty good, punchy with good mids etc. I have a quad of these 6CA7's that I was going to try but I do not like attenuated high end so I'm worried after hearing your review.
    Another thing is that early van halen has that top glass high end that I like so if that is what you call blunted high end then I'm fine with that.
    I have one set of standard EL34's in one of my wizards and the tone sounds fine, similar to the E34L with a little more compression.
    I think its hit and miss with these tubes- you can get a few duds out there that sound lifeless and dull. So far so good for me..
     
  4. Blix

    Blix Supporting Member

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    Nothing "supposedly" about EVH using Sylvania 6CA7's, it's a fact. :)

    You should try the EH6CA7, they sound quite close to the Sylvanias according to Dave Friedman.
     
  5. Miracle Man

    Miracle Man Member

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    I understand that the JJ EL34 is not a universally loved tube. It is a bit dark and doesn't not work with every amp. But I like bright clear preamp tubes and bright guitar pickups. Since the 2204 is also quite bright, the darker JJs are a welcome addition. I certainly wouldn't put them in a Super Bass though... Since John Suhr, Dave Friedman and Bogner all used JJ EL34s at one point or another, they can't be that bad.

    At the same time many people stick their favourite bright power tubes in a 2203/2204 and then proceed to remove bright caps because it's too bright. I've found that darker tubes don't sacrifice the amps character like the cap snipping does so I choose to go that route and it seems to work for me.

    Do try the JJ 6CA7s yourself, they sound very lively with great harmonics. I never said the high end is blunted. The top is smooth, but I wouldn't say they're dark. They do sound glassy, especially with the guitar volume rolled back. One thing I forgot to add in the first post is that they are a bit stiffer then the EL34s, but I love the feel. I just hope these last...

    As I said, I'm not a big fan so I wouldn't know for sure, but if you say so, I believe you. I'm afraid I won't be trying the EHs any time soon, as I'm not really chasing that tone. I've had great luck with JJ EL34s in the past and just wanted to try some of their other offerings.
     
  6. Dr. Tweedbucket

    Dr. Tweedbucket Deluxe model available !!!11

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    Hmmm that sounds interesting! I may have to try some out. I have a 1959S that I'm running KT77s in right now. Good review.
     
  7. davebc

    davebc Member

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    Ok
    Finally had a chance to fire up the JJ6CA7's!
    Loaded them in my Victoria Regal 2 for ease.

    My first impression...this great tube, tight lows, tight punchy mids, nice sizzle in the highs,
    Very nice sustain.
    bold, focused, punchy!
    Much preferred over the JJ's straight 34.

    I'll have to try the JJ e34l's in the regal to get an apples to apples.
    But the e34l's sound absolutely phenomenal in my Carr Bloke.
    I can't ever imagine ever using anything else in that amp.
    They are seriously happening everywhere sonically.
     
  8. Dashface

    Dashface Member

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    I've been using 6CA7s for years in one of my Hiwatts, an 82 Custom 50. They sound amazing in that amp. They make it sound like a big Fender. Beautiful cleans and smooth overdrive.
     
  9. Miracle Man

    Miracle Man Member

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    Just a short update. I did some more testing and still agree with everything I wrote in the first post, except for one thing... I would say that between the JJ EL34 and JJ 6CA7 the latter is the better tube. It has a deeper bottom end which is what the 2204 needs in my opinion. Not that the El34 is thin, it's actually tighter and I would prefer it for fast aggressive metal or punk. But the broader frequency range of the 6CA7 just makes it sound bigger, especially with my PAF type pickups. The midrange of the EL34 is definitely denser, which makes it feel like it has more gain (even at bedroom volumes). But the main reason why the 6CA7 is the better tube IMHO is the top end. The 6CA7 sounds more alive and sparkly, while at the same time being smoother. The EL34 is darker but at the same time it can be shrill on the high notes.

    All in all, I'd say that the JJ 6CA7 is a lively, thick sounding tube, with a broader frequency range, airier mids and has less "sonic trash" compared to the El34. The difference between the two actually reminds me of a vintage Hiwatt (6CA7 - cleaner, airier) compared to a vintage Marshall (EL34 - denser midrange), on a much smaller scale of course.

    When the EL34s in my 2203 kick the bucket, 6CA7s will probably take their place.
     
  10. davebc

    davebc Member

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    Well I had some time tonight to put the jj6ca7 through the paces in my Victoria Regal2.

    All I can say is DAMN!!! This tube has far exceeded my wildest expectation.

    One of its dominating qualities is this instant prominent sustain. WOW

    The mids are rich, warm and punchy.

    But the highs have this complex singing sizzle and bite with great touch sensitivity.

    The tones I was getting with my Les Paul were stunning. I couldn't stop playing.

    These tubes will make your amp and guitar absolutely sing.

    I'm very blown away.
     
    Last edited: Apr 25, 2015
  11. WienerDog

    WienerDog Supporting Member

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    I use JJ 6CA7 tubes in my 50 watt plexi, and they sound great. I prefer them over EL34 tubes, even some NOS ones I have.
     
  12. BluntForceTrauma

    BluntForceTrauma Member

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    So has anyone tried the JJ EL34 II yet?
     
  13. tone?

    tone? Supporting Member

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    Cool review.
    Though , how is the JJEL34 dark??
    I find them to be quite bright. They have lots of high mids and treble and a bouncy tight bottom to me.

    I have winged Cs and those are much darker.

    Haven't tried 6Ca7's yet. Might have to.

    That voltage the is pretty low on your amp. I have a 77' 2204 and it's at 395v.
    Have you checked your wall voltage?
    Mine is right around 117v.
    Unless I have more stuff running and then it drops to around 115v.
    I do have a variac to compensate however.
    Higher voltage will affect the sound quite a bit as well.
    Your amp must be quite squishy at that voltage. Correct ?

    Nice review
     
  14. Miracle Man

    Miracle Man Member

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    I don't have as much experience with tubes as some other members here, but to me, the JJ EL34s are a bit dark compared to EH, Siemens and a quad of old Winged Cs I had. This has mostly to do with the treble, which I find smooth/dark, whatever you want to call it. I do agree with the high mid spike, which makes them sound dense as I described in a previous post. The 6CA7 has more top end sparkle but at the same time lacks that annoying high end, which can be unbearable with a bright amp like the 2203/2204.

    Regarding the voltage, the amp is in good shape and the wall voltage is ok as well (220V). It got as low as 365V with one set of EL34s (EH IIRC). My other amps also measure fine. Speaking of which, my 2203 has about 465V on the plates and I can't say that the low voltage 2204 sounds very squishy in comparison (which was a surprise). Even less so with the 6CA7s that are in the amp now. The biggest difference between the two amps (when they were both loaded with EL34s) was that the 50W had more high end harmonics and seemed to be more touch sensitive, but I'm not sure whether I should attribute that to the voltage difference, the 50W vs 100W power section or the Drake vs Dagnall thing. The 100W is punchier, fuller and warmer, despite the higher voltage.
     
  15. sickboy79

    sickboy79 Member

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    Cool review. I've never tried 6CA7s myself. I also like the JJ EL34 - much better than the E34L. I've tried KT77s in a few amps and like what I hear so far from them. I'll have to try these sometime.
     
  16. papersoul

    papersoul Member

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    Ahhh...I found an old post on the JJ 6CA7s. I just got a set for my PWE Event Horizon. I played around with bias and settled on about 36 to 37.

    I compared them to my JJ E34Ls and JJ EL34s. I also have JJ KT77S but haven't used those in years. I should have compared those as well.

    Been lookin at power tube's lately and did some research and after talking to various tube dealers, I was told that from bright to darkest, this is the order: KT77 - E34Ls - EL34II - EL34 - 6CA7.

    The one tube here I have to try is the EL34II. It is supposed to be like a fuller, smoother EL34 with a bigger bottom.

    Out of the ones I tried, I really like the 6CA7 tubes in my PWE at a bias of 37.
    Very big and full, plenty thick, fat low mids, full and deep 6L6 style low end and great clarity almost glassy in the highs, but not harsh. Single notes are big, fat, full and I may even say, round. Leads have a unique sound.

    By comparison I think my E34Ls sound more aggressive, a little boomy in the lows, but single notes are not as big as the 6CA7. The regular EL34s..I love too, and also seem really warm and a touch dark like the 6CA7s.

    I need more time with them all, when my EL34IIs arrive.
     
    Last edited: May 7, 2017
  17. bettset

    bettset Member

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    your review is good. this is what's cool......what isn't your taste is mine, so for a marshall type amp, i'd go with the 6ca7. it's not a problem changing a few tone settings on an amp, plus i use the guitar tone control anyways :munch
     
  18. Bandersnatch

    Bandersnatch Member

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    Ok ok I'm sold sheesh settle down!:p
     
  19. Miracle Man

    Miracle Man Member

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    OP here.

    That's a misquote if I ever read one. I never said that.

    Btw, after months of using these I went back to regular JJ EL34s in my amps (JCM800s), simply because they are a better fit for my rig. The JJ 6ca7s are still great though.
     
  20. Miracle Man

    Miracle Man Member

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    I just wouldn't want anyone to read your doctored quote and buy a quad of these based on it. You know, 'cause us gear whores ain't impulsive buyers at all...

    On the other hand, I'm glad you're amusing yourself. You must be a riot at office parties. Duuuuh.
     

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