Problem with non-speaking bass rubbon on a Magnepan

After 22 years it’s common for capacitors to give up. When they do, the sound that comes out can be weird in many ways. It depends on where in the circuit the capacitor is, what its current state is, etc. It could be a different component but 20+ year old caps are usually the culprit.

Your new Maggies are likely a tougher load than your previous speakers and pushed a marginal component past its limit. Or, it was going to happen with your old speakers anyway if you had played them for another 15 minutes.

2 Likes

:fireworks: :christmas_tree: :sparkler: :balloon: :sparkles: :fireworks: :tada::christmas_tree: :balloon: :sparkler: :sparkles: :fireworks: :christmas_tree: :sparkles: :sparkler: :balloon: :christmas_tree: :sparkles: :fireworks:

:loudspeaker: At least…
The problem I’m dealing with since 1 week was not about speakers, not about the amp, not even about cable…
The prb was an ill-plugged banana in the amp, towards panels.
I tried today to move and turn bananas a bit, and like a magic, the humming in the Magnepan stopped, and the sound bloomed full range from each panel.

:speaker: :musical_note: :sound: :notes: :loud_sound: :musical_note: :notes: :musical_score: :trumpet: :violin: :postal_horn: :musical_keyboard: :saxophone:

8 Likes

Now, that’s good news, bravo :clap: :fireworks: :notes:

1 Like

Yes it would be understandable. Before realizing noon that it was just a banana-prb, I talked with an expert hifi repairman in the morning. He told that my old hand-made amp was a piece of genius and that I should keep it alive by all means, because it will be difficult to overcome it. Unless with preamp&monoblocks costing more than 100k$
But actually this old amp seems in perfect health, even with demanding & low impedence 20.7.

2 Likes

And sometimes it’s just a marginal connection :slight_smile:

yes sthing like turning half a mm the banana in the plug of the amp…
And that difference is huge ^^
When I think my first reaction was to send back the panel to Magnepan, I am about to laugh (of me) ^^
I should have follow a methodical way of solving : checking all elements of the connection…
Actually, I plugged-in and plugged-out the amp output, but I first didn’t try to turn the banana to find the fitting position.

1 Like

Well this is a great ending! I’m glad for you. I find most of the time you just have to follow the signal path.

Btw - I don’t view the 20.7 as a fairly difficult load. They are pretty flat around 4 ohm across all frequencies. They are inefficient. I believe 86db. I think those numbers are pretty consistent across all Maggies.

I think all mechanical connections between components in a hi-fi system can benefit from occasional unplugging and replugging, especially those that can be rotated, like RCA jacks and banana plugs. Making fresh contact sometimes works wonders. Even seemingly dead batteries in remote controls can often be brought back to life by rotating the batteries in their compartment, establishing fresh connections with the remote’s contact points. Corrosion is an insidious bastard.

2 Likes

I read somewhere that the impedence is not so flat, and that it decreases to 2.5 ohms for some frequencies. My dealer said that the 20.7 are more demanding in the low register than my previous 3.5.
3.5 specifies 85db, and the 20.7 only 1 extra db , but 20.7 are much more efficient (not on paper but by ear-test).
My amp was at the 8 level with 3.5, now rather 6-7 level with 20.7.

With the trouble I knew since a week, I am now aware of the incredible importance of these small bananas.
So I think I will change them for another model which can secure a tighter plug in my amp.

1 Like

Here is a nice article. You are right on the dip. https://www.hifinews.com/content/magnepan-magneplanar-207-loudspeaker-lab-report

1 Like