What to look for in a bad active DI?

Re: What to look for in a bad active DI?

I have a half a dozen of these units and all have been working great. They may not be Countryman units but in my experience they are solid Di's. I would be interested to hear what caused the second failure.
 
Re: What to look for in a bad active DI?

Ben Lawrence said:
I have a half a dozen of these units and all have been working great. They may not be Countryman units but in my experience they are solid Di's. I would be interested to hear what caused the second failure.
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Ben, you beat me to it ;)

I don't think that a Countryman would survive a good lightning strike either ;)

That first fried unit saw something seriously bad to cook those resistors as it did. The mixer is lucky it survived IMHO.
 
Re: What to look for in a bad active DI?

Greg Cameron said:
It might be time to consider getting some better active DIs. I've never seen a failure like that on an active DI. In fact, I don't believe I've ever had one go bad in 15+ years. I've been using Whirlwind HotBoxes mostly for active units. Yes, the known name brand units are about 2x the price. But I doubt you'll have the failure rate with them that you are with those units.
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Oddly enough, I've had a Countryman go south on me, but they have a great warranty/service policy,and it was repaired for free.

I have had a Hot Box on the bench in the last couple of years, and it was a simple opamp swap to fix it.

The OP with the mystery failure in the second DI, as someone else suggested, replacing the opamp is a likely scenario.

The other one...may or may not recover.

Best regards,

John
 
Re: What to look for in a bad active DI?

If the battery is dead or missing, and you press the ground lift, it won't work right (possibly at all)

You probably knew that (but I didn't, until a battery went (mostly) dead on me - signal didn't go away, just sounded like s**t)
 
Re: What to look for in a bad active DI?

Ben Lawrence said:
I was under the impression you could run these off of a 9v or phantom power.
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Same here. Been busy and haven't had time to check it out yet, but I know the battery is not in the unit that was last working, and I've always run it off phantom. Can't remember if I took the battery out when it quit working or never replaced it after it died, but I know I always ran them with phantom on. I do remember having to flip the ground lift on several different occasions and I don't remember it causing any problems.
 
Re: What to look for in a bad active DI?

Ben Lawrence said:
I was under the impression you could run these off of a 9v or phantom power.
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Countryman FET85 must have a good battery or NO battery. A dead or dying battery will keep the unit from working properly or at all.

Carl Countryman says "Don't buy cheap mic cables and don't leave dead batteries in my DIs."
 
Re: What to look for in a bad active DI?

Hmm. That's interesting. I don't know if I pulled the battery out of mine before it had stopped working or after. I don't think I would have pulled the battery out before the unit went dead on me, and I never would have thought to test it without a battery at all installed. Maybe these boxes work in the same manner like those Countryman boxes. I'll have to test it like it is now with no battery in it, assuming I didn't do that before already.
 
Re: What to look for in a bad active DI?

I wouldn't waste too much time on theory's based on how some other DI works (or rather doesn't work). Prudent Di design should ignore battery status if phantom power is available. The last one i designed (decades ago) even ignored the power switch. If phantom power said "let's go", it would go... :-)

JR
 
Re: What to look for in a bad active DI?

John Roberts said:
I wouldn't waste too much time on theory's based on how some other DI works (or rather doesn't work). Prudent Di design should ignore battery status if phantom power is available. The last one i designed (decades ago) even ignored the power switch. If phantom power said "let's go", it would go... :-)

JR
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John,

Did you include a lightning strike load dump circuit in your DI design? ;)
 
Re: What to look for in a bad active DI?

Scott Bolt said:
John,

Did you include a lightning strike load dump circuit in your DI design? ;)
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No my design spec was mostly to protect products from the Peavey customers, not from acts of god. :-)

While there are plenty of opportunities for man caused smoke release with shoddy distro, miswired outlets, and whatever....

Ironically real grounds must pass tens of amps. Ground lifts don't make much sense in the context of human safety.

JR
 
Re: What to look for in a bad active DI?

Tim McCulloch said:
Countryman FET85 must have a good battery or NO battery. A dead or dying battery will keep the unit from working properly or at all.

Carl Countryman says "Don't buy cheap mic cables and don't leave dead batteries in my DIs."
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Yep. I have never installed a battery on the several Countryman FET85's or even the Peavey EDB's I have had for more than 20 years and still use today. Always phantom powered and never a single problem with any of them. I have not tried the "Lightning Strike" test yet though.
 
Not a DI, but someone just gave me a battery powered guitar amp called the crate taxi and said it wasn't working. I opened it up and there was a ups style battery with the sides bulging. I removed the battery and the amp works fine when powered externally.
 
Well, had a gig this weekend and borrowed a DI to use if i needed it. Tried my EWI DI that wasnt fried with no battery in it and it worked fine. Used it for 6 hours Saturday with no problems... go figure. Now maybe I can fix the toasted parts in the other and it'll work too.

Sent from my DROID RAZR 2
 
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