AT3060 noise problem...

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johnnypraze

johnnypraze

Hip Hop Head
I recently bought a used AT3060 mic.

I hooked it up today to check it out and left it sit for about 10 minutes for the tube to stabalize (as stated in the instructions) and when I went in for a test I got a whole bunch of noise. The kind of fuzz you hear when something is turned up too loud.

The noise is constant. When I speak in the mic my voice sounds clear and fine but you hear a constant backround noise. Its very prominent.

Also, the level meter in my DAW is bouncing around some?

I'm pretty sure its not a ground issue.

The noise also goes up and down with the gain almost as if there is too much but the noise is there even at minimal gain.

Could the mic or tube be bad?

Any ideas???
 
I have the AT3035 which does not have the tube and i don't get any signals like that.
What are you hooking the mic into? mixer pre's? standalone?
 
Sounds like it will have to go back to AT. That is no standard tube, and the electronics are all SMT :(
 
I just got it yesterday. Bought it used off of Ebay.

Its going into a Tampa pre-amp.

I use to have the 3035. None of my other mics have this problem.

Looks like I may have gotten screwed huh...?
 
johnnypraze said:
I just got it yesterday. Bought it used off of Ebay.

Its going into a Tampa pre-amp.

I use to have the 3035. None of my other mics have this problem.

Looks like I may have gotten screwed huh...?
Click to expand...

Your 3060 is an old twist on the starve plate designs they use today, in that, it uses a small triode designed specifically for low voltage. With standard dual triodes you can usually test them in a guitar amp or audio circuit and attempt to drive them into microphonics by tapping the tube lightly with the erasor end of a pencil. If the the tube exhibits microphonic characteristics, then it is discarded.

It's quite possible this minature triode was damaged before being sold (eBay ya know), or during shipping. My recommendation is for you to swap it out with an NOS Ratheon 6418, since they are fairly cheap. More than likely it's the tube that is faulty, and not the circuit or transformer.

Without seeing the mic schematic, I can only take a guess.
 
sound125 said:
Your 3060 is an old twist on the starve plate designs they use today, in that, it uses a small triode designed specifically for low voltage. With standard dual triodes you can usually test them in a guitar amp or audio circuit and attempt to drive them into microphonics by tapping the tube lightly with the erasor end of a pencil. If the the tube exhibits microphonic characteristics, then it is discarded.

It's quite possible this minature triode was damaged before being sold (eBay ya know), or during shipping. My recommendation is for you to swap it out with an NOS Ratheon 6418, since they are fairly cheap. More than likely it's the tube that is faulty, and not the circuit or transformer.

Without seeing the mic schematic, I can only take a guess.
Click to expand...

Thanks for the advice...
Where might I look for one of these tubes?

I tapped the tube with the erasor end of a pencil but nothing happened. Does this mean the tube is bad?
 
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johnnypraze said:
Thanks for the advice..

I tapped the tube with the erasor end of a pencil but nothing happened. Does this mean the tube is bad?
Click to expand...

You would only do that when the tube is in an active circuit, which as I explained is done with standard dual triodes in a guitar amp or audio circuit. If the tube goes microphonic, you replace it. This is also done in conjunction with testing it for emission, value, leakage and shorts. Since you don't have the equipment to test it, my suggestion is to just replace it, as an inexpensive alternative.
 
Thanks alot...

The mic was not modded in any way.

You are sure that tube will fit?
 
johnnypraze said:
Thanks alot...

The mic was not modded in any way.

You are sure that tube will fit?
Click to expand...

Yes, it should be a direct replacement for the AT3060.
 
Given that you just picked it up, I would return it or file a complaint against the seller. It could be the tube; however, the leads from the board are soldered to the tube, and the tube is glued in place. This is nothing that cannot be overcome, but if you swap the tube and it doesn't work, then you are still back to returning it, but now you've "modded" it and the seller may refuse on those grounds.

Bottom line is the seller should be held responsible.
 
Well, I already left good feedback like a dummy. (Never been burnt before)

Everything is in like new condition, and I was leaving feedback for some other things and just copied and pasted them all with out thinking to test it. Lesson Learned.

So I assume it will be that much harder trying to get a refund.
 
johnnypraze said:
Well, I already left good feedback like a dummy. (Never been burnt before)

Everything is in like new condition, and I was leaving feedback for some other things and just copied and pasted them all with out thinking to test it. Lesson Learned.

So I assume it will be that much harder trying to get a refund.
Click to expand...

Yeah that sucks sometimes, although I had a guy try a chargeback after leaving positive feedback :confused: I think he was confused because he gave up shortly thereafter.

If you're handy with soldering you will be able to change the tube, so good luck, I hope that is the problem.
 
johnnypraze said:
Thanks alot, you've been a tremendous help...

I'm Going to order two of these: http://cgi.ebay.com/JAN-6418-CE-932...ryZ67816QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

Those are alright I assume? Looks just like mine.
I'm pretty decent with the soldering iron and the points are decently spaced.

Any advice on installation once I get the tube?
Click to expand...

I can't promise you that the the replacement is going to work. But I can tell you that one of the reason solid state replaced tubes, is because tubes are easily damaged and more often than not are the problem, especially if someone dropped the mic, or mishandled it during shipping.

Make sure you orient the replacement tube to the one you remove, before soldering. Since you are not dealing with high plate voltages, I think this is a good learning experience, and, if successful, will build confidence in other repairs you encounter down the line.

BTW, I like JAN tubes because of their heavy duty micas and rugged construction. Hopefully, this repair will last a long time. Best
 
One last question...

Do you think my pre-amp could have ruined the tube?

I was in the studio room checking the pre-amp and noticed that I left the tampa on 1200 ohms. I was playing with the sound characteristics of another mic and never switched it back.

None of my mics mind switching the ohm load, but could the AT3036 be different since it has a tube. Its a 400 ohm mic and when I gave it the phantom power to warm up, the pre was left at 1200 ohms and the gain up relatively high.

Could this have caused the issue? If so, how likely?
 
johnnypraze said:
One last question...

Do you think my pre-amp could have ruined the tube?

I was in the studio room checking the pre-amp and noticed that I left the tampa on 1200 ohms. I was playing with the sound characteristics of another mic and never switched it back.

None of my mics mind switching the ohm load, but could the AT3036 be different since it has a tube. Its a 400 ohm mic and when I gave it the phantom power to warm up, the pre was left at 1200 ohms and the gain up relatively high.

Could this have caused the issue? If so, how likely?
Click to expand...


My guess is that the issue is probably a result of damage to the tube from impact, mishandling, or an eBay seller trying to dump it.

The phantom power from the Tampa is 48 volts, which is what feeds the 6418 tube with a plate voltage around 22vdc. Your variable impedence settings shouldn't be a factor nor the gain control.

Since you aren't able to test the circuit or tube for comprehensive emission, value, shorts or leakage, your best bet is to put the mic away for awhile and wait until the tube arrives. It's the least expensive repair you can perform at this stage, so I don't think you have much to loose.

Without evaluating the circuit, I don't know with any degree of certainty what other underlying problems the unit may have underwent.

Best
 
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