Troubleshooting a secondhand mic (MXL V69 Mogami Edition)

the_warden

New member
Hey Guys,


Been lurking and reading here for awhile but have ran into a snag with my setup.

I recently purchased a used MXL V69 Mogami Edition tube mic off of ebay and first tested it last night. Ensuring all of my connections were good, I turned on the power supply unit and the phantom power on the Scarlett 8i6...

...nothing. No response whatsoever. I shut off the PSU and phantom power, disconnect mic and open it up to inspect internally. Everything appears intact and mic has not been modded, still contains original tube as well. Again, I inspect all connections thoroughly. I power the mic up and again check my monitor levels, ensure PSU is on and phantom power engaged. Still nothing. The tube appears to be in good shape and almost new as well, but I have no prior experience with tube mics so it could be something that I am unable to see.

I'm bummed out to say the least because this mic looks almost brand new and I would really like to add it to my gear. I am expecting to come home and check the cords to make sure it is not an issue with them but I do not have another 7 pin cord though, unfortunately.

How can I further the troubleshooting with this mic?

Is it possible the tube is no good anymore and can a bad tube kill the signal like that?

I'm hoping it's just the tube, which I intended to replace anyway, but I'd really not want to have to deal with the hassle of sending it back and all that; but if attempting to locate the problem is going to take hours of special attention and equipment or component swapping, this thing is going back asap.

Any experience or advice that you think will help is greatly appreciated.
 
That's what I was thinking at first and initially had it set up with no phantom power. After I wasn't getting a signal I wondered about it and consulted the mic manual. It stated that phantom power was required...I kinda thought that was odd too, but like I said, no previous experience with tube mics.
 
There is another manual with the mic that states that it uses phantom power but I am still skeptical. Any mic that doesn't require phantom power, will simply not use it, even when engaged.

This is a used mic and I am the second owner. It does appear "like new" though.
Power supply does work.

I should add that I tested other mics before and after this mic and all others (standard condensers) were working fine.
 
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After the 3rd and 4th tests with this mic, I have come to the conclusion that there is either some kind of damage to the inside circuitry (which I am not knowledgeable enough to engineer yet) or the capsule.

Before I was getting no response at all and I made sure none of the cords had shorts. For some reason, using the exact same setup, I am getting what sounds like radio static with a low pass filter on it but nothing seems to be getting captured by the capsule (vocal or instrument).

Sending it back but thanks to those who checked it out and tried to help/responded.
See ya around.
 
The only other thing that I could think of checking was to take a look at the multi pins on the microphone to power supply cable to make sure that one or more of them hasn't bent over.
 
Mic cables were inspected upon receipt of the mic and I further troubleshot those thinking it was possibly a short.

Nah, its at the 115 setting and I'm in US. That would have been something obvious that I may well have missed though. Thanks.
 
Well it is an older make and it looks a little more complicated than others ive seen online (see pic below). It's not one of those ones where you just pop it out and replace. New tubes are on the way though, but may end up being standby's for another mic if this doesnt work out. I don't want to risk modifying it then not getting my money back because I did so.

Taking it to a tech at a local music shop tomorrow so they can maybe spot something.

photo(24).JPG
 
I guess you just unscrew the mounts for that little retaining ring to replace the valve.
Be sure to let us know how you get on.
Good luck. :)
 
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