No sound from old microphone

[skogsgren]

Hi,

So I recently bought two old 60's Tandberg TM6's and I'm now trying to plug these into my computer but there is no sound. I have a Scarlett 2i2 interface and no matter what settings I try or how high the gain goes I get no sound except buzzing. At the highest gain the buzz is intolerable but I think I hear a faint voice if I scream right into them however that might be my brain tricking me to hear things that aren't there.
I've also tried hooking them up to a guitar amp with mic in but no sound there at all. They both have a 1/4" cable end that I connect directly into the Scarlett and then Scarlett to computer. I'll attach a picture of how they look. I'm new to microphones so I'm not sure if it is me doing something wrong or if the microphones are busted.

Any help is greatly appreciated.

 

[keith.rogers]

... I recently bought two old 60's Tandberg TM6's and I'm now trying to plug these into my computer but there is no sound. I have a Scarlett 2i2 interface ....

From the 2i2 user guide:

"Note the Scarlett 2i2 has no “Mic/line” switch – the Focusrite preamplifier stage is automatically configured for a microphone when you plug an XLR into the input, and for a line or instrument when you connect a jack plug."​

I'd try a 1/4" to XLR (M) adapter and see if you get a different result.

 

[skogsgren]

Thanks for the response!

Just returned from my nearest electronic store and plugged the mic into the adapter and the adapter to the xlr port. Tried turning the gain all the way up, made sure the xlr adapter worked but still no sound...

Any other ideas?

 

[keith.rogers]

They're dynamic mics from what I read so they should have a measurable DC resistance. Check that with a multimeter? Odd if they both behave that way. I assume they don't work in a PA either?

 

[skogsgren]

Thanks for helping me!

Unfortunately I do not own a multimeter however it does say 250ohms on the side of the microphones. Since I am not a native english speaker I am unsure what PA is.

 

[keith.rogers]

Unfortunately I do not own a multimeter however it does say 250ohms on the side of the microphones. Since I am not a native english speaker I am unsure what PA is.

The 250Ω is an impedance. I'd wanted to just measure to make sure there was no short-circuit or broken wire (0 or "infinite" ohms).

PA = Public Address, i.e., a preamp/mixer+amplifier+loudspeaker rig. Basically, I'm trying to understand whether these microphones work in any typical context, t.ex. to rule out just a couple of kaput mics, or cables possibly.

 

[arcaxis]

Found a Tandberg 3300X tape recorder manual that had some info on the TD6.

- The original mics had either a DIN type plug or a TRS (tip-ring-sleeve) 1/4" plug for a 'balanced' type of connection to equipment that had a 'balanced' input jack.
- When plugged into the tape deck the socket/jack in the tape deck connected pin 1 & 2 together to create an 'unbalanced' connection for the tape deck.
- The mics you have appear to have TS 1/4" plugs, so possibly someone had modified them by connecting the wires together that would have been on pins 1 & 2. Hopefully the modification was done correctly. The hum you're getting might be an indication it wasn't done correctly or a wire that came loose.
- If the adapter you had gotten simply changed a 1/4" TRS to an XLR, this may not work correctly. An adapter would need to adapt 1/4" TS to XLR.
- Can you remove/unscrew the barrels on the the 1/4" plugs and see if the are 3 wires with one wire connected to the center pin of the plug and two wires connected to a longer lug extending back. If you can get a close up pic of it to post, it may help.
- If the cable at the plug end does have 3 wires and you're up to soldering, replacing the 1/4" plugs with XLR plugs would get it connected to the 2i2 properly. Each wire would need to be identified to do this.

- The specification for the sensitivity shows 0.1mv/ubar(microbar). I'm more familiar with the usage mv(millivolts)/PA(pascals), but I think converted the sensitivity of the TM6 would be 1.0mv/PA (based on 10ubars=1 PA), which is not much output compared to other typical dynamic mics. The TM6 would need a lot of gain in the preamp to get usable sound or a quite loud sound source. The 2i2 might not have the needed gain for this mic, but can't hurt to give a try.

 

[skogsgren]

I know the USB interface is not a problem, since it works with guitars and another interface (Scarlett Solo) showed no difference. I also tried with a different computer but there was no difference there as well.
As I don't have a multimeter I improvised and grabbed an electrical tester to check if there was a short circuit or broken wire (It should be able to I think) but it showed that there was continuity in the circuit. I checked while it was plugged in the interface, unplugged and on different parts of the mic; 1/4" plug to case of microphone (Since the case is metal), 1/4" plug to grill of microphone.

Thanks again for helping me understand this.

EDIT: Posted without updating the page and missed your response Arcaxis. I think he modified it himself as he asked me if I wanted both of them with 1/4" (Since one of them was worn down). It appears as if a black wire is attached to a metal bar that itself is connected to the center pin. There is a white wire soldered to a larger metal bar on the bottom and a copper wire soldered to the base of that metal bar. Sorry if my word choice is a bit confusing, will attach close ups of the soldering below.

 

[keith.rogers]

Found a Tandberg 3300X tape recorder manual that had some info on the TD6.

- The original mics had either a DIN type plug or a TRS (tip-ring-sleeve) 1/4" plug for a 'balanced' type of connection to equipment that had a 'balanced' input jack.
- When plugged into the tape deck the socket/jack in the tape deck connected pin 1 & 2 together to create an 'unbalanced' connection for the tape deck.
- The mics you have appear to have TS 1/4" plugs, so possibly someone had modified them by connecting the wires together that would have been on pins 1 & 2. Hopefully the modification was done correctly.....

I think you might be on to something there. Looking closely it seems obvious that the 1/4" TS plugs are not original. So, either of the things you suggest could have happened - they weren't wired correctly, but if "backwards" they might have worked in a PA that was accepting a TS microphone level, but would not work in a converter plug, or the converter plug was expecting 1/4" TRS and not 1/4" TS.

I'm guessing if OP doesn't have a meter they might not have a soldering iron either. Probably best to take the 1/4" plugs off and put actual XLRs on at this point.

 

[skogsgren]

Funny enough I do have a soldering iron but I don't have much skill with it. Should I try to reverse the cables myself or would it just damage the mic if done incorrectly?

 

[keith.rogers]

I know the USB interface is not a problem, since it works with guitars and another interface (Scarlett Solo) showed no difference. I also tried with a different computer but there was no difference there as well.
As I don't have a multimeter I improvised and grabbed an electrical tester to check if there was a short circuit or broken wire (It should be able to I think) but it showed that there was continuity in the circuit. I checked while it was plugged in the interface, unplugged and on different parts of the mic; 1/4" plug to case of microphone (Since the case is metal), 1/4" plug to grill of microphone.

Thanks again for helping me understand this.

EDIT: Posted without updating the page and missed your response Arcaxis. I think he modified it himself as he asked me if I wanted both of them with 1/4" (Since one of them was worn down). It appears as if a black wire is attached to a metal bar that itself is connected to the center pin. There is a white wire soldered to a larger metal bar on the bottom and a copper wire soldered to the base of that metal bar. Sorry if my word choice is a bit confusing, will attach close ups of the soldering below.

Assuming there is not a short-circuit causing that continuity, it looks like the balanced to unbalanced wiring was done consistently, at least. ("Backwards" is impossible to tell without color codes on the wires, and only will matter when mixed with other mics if they are - then they will be out-of-phase, but still working.)

 

[keith.rogers]

Funny enough I do have a soldering iron but I don't have much skill with it. Should I try to reverse the cables myself or would it just damage the mic if done incorrectly?

I think it's Ok the way it is.

Which, of course, doesn't solve the original problem. Except your 2i2 does need to see a correct XLR, which may not be solvable with a 1/4" TS to XLR adapter. I'd replace the plugs with XLRs - t least one of them, to test.

P.S. Just my own strongly held opinion, but if someone doesn't have a multi-meter, they shouldn't be messing with a soldering iron and electrical components... It makes it *really* hard to understand why things aren't working.

 

[arcaxis]

It looks like there are 3 wires, white, black, and a copper shield, so if you're up to giving a bit of soldering a try, we can probably give some guidance to replace the 1/4" with XLR's. It doesn't look like the job the previous person did was done very well, but appears that is wired to be 'unbalanced' correctly.

 

[skogsgren]

I'll try to contact the seller first and see if he is willing to accept changing the 1/4" plugs to XLR's because I think he's probably going to do a hell of a lot better than me exchanging those. However if he isn't willing I will return for more help.

Oh and thank you, both of you for all of the help! I'm constantly surprised by how kind some people are here on the internet to help a beginner with these types of things.

 

[Ainaudio]

Mics and cables are symmetric. Desolder TS connectors and solder XLRs on. It will be more right in all aspects. Cable shield to contact #1, black wire to #2, white wire to #3. Question about polarity is open and must be compared with someone Shure mic and right XLR cable. If you state out of polarity situation - resolder white wire to #2 and black wire to #3 contacts.