Topic: UA-5 overheating problem??? (No, mic problem)

[SmokinJoe]

I've had a strange problem the last 2 shows, and I'm not pleased.    Running LSD2 > Hydra > W+Mod UA-5 > optical > H120 and then at some random point part way through the show the right channel level will go nuts. 

It starts off with a moment of silence, then it pegs.  See pictures and MP3 sample below.  I've run this combination before without problems.  Nothing physical is happening when this occurs that I know of.  Nothing obvious like someone tugging on wires etc.

I think I can rule out the optical > H120 piece.  At the same time as this sample occurred I was pulling another patch with UA-5 > gray box > optical > JB3.  The JB3 has the same glitch so it must be upstream from there.  The new Hydra cable looks good... I inspected the solder joints, and it looks fine.   I set this all up at home to see if I could repeat it.  I could not.  I wiggled the cable ends at the UA-5 and the mic, no hiccup. 

The difference? Well one difference is heat... At home it's layed out on a table, at a show I had this all zipped up in a padded "beer proof" backpack, running from a 12v SLA.  I think whatever heat the UA-5 generates is pretty will insulated. I've always run my UA-5 that way... but I used to run non-phantom power Naks, and with a 9V Lion battery.  I suspect 12v generates a little more internal heat than 9V does, and phantom power conversion generates heat.  I wonder if all these little differences are enough to make a difference.  This particular UA-5 is "new to me", but I have no reason to doubt it.

Simple question.... is this a known problem?  I hadn't heard of it.   

[fozzy]

hrm, the SLA should be fairly stable even at high temperatures, much more so than nimh or lithium. 
fwiw i have run my UA5 in extremely hot environment and not had any issues, the JB3s I had on the otherhand saw numerous over heating problems.

[Roving Sign]

JB3 overheats are usually lockups and shutdowns...

Just curious - why do you guys run those things on 12V DC? The box specs 9V?

Seems like running the phantom on this box makes it much more battery intensive - is it possibly more practical to use a standalone phantom  supply?

[SmokinJoe]

I'm running it on 12V because a 12V SLA came with it when I bought the used UA-5 from the yard sale.  Sold by Doug Oade specifically for use with a UA-5.  Surpised me too, but I'm gonna trust Doug on that one.   Bottom line, the 12v works fine... but depending on the Voltage Regulators used, I can see that it might run hotter...

[dean]

I run 9v dvd batt all the time and have no overheat problems that I've identified as caused by the batt > ua5.  Mine's tucked nicely into my Lowepro Nova5 bag, but not tightly like you describe.  Twice at 10klf last summer I overheated, but I've attributed it to the jb3.  Conditions at the time were very hot - high 80's - mid 90's in glaring sun, around 2:00 pm, each time powering the HO's via phantom, two days in a row.  Other than that I've not had a problem with 9v dvd batt > ua5 with phantom power over a ridiculous number of recordings...

Hope that provides a point of reference and can be helpful.

[SmokinJoe]

I run 9v dvd batt all the time and have no overheat problems that I've identified as caused by the batt > ua5.  Mine's tucked nicely into my Lowepro Nova5 bag, but not tightly like you describe.  Twice at 10klf last summer I overheated, but I've attributed it to the jb3.  Conditions at the time were very hot - high 80's - mid 90's in glaring sun, around 2:00 pm, each time powering the HO's via phantom, two days in a row.  Other than that I've not had a problem with 9v dvd batt > ua5 with phantom power over a ridiculous number of recordings...

Hope that provides a point of reference and can be helpful.

I think overheated JB3's is "a known issue."

But so far no one has said they had the same drop out issue that I've had where one channel goes nuts level-wise.

I've got a 9V DVD battery that I used successfully before I got the 12V SLA... I'll try that next time and see what happens.

[tfrench]

I've got a 9V DVD battery that I used successfully before I got the 12V SLA... I'll try that next time and see what happens.

This is probably you best bet to determine the battery piece of the puzzle.  Try running the same set up originally mentioned to see if you have any problems.

Todd

[SmokinJoe]

I ran last night on 9V battery.  And the problem mystereously moved to the other channel.   Not a mystery really, almost surely I mixed up the left and right cables...  which is good actually... because process of elimination would indicate it's probably NOT the UA-5... now I suspect the mic or cable.  The plot thickens...

[anodyne33]

I ran last night on 9V battery.  And the problem mystereously moved to the other channel.   Not a mystery really, almost surely I mixed up the left and right cables...  which is good actually... because process of elimination would indicate it's probably NOT the UA-5... now I suspect the mic or cable.  The plot thickens...

I was just going to say that I had a similar issue for a while with a set of cables that I used to run. Crazy, random, intermittent noise that was driving me ape shit trying to figure it out. They looked fine at the connectors, so I suspect that there's a problem with the shielding or the insulation. As soon as I ditched the cables the problem was gone.

[SmokinJoe]

I figured out my problem is the mic, not the UA-5, or the cable.

Try different preamp, and a different cable, problem still exists... only thing left is the mic.

Edit: Mic is on it's way back to the factory for analysis.  I'll let you know how I make out.