Replacing Tubes In Tube Mics?

[danevaz]

Hi All,

With the approach of the holiday sales season, I'm in the market for a vocal mic for my baritone/tenor (James Taylor meets Jobim) voice. At AES last month in NYC I got to demo some of the WARM tube mics. Their WA-47 clone seemed to flatter my voice and downplayed an annoying grit I have in my voice.

I asked their rep what happens when the tube goes - do I have to send it into them to get changed (as I had to do with a Mojave tube mic I own). He just shrugged and replied - "no, you're on your own with the tube change."

So, how do you guys handle tube replacements in your tube mics?

Given that many vendors trumpet their use of NOS tubes and "custom" or hard to find tubes, might not it be difficult to find the same model replacement tube? And wouldn't replacing the original tube with one not provided by the original mic manufacturer, change the sound of the mic?

Thanks in advance for any insight into this matter.

Danny V.

[albee1952]

Just my thoughts on this. Some depends on what tube they use in the mic. Years ago, my first tube mic was the MXL V69 Mogami and that used a 12AT7, which can be found most anywhere and from several manufacturers. I purchased a pair of NOS Mullards from an eBay seller and swapped out the chinese tube and it did get better sounding. My current "go to" tube mic is the Miktek CV4, which uses a NOS Telefunken tube(can't remember what the number is). I asked Miktek if I should purchase a few spares and they replied that they had stock to cover probably 20 years so I shouldn't worry about it

I am a firm believer in having spares, so maybe buy 1 or 2 from WARM, just in case. Most tube mic specialists that I have spoken with have said the tubes should go 10 years easy as they don't see much abuse in a mic(all bets are off if the mic is dropped). Some tubes are soldered in and some are in sockets. I would open the WARM mic and if it has a socket, then replacing it yourself is probably going to be fine. If its soldered in, I would send it back for repair, but I know many that would still tackle it themselves

[The Weed]

I had a Rode NTK and then a Rode K2. Both had easily replaceable tubes and yes, different tubes will change the character of the mic, some a little some a bit more.

I changed direction with my latest mics, settling on a Sennheiser MKH 416 and a Neumann TLM 49. The TLM 49, according to Neuman, is tuned to be like a tube and, having used it to replace some VO done with the K2, at least for my voice, it is. I also like the fact that I don't have to buy tubes or wait for it to warm up. As always, YMMV.

On tube life, I asked Rode how long the Sovtek 6922 would last in my K2 and they said 1,000 to 4,000 hours depending on use and abuse. Also realize that tubes usually "fail" gradually, so it may take a while to realize. I replaced mine every 12 to 18 months.

[Ben Jenssen]

The only tube mic I own says Protube on the front. I bought it used in the nineties. It uses EC92 tube, and I found them easily on the web. I slid off the enclosing metal "tube" to reveal the insides, swapped the tube in the socket and was a bit disapointed that I didn't hear much difference. Really very easy.

I remember being adviced not to touch the tube glass, as that would leave marks that might shorten its life.

Off topic: I don't know anything about this mic except it was part of a stereo set. The external power supply that I have has two connections. I find nothing on the web. I suspect it might be a sixties eastern european design, but I don't know. It sounds ok, but I never really explored its potential. Any info would be great. Putting it out there just in case any one has any info, or else ignore this.
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[Muddy-T]

Originally Posted by danevaz

So, how do you guys handle tube replacements in your tube mics?

Given that many vendors trumpet their use of NOS tubes and "custom" or hard to find tubes, might not it be difficult to find the same model replacement tube? And wouldn't replacing the original tube with one not provided by the original mic manufacturer, change the sound of the mic?

The WA-47 uses a Slovak JJ Electronic 5751 tube. Very easy to replace.

https://www.jj-electronic.com/en/

https://www.jjtubes.eu/preamplifying-tubes/5751


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