cal me backward.. but I haven't bought anything on e-bay in my life.. I find the bidding thing just iterating..
Would rather know the price upfront and then look for the best deal..
Do you know of any retailers?

Just look for items with a "Buy it Now" price.

These are often by dealers.

I have a vintage Amperex Holland from 1969 for sale that improves the signal quality by light years on Rode NTK and reduces the sibilance problems MAJORLY.

Check my signature for a link, and good luck bidding.

Not really great forum ettiquete to bump every slightly relevant thread with your for sale ad, when there's a whole forum for these ads.

thumbsup

Back on topic, I've been thinking about replacing the tube in my NTK, but honestly I've been mostly happy with the stock tube Rode put in there. It's some stock chinese tube with a star on it. I've looked it up before, but I can't remember what it is now. I'm going to replace it after reading this, though.

Man, I love the stock ntk sound for hip hop vocals. I never thought about replacing my tube in there. But it seems like it would be a great way to get some new life in the mic and start using it in other applications.

I was a little skeptic too about changing the tube in my Rode K2.
But I finally decided to give it a go.

I'm gonna tell you this:
If you are happy with the stock tube, you are going to be blown away by changing it with A GOOD NOS TUBE. You can give it different flavors.

I got a Telefunken E88CC gold pin (the real version, not the fakes) and an Amperex USA 6922 gold pin PQ white label.

They both had a major improvement over the sound.
The sound of the stock tube (which I liked before) now seemed hollow with metallic highs.

The Amperex made me smile, made me say WOW, the mic sounded warm but clear and when I added highs with an EQ they didn't get harsh.
Awesome.

Yep,
Replaced the stock Sovteks for two 1974 (matched & Balanced) Mullard E88CC tubes in my K2s and now I actually LIKE them for vocals..
Before they were clean but brittle and high/mid-ish, I used them for room mics and the odd thing here and there and liked them well enough
BUT
After the NOS tube change they have much more D E P T H
and exhibit a vast improvement to the width and scope of whatever they are honing in on. I use them in stereo mostly and they actually made my stereo image tangibly wider right away. I now hear fuller/richer/rounder lows (on any source) just within the microphones themselves..
I have heard it said that the best upgrade tube for the K2 (for satin sheen highs ie for female vocals) is a 1960's or other NOS Siemens tube. I actually prefer more body and less sheen (hence the Mullards) but realistically, removing the stock (good enough to do the job and still keep the price competitive) RODE tube and installing a valve with more sonic grace is something all NTK & K2 users should STRONGLY consider..

Nah, scratch that.. Just do it!

PS. keep your old tubes incase you need service from RODE later down the line and don't send your mic off without the STOCK tubes in.. that'd void your warranty : (

I have owned my NTK for a few years now but only came across the idea of upgrading the tube a few weeks ago. So for $30 I bought a Electro-Harmonix Gold 6922 tube as a replacement. I was of course curious about the difference between tubes, so I setup a test.

Like a lot of synths, my Roland Gaia allows you to record a phrase and play it back on any of its effects. Using this ability, I had a mogami instrument cable going from the mono output of the gaia to a monitor. I miked the monitor with the Rode NTK with a high quality mic stand that wouldn't move its positions. I then went through my presonus firestudio 2626 (not the best I know, but still good) into Cubase 5 and recorded a basic recorded phrase using 6 different synth effects with the stock Sovtek tube. I then took the NTK off the stand (without moving the stand) and swapped the tube with the EHG 6922. After putting the mic back on the stand (and measuring distance to ensure zero mic movement) I recorded using the exact same phrase, going through the same 6 effects, still using all the same levels. Overall, absolutely nothing was changed, accept the tubes. I measured the mic distance to the monitor grill to the same tenth of an inch; so any change in mic position would be extremely small. Attached are the results. The only effects used on the tracks were a Fabfilter Pro-L (very transparent limiter) and Apogee's UV22HR dither, going from 24 to 16 bits. I then converted the wav. files to 256 kbps mp3.

The results were very surprising; the EHG tube upgrade makes a substantial difference. Notice the smoother highs and more coherent lows along with the clearer more open sound overall. I was going to leave the tracks anonymous but the difference is so large, I figured that there was no point. I am extremely glad I decided to change my tube, though I wish I did it along time ago. I'd recommend anyone to do the same.

...while it sounds as though you're pleased with your tube upgrade, in reality you swapped out the stock grade Sovtek tube for higher quality Sovtek tube (Sovtek and Electro Harmonix are both brands manufactured by New Sensor Corp.)...

...in my experience with both the NTK and K2, upgrading to a high-quality gold-pinned NOS Siemens (Germany) or Amperex (Holland) 6922 will provide a more noticeable improvement on the mics' sonic characteristics...worth the extra expense of seeking out a low-microphonics tested NOS tube...

...similarly, I've swapped out the Electro-Harmonix 6072A tubes (stock in my Stellar and Advanced Audio tube mics) with selected NOS GE 6072 tubes resulting in measurable sonic improvement...of course, due to the variation of quality in NOS tube variants, YMMV...

The difference between the stock and EH is surprising to me. The EH brings out more of the body/beef in your tones.

I upgraded my K2 tube to an Amperex and am very happy with it. Clearly, imho the EH is an improvement in tone based on your files.

At first, because I was somewhat skeptical about how much of an improvement a tube upgrade would make, I only decided to spend $30. But now I will likely end up getting the NOS Siemens tube; thanks for the tip on the "low noise-microphonics tested", it's cheap to get it tested, so I might as well.

I have a NOS Tesla 6922 in mine. Purchased it that way off the classifieds here and have felt no need to change it. It's not at all sibilant. I've used it on vocals, acoustic guitars, and guitar and bass cabinets with no issues.

I ended up returning the EHG 6922 tube and buying a used NOS Amperex 6922 PQ (with a low noise and microphonics test) from tubedepot, so I will be repeating the test I did above with the Amperex in a few days when it arrives.

Round Two: Stock Sovtek 6922 Tube vs. Amperex PQ Gold U.S.A. 6922 Tube

I repeated the same test as above exactly the same way: same synth, monitor, recorded phrase, effects, levels, mic measurements, etc. (I made notes from the first test on the mic measurements from the speaker grill and sides/top/bottom of the floor monitor ensuring same mic position; I also kept the mic stand in the exact same position from the last test, knowing I would repeat it). I also made sure the db levels of the two "stock" tests were exactly the same. I did this by matching the db level of the second "stock" track, to the first "stock" track; obviously while simultaneously changing the "amperex" track level by the same amount to ensure that any perceived volume change is the difference of tubes only, not the test itself. This way you can compare the Electro-Harmonix Gold tube to the Amperex PQ Gold tube as well. The only difference in the tests is that the second test overall isn't as long because I shortened each effect phrase by a measure; in the first test, it seemed too long between synth effects changes.

The results...the Amperex PQ sounds absolutely amazing! A clear improvement above the EHG, although one would expect this with the substantial price difference. Overall, I am very pleased with the Amperex PQ.

Anyone know the best place in the UK where I can buy an amperex 6922 to upgrade my NTK? Should I be considering any other NOS tubes?
Thanks. joe

I decided to re-post this test in a more coherent way. Looking back, it was pointless to use the limiter and dither; so this time I split up the exact same files from the above test of the stock vs. amperex gold tube, with no effects what so ever, and directly exported each sample as a 320kbps mp3 file.

I put a NOS Tesla tube in my NTK and it's seen a lot more use on vocals these days. It was an early NTK (12 years old or so?) and I always thought it was a pretty smooth-sounding mic anyway, not harsh or brittle all as some other posters have described it. But the new tube improved the sound and things seem to sit a little more cozy in the mix now.

Changed tube with an old Telefunken and JJ. Changed also the capsule from microphone parts, one with a RK-47 and one with a CK-12. Can only recommend the capsule swap, its very easy and the difference is really nice:
Rode NTK-Mod | Crystalhorizon Records | Alexander Nantschev

Just looking at this in 2019, upon buying my own NTK.
Have we seen the price on this tube in 2019?
whew!