[jvh]

I purchased an Ear+ form Mapletree Audio Design a few weeks back.

When the unit arrived after setting it up I plugged it into my BP-jr. It tripped the GFI circuit. I plugged it directly into the wall and the unit powered up. I also noticed the power switch did not have any affect. The unit was always on.

I spoke with Lloyd at Mapletree and he said maybe the switch was shorted. I bypassed the switch and it still tripped the GFI on my BP-jr.

I meter tested the AC socket on the amp, There was continuity between the center ground and one of the ourtside prongs.

Out of curiosity I removed the fuse and plugged the unit back in, It powered up with no fuse in place.

He even sent me a new fuse holder to replace before I sent the unit back. It also powered up with "no fuse holder" in place and wires separated.


The unit was sent back for repair.

I received the repaired unit today. I tested the unit plugged straight into the wall once unpackaged. The switch does work now and the unit does not operate when fuse is removed.

I installed the unit into my headphone system and plugged it into my BPT unit. Once I plugged in the BP-jr into the wall I heard a sizzling and smelled burt electronics. My BP-jr was toast!

I meter checked the unit and there is still continuity between hot and ground and neutral and ground at the AC connection at the amp. This is with "nothing" connected.

The unit does operate when plugged directly into the wall.

Could I have some opinions or even better could other Ear+ owners check their units AC plug on the amp for comparison.

Lloyd told me the unit and wiring checked out fine on his end when it arrived back for repair. And that he could not get it to power up with no fuse in place!


Thank you,
John

 

[flashbak]

You need to PM Nick Dangerous about this issue.

 

[Nick Dangerous]

Me? If you are volunteering me for Mapletree Tech Support, I'm afraid you're going to have to work for the Sugden call center.

Let's see... the switch works, A/C continuity looks OK, it will not run without the fuse, and works fine out of the wall socket. The only problem is that your BP-jr is dead.

If there was a short or too much current, the fuse should have blown. Plugged into the wall should have likewise tripped the circuit breaker... yet it functions as it should out of the wall, correct?

How does it sound?

 

[Joe Lau]

Quote:

Originally posted by jvh I purchased an Ear+ form Mapletree Audio Design a few weeks back. When the unit arrived after setting it up I plugged it into my BP-jr. It tripped the GFI circuit. I plugged it directly into the wall and the unit powered up. I also noticed the power switch did not have any affect. The unit was always on. I spoke with Lloyd at Mapletree and he said maybe the switch was shorted. I bypassed the switch and it still tripped the GFI on my BP-jr. I meter tested the AC socket on the amp, There was continuity between the center ground and one of the ourtside prongs. Out of curiosity I removed the fuse and plugged the unit back in, It powered up with no fuse in place. He even sent me a new fuse holder to replace before I sent the unit back. It also powered up with "no fuse holder" in place and wires separated. The unit was sent back for repair. I received the repaired unit today. I tested the unit plugged straight into the wall once unpackaged. The switch does work now and the unit does not operate when fuse is removed. I installed the unit into my headphone system and plugged it into my BPT unit. Once I plugged in the BP-jr into the wall I heard a sizzling and smelled burt electronics. My BP-jr was toast! I meter checked the unit and there is still continuity between hot and ground and neutral and ground at the AC connection at the amp. This is with "nothing" connected. The unit does operate when plugged directly into the wall. Could I have some opinions or even better could other Ear+ owners check their units AC plug on the amp for comparison. Lloyd told me the unit and wiring checked out fine on his end when it arrived back for repair. And that he could not get it to power up with no fuse in place! Thank you, John

It seem to be leakage in Power transformers. May be Primary wiring broken and leakage to chassis but I wondewr why
it don't trick the earl leakage breaker when you direct plug to wall ?

Ground should be isolated to Fire and nature. At Least a very very high resistance. It is abnormal if it can measure but a simply multi meter.

 

[Wodgy]

Just a suggestion, but the BPT JR only can handle 2.5 amps of current draw. You might want to check how many devices you have plugged into it. It's even possible that the Ear+ draws more current than that by itself... most amplifiers do, and the Ear+ is a small amplifier with a big transformer.

 

[jvh]

Quote:

How does it sound?

It sounds fine. It sounded fine when it would operate with no fuse in place before sending it back for repair also.

Quote:

A/C continuity looks OK

One thing I was questioning. The continuity at the AC plug on the amp.

Why is there continuity between the hot and ground and neutral and ground prongs.

I thought the center ground was for protection and should not make a circuit unless there is a short?

Thanks,
John

 

[Wodgy]

Another thing to check, I guess, is that it's possible that one of the wires or components inside is touching, or close to touching, the chassis. I believe the chassis is connected to ground.

 

[AssafL]

This is the time to start disconnecting circuit sections and testing continuity to ground.

BTW, if I were you, I'd find the short and fix it. If you connect to an ungrounded socket and your neutral wire disconnects, you may have the 110V single ended on your headphone ground (not as much fun, as, say, Brahms or Aimee Mann, on your headphones).

I say this is important because I rent an old apartment. Only about a third of the outlets have a ground receptacle, and about half of those are actually connected to ground.

 

[jvh]

Quote:

If you connect to an ungrounded socket and your neutral wire disconnects, you may have the 110V single ended on your headphone ground...

My headphone system is connected to a dedicated circuit with a secure ground.

John

 

[Possum]

I agree with Wodgy. When I sent the Cadbury Mk II amp I bought from MAD to a buyer, he had a problem where the power fuse was blown every time he turned on the switch. The problem was solved by checking the internals to disconnect whatever was accidentally shorted. Lloyd Peppard did say something about the problem in an e-mail:

"I don't know what happened in shipment but I hope you have pinned the problem down. Vibration can do a lot of damage (unless built to NASA specs)."

Maybe the way the MAD amps are assembled and wired internally leaves them more prone to this damage or accidental shorting.