ML Sequel (1) what happened with the cascade ?

Hello my name is Rob, i life in the Netherlands, and i am since 10 years the owner of ML sequel (1) speakers.

After some friends did upgrades their systems, i could not leave behind.
I wanted to upgrade my system with some real good speakers (which together with room accoustic are the weakest link in the audio system).
On the internet i found the ML sequels and could test them on location.
Bam ! Greatest speakers i have ever heard (tested with some good recorded jazz music).
Bought the speakers, and now everyone who listens to them wants to have them.

But, since a while the panels became more quit (bass got to loud), and got worse.
They told me the costs to replace the panels were 1000 Euro (~ 1100 dollar) for each pannel.
The speakers are from 1987 and to spend 2000 euro's for 30 year old speakers (the electronics and the woofer are also that age) is to much for me.

So i did clean the panels (one by one so i could compare the result).
Well, they became much clearer, also in sound
.... Then i found out that the rubber of the woofers were (almost complete) loose from the chassis.
Ok fixed that too.

Then saw some modifications made in the electronic circuit which were certainly not made during assembly.
(ie 10 ohms parallel to the inputs of the woofer).
But most "shocking" was the fact that the highvoltage part of the panel was connected at the fifth stage of the cascade instead of the twelfth (last) stage (i think 500V instead of 1200V could not measure).

And now?
I think i will remove the 10ohms, and test the diodes and capacitors of the cascade (maybe replacing the last stages components) and connect the HV of the panels to the twelfth stage again (ofcourse with high ohm resistors).

Has anybody have an idea why this was done?

Hello Rob, something is not right, I would suggest you call ML's service department right away, they are very helpful and can talk you through anything you need to do, you sound like you understand most the technical things, please do not touch anything until you speak with them, Craig

Hello Stuwee,

Thanks for the respons, yes i will contact ML's service because this is really strange.
I will give a report of the results.
Btw; maybe we could use the timemachine to go back in time to check what happened to my poor ML's

Greetings,
Rob

Hello Craig,

I got the instructions to test the HV stage from ML service.
A 1000Mohm (1Gig) serie resistance is needed to measure the HV (otherwise the little capacitors will drain and a faulty reading will be made).
This is not a standard resistor (from brand Ohmite) i have to order one.

Greetings,
Rob

Hello Rob, great! Although I don't know a thing about what you just said, sounds like Greek to me lol! Anyway, when I had trouble with my Sequels, I was fortunate to have a roommate that was an electrical engineer, he spoke that language, knew just what to do, and was well again.

I wonder what your serial #'s are, mine didn't show up on the tracker 'sticky' thread here on the MLforums, in fact Jim Powers worked the production line back then and built my crossovers, emailed me about that. There is something very special about the first curvelinear Sequels, built by the best by their own hands. Please make sure you get the right replacements as close to the originals as you can. There's magic in those circuits Rob!!

Craig