Magnepans 1.6 no sound

[waterlelies]

I have these Magnepans already several years in use, without problems.
Recently my JVC AX-Z711 has been revised and nog the Magnepans do not work anymore.
Nothing has changed to them. Fusies are ok.
Also with a Luxman700 they do not work. An other pair of speakers (B&W), work very
well with both the JVC and the Luxman.
What could be the reason?
Regards.

 

[DonH50]

Double check the cables and all connections with the integrated amp turned off. If you have an ohm meter, or know someone who does, you can see if an internal connection is broken inside the Maggies. It is strange that both speakers would have died at the same time, however, making me wonder if something else happened that might have damaged them? What exactly was revised in the JVC? Could something else have happened while the speakers were connected and amp on? Any loud pops or sounds? How loudly do you play them?

 

[waterlelies]

Double check the cables and all connections with the integrated amp turned off. If you have an ohm meter, or know someone who does, you can see if an internal connection is broken inside the Maggies. It is strange that both speakers would have died at the same time, however, making me wonder if something else happened that might have damaged them? What exactly was revised in the JVC? Could something else have happened while the speakers were connected and amp on? Any loud pops or sounds? How loudly do you play them?

The JVC got a new trafo as it did not start up, und the pre-amplifier has been checked, and the biass has been adjusted.
Another set of speakers (B&W) works well with he JVC along the same cables.
I also installed my old Luxman, with which the Maggies do not respond either.

 

[waterlelies]

Together with a friend , a technician, we have unmantled one of the Maggies.
Contacts were corroded and the aluminium strips of the alustrips did not react.
I have sent foto’s of the situation to the Dutch importer, who concluded that the speaker was impossible to repair.
Altough we did not check the other speaker, we assumed, that that has the same problem.
It looks like the end of my speakers, which accompagnied me for very many years!

 

[DonH50]

Together with a friend , a technician, we have unmantled one of the Maggies.
Contacts were corroded and the aluminium strips of the alustrips did not react.
I have sent foto’s of the situation to the Dutch importer, who concluded that the speaker was impossible to repair.
Altough we did not check the other speaker, we assumed, that that has the same problem.
It looks like the end of my speakers, which accompagnied me for very many years!

Magnepan will generally rebuild speakers for fairly modest cost. Shipping may be expensive if you are overseas, however. But I would contact Magnepan and see what they say.

 

[Gregadd]

Did you defeat rue Doses? That is the only problem I ever had. Be honest, we don't judge. Make sure they are not blown.

 

[DonH50]

Did you defeat rue Doses? That is the only problem I ever had. Be honest, we don't judge. Make sure they are not blown.

Check the fuses? He said he did that in his first post.

Over time the foil traces tend to degrade and eventually open, my guess is that's what happened here. Though back when I was repairing them I did find bad solder joints inside at times.

 

[Gregadd]

Yeah Don I saw rhat. I would replace rem anyway. Wrapping the fuses in tin foil was a popular tweak. You could blow rue tweeters.
My MD1 was purchased in the late '70's. They have been on loan to non-audiophiles. They still work. If grandpa still working so, should they.
Cold solder in both speakers?

 

[Alrainbow]

may I ask how connectors ar made from alum to copper or lugs used ?
I say this as my IRS have about 100 drivers alum trace
they used a Rivet also some solder on rivets
one could try to mash the rivets or heat the joint up
I did this on a few tweeters over the years
I own a pair of Maggie’s 3.6r
so far all is ok

 

[DonH50]

Yeah Don I saw rhat. I would replace rem anyway. Wrapping the fuses in tin foil was a popular tweak. You could blow rue tweeters.
My MD1 was purchased in the late '70's. They have been on loan to non-audiophiles. They still work. If grandpa still working so, should they.
Cold solder in both speakers?

Good advice. Unless the fuse was measured good it is suspect, and sometimes even then.

I loved the people who wrapped the fuses in foil, or bypassed with the wire, as it generated a fair amount of repair business for the shop I worked.

I have seen blown ribbons in both sides, and blown diaphragms, when they were overdriven (played too loudly). But from age, I rarely if ever saw both sides fail at once; usually, one side failed, and when I inspected the other side (we always asked they be returned as pairs) there signs of wear in the other as well. Magnepan always replaced tweeters, and panels, as pairs. You got me on the solder joints; yes, it would be almost unheard of for the failures to be due to bad solder joints in both speakers at the same time.

 

[DonH50]

may I ask how connectors ar made from alum to copper or lugs used ?
I say this as my IRS have about 100 drivers alum trace
they used a Rivet also some solder on rivets
one could try to mash the rivets or heat the joint up
I did this on a few tweeters over the years
I own a pair of Maggie’s 3.6r
so far all is ok

Infinity's EMIT and EMIM drivers were a mess for a while; I was constantly having to touch up the connections when they cracked and opened under stress. Al driver strips to brass (IIRC) eyelets ("rivets") soldered to wires provided several points of failure. At the time they authorized the shop I worked to do the repairs since they got to be so common and shipping and waiting was unacceptable to some (most?) customers for what was a quick repair job. The big caveat was, if I messed up or slipped with the iron and ruined the membrane, they would charge me (the store) for a new driver. I got real good real quick.

 

[Alrainbow]

lol soo nice of them.
when a mid died it was the rivet eyelet front to back
always was lol.
I tried to mash it but the issue was the foil has severed under the eyelet
so I tried a epoxy used to conduct like we use on
car defroster traces
This too was a failure
I did find a way though removing the rivet and putting a new one back together a tiny but bigger
what really caused this was over driving the mids in lower freq making them move more then they should

so did you get own an irs 3 ?
mine are this and were sent back to them for an upgrade to irs v.
Real ones have a brass placard on the back
Almost all I’ve ever Seen are not v,s
this is ok anyway
I had a conversation. With the man who made the woofer amps. he told me some good stories
since I’ve rebuilt the amps caps completely
magnets too.

 

[waterlelies]

Thanks for you comments, although it is not always easy to understand, due to many “expert” terms.
The situation is now as follows: I checked the second Maggie.
Saw no specific damage or corrosion.
What I did is carefully remove the screw which hold the small wires of the left wirepanel, clean the end of the thin wires , sothat they were blanc, and ….. I heard sound! I did not do anything with the other segment with the alu-strips. But it looks like this speaker is now OK, although I still have to listen carefully tomorrow!
How this small “defect” could happen is unclear to me.
Then I reviewed the other speaker, of which I have sent the photos. I did the same exercise, and.. also sound!
The only thing there is that the alu-strips - when I messure them with an Ohmmeter - give a big resistance, so I think this part is still defect .
So that I do not know how to solve.
Strange. This case of bad contacts wire/connector must in my opinion
happen more often, but nobody mentioned that.
Even the Dutch importer concluded that the Maggies had to be replaced!

Greetings from the Netherlands,

Fre.d



.

 

[Alrainbow]

This is a possible dissimilar metal oxidation
Put simple almost all metals get effected by oxygen
glad you pushed through. Think car battery posts while not the same is still like it

Share some pics for us. your now an honorary DIY member

 

[Alrainbow]

T

 

[DonH50]

The conductors should have fairly high resistance but what do you measure?

 

[waterlelies]

Herewith some photos of the left speaker, of which only the "wire" part gives sound.
The ends of the alu-strips are not connected officially, but when I connect them manually, the "alu"-part does not give sound. If I measure the resistance between the two ends of the alu-strip, I measure an endless resistance, so it looks like there is some interruption in the loop of the alu-strips.
Can't this complete interior not be renewed or does that not make sense?
Greetings,
Fre.d

 

[Alrainbow]

Wow bro high humidity location. Are you near a lake or salt water ?
the alum trace looks welded to the tab where screws are
so test for residence on the tab close to the traces

 

[Alrainbow]

Also mark what has resistance
Some are wires not traces
one thing to try is one connected to alum trace near tabs and other at various places following the trace around
it’s ok to scrape lightly to expose alum
my guess is it’s open looks bad

 

[DonH50]

I agree with @Alrainbow that is serious corrosion. The bass section is wire on the diaphragm, the tweeter is Al foil traces. The foil/connector contacts can be an issue over time (dissimilar materials tend to react with each other and become open) but it does look like the foil traces are bad. I have had little success is trying to clean the foil itself; the oxide is hard, the foil is soft, and very thin so it is hard to clean the foil without ripping it.

You could try very carefully removing the screws without breaking the wires or foil traces, cleaning or burnishing screws and contacts/connectors (without touching the foil attachment points on the connectors), treating them with an anticorrosion spray or liquid, then reconnecting to see if that is the problem.

Magnepan will rebuild these speakers and that is probably your best option unless you are, or know, a really good tech familiar with planar and ribbon speaker repair.