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I own a RODE NTK mic, and am not that happy with the sound. It's brittle, and not very focused.

I would love to get a better mic, but the budget is a little restrictive. So instead, I ordered a replacement tube for the mic, in the hope that I could improve the sound.

The tube I chose was a NOS Philips E88CC/6922 SQ from Holland.

I recorded two test tracks - one with the old tube, and then the new to compare any sound difference (which I believe is very apparent).

Here's the gear I used:

- Maton Australian Series Jumbo Acoustic Guitar (with month old strings)
- RODE NTK mic
- Sebatron vmp-2000e preamp
- LynxOne audio card
- Cubase SX (24bit, 44.1k project)

Here's what I did:

- I set up the mic (with the stock standard Chine tube) through the pre, and left them both turned on for about 45mins, to allow the tubes to warm up.
-I set the preamp controls to transparent, neutral settings, with no eq and low tube gain.
- I set the mic up a foot away from the guitar, pointed between the soundhole and beginning of the neck.
- I recorded a basic strumming pattern.
- turned off the mic, and replaced the tube with the NOS Philips one.
- set up the mic in exactly the same position, turned the mic on, and left it to warm up for 45mins.
- repeated the recording process, same strum, same position, same distance from mic.

I applied no compression, eq, and did not normalise the files, so you can hear volume diferences.

I coverted the 24bit files to 16bit with dither etc.

I then used Lame to convert the tracks to 320k mp3s

I'm not going to say what I think the differences are, because I want to hear what you all think!

I have never been up close and personal with a highend mic, like Nueman etc. How does the NTK with the new tube compare?

Here are the links:

Philips -

Chinese -



bap Fri, 08/12/2005 - 09:58

I just tried listening to these samples but they seem to be unavailable now. I replaced my stock tube in the K2 with a Mullard NOS and like the difference as well.

Sork, if the NTK is like the K2 then all you need to do is remove the little plastic support bracket that holds the top of the tube and then pull the tube up off the pins. My new tube was a little tighter going in than the original was coming out.

The K2 uses a 6922 twin-triode valve [tube]. The NTK is probably the same but be sure to check your documentaion so that you get the right type for replacement.