Rode NTK - Should you upgrade the tube?

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tombuur

tombuur

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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.
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.
 
I would say the new tube would be "B". Do I win a prize? How about the mic! :)
 
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
 
negligible, I don't think there is enough difference to warrant the expenditure.
 
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
 
Well, on my computer speakers, A sounds slightly better, and I do mean SLIGHTLY.
 
NL5 said:
Well, on my computer speakers, A sounds slightly better, and I do mean SLIGHTLY.
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?

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.

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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