Problem with Go Between

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LetterBeacon
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Joined: Tue Apr 26, 2011 10:46 pm

Problem with Go Between

Post by LetterBeacon »

I own a JLM Go Between and a FET DI, but I'm having a problem with it at the moment.

It seems that everything that's plugged into the Go Between board has phantom power on it, whether the phantom power switch is engaged or not. I measure in on the + and - on both the inputs and outputs of the board, and I also measure it on the 0v (and therefore in the shields of the cables). There is no continuity between the 48v input pad and the other connectors, I measure 7K resistance between them (probably the 6.8k resistors), so I don't think I've shorted anything.

Does anyone have any ideas?

Thanks.

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Joe Malone
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Re: Problem with Go Between

Post by Joe Malone »

LetterBeacon wrote:I own a JLM Go Between and a FET DI, but I'm having a problem with it at the moment.

It seems that everything that's plugged into the Go Between board has phantom power on it, whether the phantom power switch is engaged or not. I measure in on the + and - on both the inputs and outputs of the board, and I also measure it on the 0v (and therefore in the shields of the cables). There is no continuity between the 48v input pad and the other connectors, I measure 7K resistance between them (probably the 6.8k resistors), so I don't think I've shorted anything.

Does anyone have any ideas?

Thanks.
If you have 0v wired to all XLR pin 1 and 0v on the power supply it would be impossible to measure 48v on the shields and 0v of course. What are you actually using as 0v ground to do your measurements from?

Remember if you turn 48v on and have no load for it the 10uF will hold 48v on the +/- in and out as there is no current to drain the volts. The 48v on the 10uF effects nothing as there is no current draw. If there was any current draw the 10uF cap will discharge instantly.

Otherwise it can only be your wiring and also check you do not have 48v wired to 0v on the GO between kit and also if you have 48v reg that it isn't shorted tot he chassis.
Joe :-)
JLM Audio
Capturing Audio without Injury

LetterBeacon
Posts: 7
Joined: Tue Apr 26, 2011 10:46 pm

Re: Problem with Go Between

Post by LetterBeacon »

If you have 0v wired to all XLR pin 1 and 0v on the power supply it would be impossible to measure 48v on the shields and 0v of course. What are you actually using as 0v ground to do your measurements from?
Apologies, I should have said that the shields are floating at the moment. I was connecting them up with a crock clip to pin 1 when I saw a spark which was when I noticed that I had 50V in the shields.

So do you think it's worth me connecting a condenser mic to the unit to discharge the 50V and then take measurements?

In the meantime, I'll double check my wiring.

Thanks!

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Joe Malone
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Re: Problem with Go Between

Post by Joe Malone »

LetterBeacon wrote:
If you have 0v wired to all XLR pin 1 and 0v on the power supply it would be impossible to measure 48v on the shields and 0v of course. What are you actually using as 0v ground to do your measurements from?
Apologies, I should have said that the shields are floating at the moment. I was connecting them up with a crock clip to pin 1 when I saw a spark which was when I noticed that I had 50V in the shields.
Should not be powered up at all until wiring is complete with all shields tied to 0v on GO between and 0v on power supply.
So do you think it's worth me connecting a condenser mic to the unit to discharge the 50V and then take measurements?
No just short pin 2 and pin 3 together and then short them to pin 1 to discharge with 48v switch turned off.
Joe :-)
JLM Audio
Capturing Audio without Injury

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