Defective power board in Spires - what are my options?

MartinLogan Audio Owners Forum

Help Support MartinLogan Audio Owners Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

phips1702

Member
Joined
Jan 20, 2024
Messages
11
Reaction score
8
Location
Bad Dürkheim, Germany
Dear all,
I hope this is the right forum section: I have an issue with one of my ML Spires: the ESL panel is working, however, the bass driver remains silent (or more precisely, hums and plops in a low level noise). I have replaced the Icepower amp board with a new one, the issue remains. I exchanged the back panel with the power supply board and the amp board from the working speaker to the malfunctioning one and everything is fine - so I assume it is the "power board" (no clue if that is the correct term for it), which is the larger board of both, see attached image.
I can't see any blown or bloated capacitors, nor do I see anything like burns of electronic parts. Could it be a dry solder joint?
Any thoughts on what my options are? I contacted ML for a replacement (still waiting for answer), but maybe someone here knows another way to go or has maybe had the same issue.
Cheers,
Philipp
 

Attachments

  • IMG_3928 Mittel.jpeg
    IMG_3928 Mittel.jpeg
    137.9 KB
Dear all,
I hope this is the right forum section: I have an issue with one of my ML Spires: the ESL panel is working, however, the bass driver remains silent (or more precisely, hums and plops in a low level noise). I have replaced the Icepower amp board with a new one, the issue remains. I exchanged the back panel with the power supply board and the amp board from the working speaker to the malfunctioning one and everything is fine - so I assume it is the "power board" (no clue if that is the correct term for it), which is the larger board of both, see attached image.
I can't see any blown or bloated capacitors, nor do I see anything like burns of electronic parts. Could it be a dry solder joint?
Any thoughts on what my options are? I contacted ML for a replacement (still waiting for answer), but maybe someone here knows another way to go or has maybe had the same issue.
Cheers,
Philipp

Introduction:

I dismantle not Spire but ELS 9. ELS 9 is passive design and has two opposing woofers. Inside the ELS 9 cabinet is a crossover circuit, high voltage power supply circuit and audio transformer.

Body ( ignore perhaps inaccurate):

Inside Spire i imagine amplifier signal travels from speaker terminals first to crossover circuit. Crossover may include diodes, electrolytic capacitors, resistors, inductor copper coil.

Flowing from the crossover circuit, the signal is divided and subsequently flows to class D amp powering woofer and high voltage power supply. High voltage power supply includes integrated circuit and audio transformer.

Audio transformer change music signals to positive and negative voltages.

Conclusion:

First, one or both wires leading to the woofer perhaps loose or detached. And/or possible structural fault in the woofer.

The larger board, “power board” is the crossover circuit. Interchange only crossover board. From left speaker to right speaker. And vice versa. If the problem, hum and pop, changes sides you will know the fault is in the crossover board.

One or greater number crossover components detached from circuit or not functioning as design intended.
 
Introduction:

I dismantle not Spire but ELS 9. ELS 9 is passive design and has two opposing woofers. Inside the ELS 9 cabinet is a crossover circuit, high voltage power supply circuit and audio transformer.

Body ( ignore perhaps inaccurate):

Inside Spire i imagine amplifier signal travels from speaker terminals first to crossover circuit. Crossover may include diodes, electrolytic capacitors, resistors, inductor copper coil.

Flowing from the crossover circuit, the signal is divided and subsequently flows to class D amp powering woofer and high voltage power supply. High voltage power supply includes integrated circuit and audio transformer.

Audio transformer change music signals to positive and negative voltages.

Conclusion:

First, one or both wires leading to the woofer perhaps loose or detached. And/or possible structural fault in the woofer.

The larger board, “power board” is the crossover circuit. Interchange only crossover board. From left speaker to right speaker. And vice versa. If the problem, hum and pop, changes sides you will know the fault is in the crossover board.

One or greater number crossover components detached from circuit or not functioning as design intended.
Thanks for you reply - good to know that it is the crossover board, I was indeed struggling to find the exact type.
In terms of potential loose wires - as I wrote above, I already exchanged the stack of the crossover board and the amp board with the one from the functional speaker and everything is fine - and I also exchanged the amp board with a new one, so it has to be the crossover board. My question rather was: what are my options apart from asking ML for a replacement board :)
 
Seeing that the speaker was launched in 2008, I'd check ASAP to see if they still have that board. I'm not sure about their ability to supply parts that far back. I know they make panels for just about every speaker, but I've not heard that they can still produce other parts that old. I think they have a set number of parts in reserve for older models, and when they are gone they are gone.
 
Hum may signify that fault is in power supply rather than crossover.

i am most probably incorrect in my identification of problem area, namely crossover circuit.

Sorry for confusion.
 

Latest posts

Back
Top