rhythmic panel ticking - help

[Bruce Weiland]

Hi guys,

I obviously need help.

One of my Prodigy panels has a continuous ticking sound when charged whether or not an amp is connected. The other panel, on the same AC source, is silent.

I have changed to a different AC source. However have the same ticking sound.

Is it likely that a capacitor in the static charge circuit is failing or has failed?

Please help. I miss my music.

Thanks in advance for any guidance.

Bruce

 

[Bruce Weiland]

I have a further thought. Is it likely that the circuit that powers up the panel bias when an audio signal is present has a failing component and is quickly powering on and off?

 

[Gordon Gray]

Bruce,

Probably the power supply. Call ML service.

Gordon

 

[Bruce Weiland]

OK Thanks Gordon

 

[JonFo]

I have a further thought. Is it likely that the circuit that powers up the panel bias when an audio signal is present has a failing component and is quickly powering on and off?

It's more likely in the bias supply itself, as my Monolith III's, which have no audio-signal detector circuit, also occasionally will do the ticking sound when first powered up. In my case, the ticking stops after a few minutes.

Not surprising that a 25+ year old capacitor is beginning to fail. So I'll need to dig out the bias supply board and have it refurbished one of these days. Might do a step-up transformer upgrade at the same time.

So yes, contact ML and see what they offer in terms of service for that Prodigy.

 

[Bruce Weiland]

Thanks Jonathan. I have an email request into them now.

 

[Bruce Weiland]

Solved it!

Oh the sweet sounds of a Prodigy panel with all of the passive crossover components bypassed, and externally crossover with a digital active crossover. And powered by 100 W of triode 6SN7's and EL 34’s.

I have to admit there were a couple of Homer Simpson doh moments.

I have to give props to ML service/support. I emailed Sunday to an individual who is no longer there. And Scott got back to me by 9:30 AM on Monday.

First thought. I thought I would have to pull the rear drawers and switch the power supplies. Really big job, requires moving speakers, etc. I currently have only one functioning hand.

Scott suggested that or just transfer the panels whichever was easiest for me. Big DOH!

Second big DOH that I left out. The panels have been slipping for the last four years. The left panel is down by about 3/4 of an inch. The right panel was further and recently seem to go even more.

After I remove the right panel I saw how easy it was to move it back up in the frame. I did that. I reinstalled it. Now the ticking was much faster. And when I jiggled the connection I could cause it to vary in speed. So obviously the panel wire connection.

I took it off again. Disassemble a little bit further and found that the solder joint to the front stator was all about nonexistent.

I re-soldered the joint. Installed the panel on the speaker again. And everything is wonderful.

Thanks Gordon and Jonathan for chiming in.

Bruce

 

[JonFo]

Great to hear Bruce, glad you got it resolved and thanks for sharing the cause and the fix.

We all need to remember to double-check the wiring to the panel, as that can be a weak spot that has manifested itself in several recent incidents reported on the site.
Matter of fact, will double check the wiring on my speaker with the occasional tick, I might get lucky and it's a simple tightening of wires in the top connector block (Monoliths have an intermediate connector block between the bias board and the panel.)

 

[Bruce Weiland]

Final thought on ticking-popping-arching caused by panel slippage

Guys and gals.

Once I figured out the cause of the problem and fixed. ML sent me a pdf of their fix, copyright 2008. They had obviously been aware of the problem with the four models listed in the pdf , Ascent, Ascent i, Odyssey, and Prodigy, long before I was. And had already engineered a simple fix.



I knew about this thread but had no idea ML had solved it for us too.

http://www.martinloganowners.com/forum/showthread.php?3433-ESL-Panel-Slippage&highlight=panel+slip

I tried to attached ML's 5 page pdf, but it exceeds the size limit.

Email ML and ask for Stat_Panel_Clip_Service_Document_rev051508.pdf

Bruce