Rode NTK Tube Replacement – Telefunken E88CC / Mullard 6922 Gold Pin

There’s nothing like a decade-long Rode NTK Tube Replacement story…

In 2002 I was in the market for a reasonably priced tube microphone for my home studio.  My research led me to purchase the RODE NTK.  As it turned out, I never actually used it on a recording because the high end was too harsh and brittle for my ears.  If you scan the various pro-audio forums out there, you’ll find that this seems to be the general consensus with this particular mic.  At the time I did a great deal of research on how to improve the overall performance of the mic in order to make it usable in the studio.  Replacing the tube in the mic seemed to be high on the list of every happy Rode NTK owner.  So (not putting ALL of my faith in what I read in forums) I reached out to Darren Rose, Chief Engineer at Rode Microphones, to get more information regarding tube replacements.  You can read his response at the link below.  There’s a lot of technical information in his response if you’re interested. Rode NTK Tube Replacement Post back in 2004

Fast forward 8 years….

I still have the mic and I’ve still never used it on a recording.  I thought of selling it a few time to buy something else, but instead found myself searching for other options.  In doing so I managed to stumble upon my OWN (forgotten) forum post above from 2004 regarding RODE NTK tube replacement and thought I’d finally give it a shot.  (Better late than never I guess.)

I acquired two high-quality NOS tubes to use in the replacement exercise.  The value and availability of NOS tubes tends to fluctuate wildly with demand so check out current prices and what’s in stock at The Tube Depot link below. I would not advise buying NOS tubes on eBay. I’ve done it before and I will never do it again.

  • Mullard E88CC / 6922 Gold Pin (Holland) – left
  • Telefunken E88CC (Germany) – right

So the replacement task itself is pretty straight forward:

  • Start by removing the outer casing of the microphone.

  • Remove the 2 screws holding the plastic guard in place and then remove the guard.

  • Remove the stock tube using a gentle circular pulling motion

  • Replace the stock tube with the new tube using a gentle circular pushing motion.
  • Replace the plastic guard.

That’s it…like I said…it’s pretty simple.  Be sure to remember to replace the plastic guard.  I’ve read that not having those screws in place can cause some grounding problems which result in less than desirable microphonic issues.  Better safe than sorry…

RODE NTK Tube Replacement Results

I will post my thoughts on the results separately….there’s too much information to put into this post.  Just suffice to say that this was…without a doubt…one of the biggest improvements I’ve ever made in my studio…..ever.  It was not subtle.  If you’re skeptical (like I was) that a quality tube upgrade can significantly improve the sounds quality of the RODE NTK….don’t be.  For me…it was night and day.  Yes…the tubes I used here are expensive.  Yes…it’s worth it.  No…you won’t regret it.

Once the tube replacement is complete with either of these options you’ll get an idea of what this mic can really do.


    1. So what improvement did you find and what was the difference between the Mullard and the Telefunken?

      • Metako – First of all both tubes were a MASSIVE improvement over the stock tube. I find the stock tube in the NTK unusable….way too brittle for anything (vocals, acoustic guitar). With the Telefunken I thought there was more detail on the high end….and it was smoother. With the Telefunken there this this desirable sheen (some low order harmonic thing going on) to the overall sound that made it work better than the Mullard…especially on vocals. The Mullard is awesome in my A-Designs REDDI….for bass the Mullard wins for over the Telefunken. Keep in mind that when you get the new tube, you need to burn it in for at least 2 days. It sound good right out of the box, but after it’s burned in all of the microphonics settle down a bit and it prints better and more consistently.

        • What do you mean “burn it in for two days?”: leave the mic on for two days?

          • Dale Simmons says:

            Yes…leave the mic on for an extended period of time to burn it in….like a couple of days. Tubes do usually sound different (better) after they’ve been burned in. Many people will say 30-50 hours is the sweet spot for a premium tube, but that really depends on the tube. The high-end is usually a little more tame and natural sounding after a tube has some hours on it.

    2. Ah sorry, I just saw your link above. Is the harshness totally gone with the Telefunken? Can you describe the sound in a bit more detail?

    3. Thanks. Great to hear of your positive results. Your experiences seem to confirm the general opinion that Mullards have good bass but are dark sounding and that Telefunkens have excellent treble, though some say it is thin sounding. Has the bass been reduced compared to the std tube? I’ve just ordered a NOS Amperex 6922 PQ white label made in USA so it will be interesting to see how that compares with your findings.

      • The Telefunken is definitely not thin, but I can see why someone might think that when comparing to a Mullard. With the Mullard in the A Designs REDDI I have to lower the gain from where I normally keep it with stock tube to get my desired bass sound. If not it’s almost “too tubey”….think too warm and wooly (if that makes sense).

        If you haven’t already, you should also check out the Genalex Gold Lion 6922 (Gold Pin). This is a new high quality Russian made tube designed to replace the NOS tubes. I bought one to check it out and use as a reference against the NOS and it was surprisingly nice and more than held its own. Burn it in for a couple of days and you’ll notice a big difference. If I had an expensive (NOS) tube failure during a session I could easily complete it with a burned-in Gold Lion. It’s a no-brainer especially considering the price.

    4. Yes I’ve heard good things about the Gold Lion 12AX7s so good to hear their 6922s are good too.

    5. Hi there,

      I have an NTK and I am looking to upgrade the valve/tube.

      I contacted a company who supply new old stock valves in hope that there would be someone with in the company that would know about mics and recording. However, I recieved the reply I hoped I wouldn’t get, they basicly said they didn’t have a clue but heres a list of expensive valves.

      These are the valves they gave me;

      Mullard 6922

      Mullard CV4109

      Mullard E188CC 7308

      Siemens E88CC 6922

      Amperex Philips E88CC SQ 6922

      It’s impossible to decide which is the best with out trying them, but to do that would cost a fortune so… Are there any you think would be best, or would you recomend something different and what kind of sound would they produce.

      Thanks for your time, I look forward to your reply.

      All the best

      Joe Blanks

      • Joe,
        Of the valves you referenced I would be most interested in the Mullard 6922 and the Amperex Philips E88CC SQ 6922. Although I bet the Amperex Philips is bit more expensive than the Mullard, I doubt it would be a huge improvement over the Mullard. I used a Mullard 6922 and it was FAR better than the stock tube in my NTK. It was a different microphone after that….big improvement. To take that one step further…I tried the Telefunken E88CC in the NTK and it never left the mic. The Telefunken is magic on the high end for vocals…smooth and silky. The Mullard was great too, however it almost seemed too wooly in the NTK for me…the proximity effect was much greater with Mullard than with the Telefunken.

        My suggestion is to find a Telefunken E88CC. You won’t regret it. It’s in the ballpark with what you’ve listed from a cost perspective and it will blow you away. Put it in the mic, turn it on and leave it on for a full day (or more) to burn it in. It will sound even better after burn-in. Let me know what you decide to do…

        FYI…The Tube Depot has a new cache of Telefunken E88CC. I just bought a backup.


        • Joe,
          Also, since this is going into a microphone, I would also advise you to have them perform the “Low Noise and Microphonics Test” (it’s an option on the webpage when you purchase). It’s well worth the $4 to avoid the frustration of having to send back a noisy or gassy tube. This HAS happened to me before and it was a huge pain/delay to get a replacement.


    6. Dale mate,

      You’re a blummin’ legend.
      Thanks dude, I’ll get on that straight away!

      All the best


    7. Hi there, so i read this review and bought a telefunken tube off ebay lol no problems or noise thank god,but i did save quite a bit of money.Anyway i tried it out last night yes you’re right better high end, and good mid,and yes crispy high end ,and mid range when first using in the ntk,.Waited 24 hours still on and it seemed to have lowered its self now, really smooth high and mid and tone with out being so harsh like last night since trying it after an hour, wow what a difference from the stock tube,Going to leave on for one more day.Thanks for giving this review ,this really has helped me and my mike out ,i feel addicted to use it more and more.Chris.

      • Dale Simmons says:

        Thanks for the comment. I’m glad the post helped and that you’re getting good results from the mic now.

        I know what you mean about getting addicted to the mic with the new tube. I’m using mine all the time now (vocals and acoustic guitar features). I love the high end sheen it puts on my vocal tracks (although the BAE 1073 MPF has something to do with that as well). It just sounds…expensive…for lack of a better word. No insult to RODE meant here, but I never thought I’d say that about the NTK. Some people think Telefunken tubes are too expensive. What’s expensive is a $530 tube mic that sits in its case because it’s too bright to use.


    8. Hi again ,ya your welcome dale,yes the second 24 hours i don’t know if they made a difference really other than calming down the tube some more,but one thing i noticed is if i really scream in the mike now, it doesn’t distort like before?. The thing is i never did the burn in thing with the original tube until i started to get this info from you guys online, even my amp i never did that.But I’m always leaning new things lol .As for the price i paid 120.00 new on ebay, some guy in Taiwan had a crap load of them so total was around 150.00 with shipping, so unless a tube is going to cost me 500.00, then to get the best sound is worth paying 150.00 lol for me anyway. I mean after all its just money, getting good sound for a sort music life
      is priceless if you know what i mean. Look at Eddie van halen ,he’s been chasing to get good tone for like 40 years,if i can recall there’s been a few times in life where i was like this is the shit!! ,and that’s hard to come bye in this short life .

      • Dale Simmons says:

        Well said. Talk about bang for the buck! This was hands down the biggest improvement I’ve ever made in my studio for $150.

    9. Matthew Coull says:

      Thanks Dale!

      My NTK sat for YEARS in the case, never liked the top end. Just changed for the $45 Golden Lion and WOW! It’s a new mic! (The Telefunken was just too expensive at the tube depot)

      I’ll certainly watch for a deal on a Telefunken, but I’m already way happier with my NTK! Thanks again for the post!


      • Dale Simmons says:

        Sorry for the delayed response….I’ve been out of the country.

        I was in the same boat as you. I wasn’t sure what to do with the mic before I upgraded the tube. It was just too bright for me on every source I tried it on…

        I own and use Gold Lion tubes as well (including a taste test in the NTK to see how close it was to the Telefunken and Mullard). Gold Lion tubes are the real deal….no argument there. They sound great. I don’t know how else to say this, but for me the Gold Lion (although a massive improvement over the stock tube) in the NTK sounded more modern to me.…less second-order harmonic distortion (which I like) compared to the more pricey tubes. The Telefunken has a texture to it that sounds thicker…more vintage sounding. Once you locate a Telefunken at the right price you will be equally surprised. And once it goes into the mic, you won’t look back. Again….it’s not subtle.

        Thanks for the comment and happy recording.

    10. Sheri Lee says:

      Thanks so much for posting this! I too, have a Rode NTK that was sitting in it’s case gathering dust. After reading this post, I got myself a Telefunken e88cc off eBay – and now I am in love with this mic! Vocals sound gorgeous, full and lush with this tube. As expensive as Telefunken tubes are, this was a lot cheaper than buying a Telefunken CU-29 (which I still may do because I’d love to compare the mics side by side).

      Regards, Sheri Lee
      PS. Love your music.

      • Dale Simmons says:

        You described my situation exactly. My NTK was in the case for YEARS as well…quite the opposed these days.
        Let me know if you get the CU-29….I love to hear the results of that comparison.
        And thanks for listening…

    11. Very nice post! You made me go for the Telefunken tube.

      I also changed the capsule to a RK12 from

      It’s totally different mic now! Warm and clean, no more gritty harshness and squashed high end.

      You can read about it and listen to sound examples here:

      • Dale Simmons says:

        Great post on your website Daniel…especially the samples. Thanks for connecting and posting the link…

    12. Dale Simmons says:

      Sheri and Daniel,
      First of all….please accept my sincere apologies for such a delayed response. Apparently I have an issue with my website…it’s supposed to be sending me email notifications when someone has updated a post with comments. That’s not happening. I’ll get that sorted out…

      Second….thank you very much for the comments. It makes me happy to hear that the post helped you out.
      It’s interesting that I caught your comments today…..I was just in the studio yesterday mixing a new track on which I recorded all of the vocals with the NTK and the Telefunken tube (still…never thought I would say that). The engineer was floored when I told him what mic I used…

    13. Jay Speight says:

      Hey Dale,

      Thanks for being such a resource on this topic. I’ve been considering upgrading the tube in my NTK for a while and reading your post has definitely helped make the decision to go for it. The only question that remains for me is if the Telefunken tube works with the 7 pin rode cable or if I will need to buy a different cable to use. Thanks!


      • Hi Jay
        If you’re using exactly the same tubes as I’ve referenced (which are higher quality REPLACEMEMTS of the stock NTK tube) then you don’t need to change anything except the tube itself. I’m still using the proprietary Rode cable that came with the mic.

        Also, there’s a free demo track on my website called Seeker’s Prayer that you should check out. All of the vocals were tracked with the NTK using the Telefunken tube. The version on the website IS mastered, but I have an unmastered version if you’re interested. The one on the website “might” be a little hot in the upper frequencies.

        Take Care,

        • Jay Speight says:

          Thanks, Dale. Sounds great! Yeah, I would love to AB it with the unmastered. I definitely hear what you’re talking about with the upper frequencies, but even so your vocal still sounds very clean and open compared to the sizzle of the stock NTK tube.

    14. What would the difference between NOS telefunken ec88 and new? I’ve found sources for both vintage NOS and new manufacture.


    15. Does anyone know how to change the tube Rode NTV mic
      or how the microphone is opened

    16. Hi really thanks because of the information .i always have problem with too much harshness with hi end frequency during recording with my NTK . so i was searching online and found out the Telefunken web site is selling the tube but lot cheaper than the prices that i see here some people already bought online. Is there any difference ?
      here is the link:
      It is $48 but i saw the price somewhere more than $150. can anybody help me ?

    17. Hi dale, thanks of the information, is the telefunken good for RODE k2? Thank You.

    18. I’m was ready to buy the NOS Telefunken E88CC, but I found out there’s a new version out, the Black Diamond Telefunken E88CC for a third of the price.

      Can anyone tell me if they are any good? They seem to be serious about it, but I can’t find any reviews anywhere. Any info would be appreciated.

    19. I am trying to change the tube in my mic Rode K2 for Amperex 7308 ? Or should I go for Amperex 6922 ? Does anyone have any experience with this? Which one would sound better for vocals ? Please let me know..👏❤️

    20. Great advice. I recently purchased both the RODE NTK & K2 mics (both tube). I installed a Golden Lion in one and the Telefunken in the other. Tubes ~ $45.00 each from The Tube Depot mentioned above. There is a BIG improvement in the sound of both mics. For greater warmth, I add a UA Solo 610 pre-amp and let the magic begin!

    21. Rich Vincent says:

      Any idea what brand tube the mic ships with from the factory?

      I just got an NTK for free. I’ll be replacing the capsule with a Peluso C12 style capsule and changing the tube. But I’m certainly not going to spend the $200 that tube depot wants for a NOS Telefunken. I’ll drop a a JJ 6922 in there for now, and if I ever run across a Mullard or something interesting locally for a decent price I’ll drop it in

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