Rode NTK - Should you upgrade the tube?

tombuur

tombuur

New member
Well, I changed the tube in my recently acquired NTK for a $99 NOS Siemens tube. During the process I recorded my own lousy voice before and after the change leaving everything untouched. I would like to share the results with you. The file is 1.7 MB in 320 kbit/sec mp3, so if about 12 people listened to it that would exceed my daily allowed traffic. If someone could host it, I will gladly mail the file, and you could all comment on the differences you might hear.
 
tombuur said:
Well, I changed the tube in my recently acquired NTK for a $99 NOS Siemens tube. During the process I recorded my own lousy voice before and after the change leaving everything untouched. I would like to share the results with you. The file is 1.7 MB in 320 kbit/sec mp3, so if about 12 people listened to it that would exceed my daily allowed traffic. If someone could host it, I will gladly mail the file, and you could all comment on the differences you might hear.
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I'll host it. Email me at kosull03@postoffice.csu.edu.au
 
So we've got a volunteer to host the mp3 file which should shortly appear below here.

This is what it is all about: I recorded my average voice (I am a guitar player who sings, not a real singer, so bear with me). I did this with stock tube in the NTK after 1 hour of warming up. Changed the tube, warmed up and repeated the recording with everything else left untouched. The NTK is recorded through a TC-Helicon Voiceworks which should have a decent preamp and it's own AD-converter. Then through SP/DIF I recorded in Sonar 3. There are no effects, eq, compression or anything added. I guess you can do this yourself if you would like to test that.

In Sonar I chopped up the phrases and reassembled so you will hear ABABABAB, i.e. the same lyrics are repeated, but with a different tube. The question is which one is A and which one is B? Can you hear the $99 difference between stock tube and NOS Siemens? Please comment, then after a number of posts I will reveal what is what.
 
no appreciable difference. 2nd one a tad brighter but nothing you couldn't eq in if you liked that. Not worth the upgrade IMHO
 
Nobody else want to try a guess or comment, before I reveal which one is which? I can see several have view this thread, so you should be able to state what you think, also if you can't perceive any difference.

Tom
 
No real appreciable difference, IMO. Definitely not a $99 difference. Try a $10 tube. :)

Tubes can sometimes make a pretty big difference, it's just that these two particular tubes sound the same in your mic.

Taylor
 
NL5 said:
Well, on my computer speakers, A sounds slightly better, and I do mean SLIGHTLY.
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What sounds better about it, to you? I would say they sounded slightly different, and I do mean slightly. I wouldn't characterize one as better than the other. Just curious as to what you liked better about A.

Taylor
 
Okay, no new comments for 24 hours. So here we go:

A is the stock tube. B is the $99 + postage Siemens NOS tube.

Personally, I can't tell any difference at all. So to me it has been a waste of money. Don't know if my ears catch all the treble (53 years old), so I won't exclude the possibility that some of you can hear a difference.

When it comes to guitar amps, I don't doubt that the Telefunken I got for free with an old Fender amp sounds better than the original Sovtek in my Twin Reverb preamp. But the Rode NTK, nope, I can't tell any difference. Perhaps another tube (Philips JAN?) would sound better, but I am not going to try, unless someone can demonstrate the difference to me in a way similar to what I have done here.
 
slobbermonster said:
is there something about the NTK you don't like?
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Yes, I think the highs aren't smooth enough. That's why I changed the tube. Also I wanted a bit more low. But that can be fixed with EQ.

I know some people prefer when the mics sound best without processing. On the other hand, considering how you apply all sorts of effects to a mix, what's the big deal if you have found the best EQ settings for a voice. You can save them as a preset, then that's the sound of "your mic".

But when the highs aren't clean, there is a problem you can't easily fix. I have heard that this should be a general problem with tube mics, not only NTK. Is that so?
 
Yep,

Not much difference. The NTK is such a design, where the tube is connected as a cathode follower, with four BJT's in parallel (thank you Gus!) as a load. The frame grid 6DJ8 is not exactly a tube for a microphone use and I was kinda surprised for this choice, but in this configuration its flaws (once again, as a microphone impedance converter) are probably not that prominent. Besides of NTK, the only use of this tube I ever heard is an EAR mic by Tim de Paravicini, (this guy always knows what he is doing). Anyway, in NTK transfomerless design the tube doesn't do much for a 'color', but serves rather as an idea of being "tube inside".
Change of capsule here will make much more difference, than a tube change.
BTW, it would be interesting instead of 6DJ8 (ECC88) to try to use Russian tube 6N1P. I am not sure if NTK power supply could handle almost twice as much of heater current (600ma vs. 375ma), but 6N1P IMHO is much better sounding tube and cost about $6.
But once again, I am not responsible for two things:
1) You blow your PSU because of higher filament current of 6N1P
2) Because of kind of schematics, you will hear any difference.
 
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Don't know enough about electronics to understand this. Are you saying that the NTK is not really a tube mic? In other words, they just put a tube inside to fool us all, but the tube doesn't affect the sound in any significant way.
 
tombuur said:
Don't know enough about electronics to understand this. Are you saying that the NTK is not really a tube mic? In other words, they just put a tube inside to fool us all, but the tube doesn't affect the sound in any significant way.
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Hmmm.... technically speaking, it is a kinda tube mic, but if you are talking about "tube sound" (whatever it means), you are pretty much right... To put it simple, it is not exactly a smoothie-tubie kind of sound.
 
I get very warm full tracks with my NTK, roll off a little 12k and 500 (less boxy) and it sounds great. I do use it less than my MD 1B, but it still gets a fair shake now and then
 
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