Thread: Mystery of the Tube Mic

You do have it mounted upside down don't you? If not that could very well be your problem. The heat produced from the the tube and rising to the capsule can cause the issues you mentioned. If you mount it upside down heat wil travel away from the capsule not toward it. Besides the heat can damage the capsule permanently Since the sound degrades after it's been on for a while I would guess this is the culprit.

BTW, the voltage should always be set the same as the A/C in your country, never change this unless it's set wrong from the factory. You can damage some very expensive gear with an incorrect setting.

Big D, your advice is muchly appreciated. I didn't have it upside down at all. I'm going to give it a try.

I find it very troublesome that if this indeed is the problem, why they wouldn't have mentioned it in the long DO's and DON'Ts in the included instructions. Sounds like a good way to ruin a 300 Euro investment.

It's S.O.P. to "hang" tube mics. The manufacturers of tube mics (especially "budget" offerings) should mention this.

That may not be the problem though ... you might try replacing the tube. Just because it's new, doesn't mean it's running up to spec ... tubes can be funny like that ... especially cheap tubes made in China.

When a manufacture charges $4000 retail for a mic, they can afford to QC them, allowing every unit to run for hours and then checking to make sure they are up to snuff. But when you pay $300 for a mic, you can be assured that if your lucky, a short cursory QC was performed. In some cases they will spot check them, one out of ten or one out of hundred. So some mics with problems may slip through the cracks. Contact your retailer or the manufacturer immediately and tell them your problems so you have recourse later, if needed.

I find it very troublesome that if this indeed is the problem, why they wouldn't have mentioned it in the long DO's and DON'Ts in the included instructions.

I agree and as Kurt said it should be mentioned in the instructions. Especially with budget mic's as these are more than likely in the hands of novices who may not already know this. I wouldn't have known had it not been for an engineer explaining it to me many years ago. Of course after hearing the reasoning it makes perfect sense.

Good Luck

You fellas are superb. :D

I turned off the mic for a while to let it "cool". Then I turned it upside down and after a half an hour or so, flipped the 'on' switch. Fifteen minutes later, the mic hit the good point where it really warmed up. I started singing a little, monitoring from Cubase. Sounded good.

And it stayed! Still going strong, sounding beautiful. I wager to say, this might have fixed the problem. I hope so.

But I still have an uneasy feeling about it. If it uniformly displays this problem when turned right side up but not when upside down, would you consider this perfectly normal and let it slide, given that there were no other apparent issues with the mic? I'm quite satisfied with its sound.

Cheers, Dustin

It sounds like you solved the problem but just to be sure let it run for a few hours and test it once in a while. If the problem doesn't return I'd say your safe. If however you notice any issues do as Kurt said and contact the manufactuer right away.

I've been using the mic now for a few hours and it continues to sound just fantastic. Nothing like before at all. :D

Last Q for you: How much of a distance should I keep from the mic when singing? And where should the pop filter be placed between myself and the mic - at what distance?

There are no hard and fast rules on this. I vary it with the mic I'm using and how much room I want to pick up. Sometimes I'm 12" to 18" away others times it may be 3' or more. The key is to pay attention to the sound, when it sounds good your in the right place.