Mapletree Ear+ problem? Help Please
post-177624
Thread Starter
Post #1 of 10

jvh

Head-Fier
Joined
Jul 24, 2002
Messages
63
Reaction score
10
Joined
Jul 24, 2002
Posts
63
Likes
10
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
 
     Share This Post       
post-177681
Post #3 of 10

Nick Dangerous

Mr. Tuberrific
Joined
Nov 19, 2001
Messages
2,623
Reaction score
27
Joined
Nov 19, 2001
Posts
2,623
Likes
27
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?
 
     Share This Post       
post-177693
Post #4 of 10

Joe Lau

Antique Sound Lab
Joined
Nov 23, 2001
Messages
443
Reaction score
10
Joined
Nov 23, 2001
Posts
443
Likes
10
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.
 
     Share This Post       
post-177694
Post #5 of 10

Wodgy

Headphoneus Supremus
Joined
Feb 24, 2002
Messages
4,657
Reaction score
12
Joined
Feb 24, 2002
Posts
4,657
Likes
12
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.
 
     Share This Post       
post-177695
Post #6 of 10

jvh

Head-Fier
Joined
Jul 24, 2002
Messages
63
Reaction score
10
Joined
Jul 24, 2002
Posts
63
Likes
10
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
 
     Share This Post       
post-177697
Post #7 of 10

Wodgy

Headphoneus Supremus
Joined
Feb 24, 2002
Messages
4,657
Reaction score
12
Joined
Feb 24, 2002
Posts
4,657
Likes
12
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.
 
     Share This Post       
post-177742
Post #8 of 10

AssafL

Head-Fier
Joined
Jun 21, 2002
Messages
61
Reaction score
0
Joined
Jun 21, 2002
Posts
61
Likes
0
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.
 
     Share This Post       
post-177777
Post #9 of 10

jvh

Head-Fier
Joined
Jul 24, 2002
Messages
63
Reaction score
10
Joined
Jul 24, 2002
Posts
63
Likes
10
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
 
     Share This Post       
post-178077
Post #10 of 10

Possum

500+ Head-Fier
Joined
Jun 22, 2001
Messages
746
Reaction score
10
Joined
Jun 22, 2001
Posts
746
Likes
10
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.
 
     Share This Post       

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top