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ZONER

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Well, I had a major malfunction and cooked the crossovers in my Quests. I had recently replaced the stats and woofers. Now they are like a classic car with no engine! Martin Logan no longer has the parts to replace or repair them. Does anyone have old Quest crossovers that need a home, or know where I might send them to be rebuilt. If I hadn't recently invested in them I would just upgrade. I might have to anyway! Any info would be appreciated. Thanks Zoner.
 

JonFo

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If you can not obtain parts to replace the passives, I highly recommend going full-active. The results of that on these older models are a huge improvement.
A DriveRack Venu360 is under $1K, and several of us can assist with setup.
With fresh panels and woofers, well worth the effort to get them going again.
 

Brandon Hartwick

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Can you go into a bit more detail? What exactly happened to kill the passive components in the crossover?

If it is in fact the caps and resistors in the crossover that's an easy fix.
 

ZONER

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Brian at ML said I drove them too hard or it my have been my amp. So I bought new amps, PS Audio Stellar M1200 monos hoping the crossovers could be repaired. The technician at Midwest Speaker Repair sent me this message yesterday. These are not looking good, main problem is the PC Boards have massive damage as well and part of the amplified section that goes to the electrostatic tweeter has damage too, that I have know way to test to see if there are any other parts bad besides the obvious burnt ones. I have been in contact with ML and they just got back to me yesterday with concerns on how bad these are, too many issues. Also, do you know if the tweeters and woofers work, because this much damage usually takes out the woofers and tweeters too. Let me know your thoughts. it doesn't look like it would be a good idea to attempt to repair.

JonFo, I'm not familiar with a DriveRack Venu360. Is that some kind of external crossover? I will do some research.

Thank you both.
 

Big Dog RJ

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Driving Stats too hard, mmm... this may be the very reason why Quad uses protection circuitry in all their stats starting from the old ESL 63's. They were very limited though, great imaging and soundstage depth, probably the most effective in stat design when it came to soundstage, due to their unique design.

If driving ML stats too hard, wouldn't there be some sort of distortion rating kicking in? The thing with stats is they have zero distortion, so when it plays smoothly, we tend to crank things up! Stats are not meant for this or least not the previous series. With the newer series, they're well capable of large dynamic swings and transient peaks that none of the previous versions could handle. So they've come a long way...

Nonetheless, stats aren't for blasting. They're meant for fine music reproduction. If you really wanted to blast that much, you're better off with dynamic driver types.

How loud were you actually going?
Even then, I'm thinking at least either the amplifier or speakers should have distorted... I think most probably your electrical grid had a surge that was not noticeable whiles playing too loud. All of a sudden this caused the electronics to damage... this does happen.

I've had two instances like this; in fact one of the speakers were Quads! There was a surge and it fried the top half of the stat panel (3 panels to be exact) and shut down one of the EHT trannys. The repair was dam expensive but I had to do it, in order to make them re-sellable. The other speakers were Wilson's. The previous owner went through a lighting surge in the house... fried everything on at the time, including his fridge. It burnt out the electronics in both X-over boards. Of course Wilson were willing to repair it but at a hefty cost. So the owner just got some third party to touch it up. I bought that very pair and got it fully redone upto spec and finally sold them off to a person who always wanted Wilson's. He still has them and uses Lamm Audio gear to drive them, absolutely tops!

So yes, these things can be repaired and modded to arrive at decent spec. Perhaps not the original spec but very close, sometimes to such great efforts where the modded versions surpass the original. Been there myself and done it to great success.

The question is, how far are you willing to spend? Are these Quests of sentimental value to you? And are they worth the trouble?
Only you would be able to determine that. You can get all the best advice possible but at the end of the day, that final decision is yours!

Cheers and all the best.
RJ
 

JonFo

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Wow, it almost sounds like they were connected to line voltage. It takes a ton of voltage and amperage to deliver the damage reported.
Maybe a wiring short on the high-voltage board?

I'm guessing the step-up transformer is also cooked, so you'll need to replace that.

From all of this, maybe your best bet is to sell the relatively new panels and woofers (if working) to another Quest owner, and write-off the rest.


JonFo, I'm not familiar with a DriveRack Venu360. Is that some kind of external crossover? I will do some research.
Yes, it is an external, active crossover, or more accurately, a 'speaker processor'. It has many useful features that can be used to implement a fully active ESL two-way (or three-way with a sub) crossover setup. dbx DriveRack VENU360 Loudspeaker Management Processor

It has a learning curve as any active XO would. But the Software is fairly well done. It also works best with balanced sources; otherwise, some RCA -> XLR adapter cables and careful tweaks to the input levels are required.
 

ZONER

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Ya, the inductors we literally melted, caps blown out. The speakers still worked OK. Amazingly!
So know I'm thinking Summit X or Montis, or find an old pair of Quest or Quest Z's just for the crossovers.
 

Big Dog RJ

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That's what I was thinking, it's definitely a power surge along the AC mains somewhere at one point along the grid... there's no way you can damaged a stat panel like that during domestic hifi playback. If it was so very loud, first of all your hearing would damage, it would hurt your ears and distortion would set in.

The other thing is, it's not that easy to over-drive or distort ML stats, they're built to very high tolerances. Unless it were rock concert levels on playback, which again is not attainable at domestics settings.

Once you do get moving forwards, my best advice is to rewire your AC mains line as a dedicated line just for the audio system. Have this line directly wired to the AC mains board and one in house outlet or number of outlets you want to use. It's always best to keep things simple and use just one dedicated AC line with a power board having several outlets of your choice.

Also remember to include a separate CB switch on this line, so that in the event of any future power surges, brown-outs or black-outs, this CB will trip, protecting your audio gear!

I'm assuming that you've not done this, otherwise it would have tripped in the first place. If you've already done this basic AC mains line setup then good on you! In which case, how the heck did this happen...?

Hopefully, you'll get this all sorted out and have a decent pair of stats once again. Yes, the Montis or Summits would be the best in terms of real upgrades. You will really like any of these hybrids, outstanding stats! Just make sure the rest of your gear is up to par.

Best, RJ
 

ZONER

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I do have dedicated circuits for each component, but no surge protection, lesson learned. I have an Ayon cd 1sx integrated pre-amp and I just ordered PS Audio Stellar M1200 monos, because I don't want to use my old amp when I get new speakers. Once bitten, twice shy! So, I should be good with whatever ML speakers I end up with. Also just posted " Wanted ML Quest or Quest Z Crossovers" in the classified. Maybe I'll get a bite before I pull the trigger on and upgrade.

Thanks,

Zoner
 

Brandon Hartwick

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If you get the crossovers and power supplies back please post up some pics of the damage, I'm very curious to see what was destroyed.

The crossover section is mostly point to point wiring so it's relatively easy to fix, but the step up transformer section uses printed circuit boards and many small resistors so that could be challenging.
 

Brandon Hartwick

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You sir, had a serious power issue. This looks like a power surge, a bad amplifier doesn't usually cause damage like this.

If you're going to repair these you need both the ESL power supply and the crossover. The crossover components can be replaced and Martin Logan should be able to provide you with a diagram for everything including the power supply. The power supply parts can likely be purchased from an electronics parts supplier.

Before you go any farther you need to check the ESL panels and woofers to make sure they're not fried. The woofers can be checked with a volt meter but I'm not sure how the panels should measure. Don't purchase anything until you verify the speaker components are still good.
 

Leporello

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and part of the amplified section that goes to the electrostatic tweeter has damage too,
If it has an amplified section that goes to the electrostatic tweeter it's not "passive". Otherwise, a crossover is just inductors and caps and maybe resistors. Worst case you, or someone, could build a new crossover on a new board--winding your own oxygen free copper coils (per the ML specs). Any competent tech should be able to do this, certainly anyone who calls themselves "Midwest Speaker Repair". I fail to see how this is not repairable. More like a car without tires than without an engine.

Of course, you could go the biamping and external crossover route. That would be a good option, potentially resulting in a better speaker. But at what cost?
 

audioxcel

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I have to wonder if components, boards and transformers from any other 15" stator models can be used in the Quests. It seems like the electrical requirements would be the same for all 15" stators.
 

Brandon Hartwick

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I have to wonder if components, boards and transformers from any other 15" stator models can be used in the Quests. It seems like the electrical requirements would be the same for all 15" stators.
They very well could be, with some minor changes. Martin Logan is usually pretty good about supplying electrical schematics, that's where I'd be starting.
 

ZONER

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Guys you're giving me a little hope! Believe it or not the speakers worked. The stats worked but lost the highs and the woofers worked fine.
ML has the power supplies at about $500 each. I just don't know where to send them to be rebuilt. The $64,000 question is for how much and is it worth it. Midwest Speaker Repair doesn't think they are worth repairing.
 

ZONER

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BTW, I have the schematics for Quest and Quest Z. But I have no idea what to do with them.
 

Brandon Hartwick

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Guys you're giving me a little hope! Believe it or not the speakers worked. The stats worked but lost the highs and the woofers worked fine.
ML has the power supplies at about $500 each. I just don't know where to send them to be rebuilt. The $64,000 question is for how much and is it worth it. Midwest Speaker Repair doesn't think they are worth repairing.
It really depends what's wrong with them, the electrolytic capacitors and resistors are easy, the step up transformers could be hard to find, assuming they're blown as well.

You really need to figure out exactly what is broken and what is not. From the pics there is definitely damage on at least 1 power supply board, a resistor is clearly cooked. One crossover has 2 electrolytic caps that have exploded and it looks like both crossovers have melted have an melted the inductors closest to the bottom.

I'm going to study the pics a little more, this should be fixable, especially if ML will sell you new power supplies.
 
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