Got My Replacement Amp from AV123.... - Page 5

Originally Posted by deez

Please let us know.

Originally Posted by Lhasa-lover

That's interesting. I wonder if there is a connection between those of us who have orginal, working amps, whose subs seem to be pushing a LOT of air and those that have had bad amps. Perhaps their subs are not pushing nearly as hard as ours but as they have no frame of reference, don't realize it.

Originally Posted by stereojunkie

do you have any pics of the driver that you can post. I do not believe I have seen the guts behind this beast. Glad to hear you are rocking again.

Originally Posted by Lhasa-lover

The driver has no markings whatsoever. Not a number, not a stamp, not a tag, no label, nothing. Must be custom made or OEM'd.

Originally Posted by James W. Johnson

This thread needs to be locked.

Sure , me and Klipsch went OT but you guys are rediculous.

Moderator, lock this thread please, thanks.

Originally Posted by James W. Johnson

This thread needs to be locked.

Sure , me and Klipsch went OT but you guys are rediculous.

Moderator, lock this thread please, thanks.

Originally Posted by graphicguy

Please no.......no locking. At least with a couple of posters out of the way who added little, this is a good place to come and see the experiences people are having. Usually, it's done in a rational manner, too.

Cats, grill cover, etc discussions don't bother me.

MLS "hinted" that he was going to do something with the warranty. I'd like to find out what that might be.

Plus, I expect the new retrofitted MFWs should be hitting the market in the next few weeks. It might be good to keep on top of that, too.

Originally Posted by mdaudioguy

Yes, it will be interesting to hear what people think of their MFWs with new amps. I'm especially interested to hear from those who have an older model that also pick up a newer "fixed" model. I've been considering adding a second one and would hope (or expect) that the performance would be identical to earlier models. It is also interesting to hear, however, that future models might not be using the same driver (as suggested by craigsub), although I was unclear how he was in a position to know that.

Originally Posted by graphicguy

That's a good question about the driver. The current Eminence driver is a great one. And, we all have to admit, a Mark Seaton designed sub isn't something you take lightly.

Amp issues aside (which I know is hard to do), I would be curious how the "new" amps affect performance, if at all.

There's a person over at "tweakcity" (Lance) who actually took apart the amp. He qualified his findings by stating he wasn't familiar with Class D. I'm not an EE, so much of what he said went over my head.

But, taking a look at some of the wire winds on some components (inductors), were sloppy and their coating literally "flaked off, it tracks with what MLS mentioned. That is, the amp supplier started using some inferior/not-to-spec parts. As a result, he also said that the inductors "oversaturated", putting an extreme load on the FETs. Again, confirming what MLS said about the "bad parts".

I'll say that's at least part of the reason that some of the amps seemed to get "hot", too. Would a bigger heat sink avoided the problem? Again, I'm not an EE, so I don't know. That said, my amp barely gets warm to the touch....even after a hard workout.

I'm going to make an assumption and a couple of questions. If the inductors seem to be the culprit, as has been reported, why not just rework the current amp with new inductors?

That's probably a lot of manual labor and may not be cost effective. That gets to the core of why this has taken so long to get a "fix" in place. First, AV123 doesn't know which amps have the bad components. And #2, even if you did know which ones were bad, does it make more sense to just redesign the amps, and find a better supplier?

Again, this is one guy taking apart one bad amp. And, it's another guy (me) wondering the which plan of action I WOULD TAKE.

Bottom line, seems like MLS decided to redesign the amps. And, doing that has taken a little while.

Originally Posted by craigsub

The original designer of the MFW-15 indicated that there was a possibility that the MFW-15's in the future would have a driver sourced outside Eminence.

Originally Posted by craigsub

I doubt the new driver (if it happens) would be "better" than what Eminence builds. Of the thousands of units which have been delivered, driver issues have been rare, and are likely the result of shipping issues.

I would also not necessarily think a driver sourced from someone outside Eminence would be "bad". It would likely be built to comparable specs.

The best advice: Wait and see what happens.

Originally Posted by craigsub

The best advice: Wait and see what happens.

Originally Posted by Wyxe

+1

Bought my MFW15 (with MTMs and CS center) on the Black Friday Sale. Sat in my garage for two months before I unpacked it. I've been using it for the past 2 months now without issue. Amp is warm all the time. Slight hum, but fixed with a cheater plug.

Originally Posted by skyriderfox

MLS has an update on the AV123 site....regarding MFW-15's in Rosewood...This was posted on 4/30/2009, so just 2 days ago.

Update MFW-15 Rosewood

Greeting all

I wanted to send along a short note to those of you waiting for MFW-15 Rosewood. I have recently posted some photos from the samples that were flown in from the completed run - and, they are really beautiful. I'm certainly pleased that these came out as nicely as they have

As many of you no doubt know, we have had some really difficult issues to overcome with the amplifier used in this product. A decision was reached a few days back that we will be using a completely newly designed amplifier module in place of the one we have. This ensures all of us that you'll have a completely perfect MFW-15 that will be all that and more well into the future. This is a copy of that note.

Dear MFW-15 amplifier folks:

I hope this note finds you well

After discussing this amplifier situation with our two Engineers here in the USA we have concluded that the singularly BEST OPTION would be to replace the amp module (board) itself inside the MFW-15.

For those of you that have been inside a '15 - you'll note that the amplifier has several modules/boards. These include the power supply module - the amp module (itself) and pre-amp/controller module. The amp module is easily replaced - and in taking this road we feel that this is THE BEST SOLUTION for the short term - and well into the life of the complete product.

Delivery time for the new amp modules is about 3 weeks - and we will immediately begin retrofitting our inventory here. The first to leave will be the Warranty Replacements - and once they are all 101% out and on their way, we will begin retrofitting all of our current Finished Goods Inventory as well as the inbound MFW-15's in Rosewood. Once these tasks are underway - we will take to retrofitting our entire remaining inventory in Colombia (we will do the replacements here in Colorado) and ready that merchandise for sale.

So - in closing let me clearly state that while fixing the amps with the correct (to spec) parts did work - we feel that in order to put our very best foot forward, we want to replace the amplifier module with new ones that perform superbly under any conditions. In doing this, we serve both you and our brand to the very best of our ability.

I will release more information next week to offer any further clarifications that may be needed.

Thank you very much


All the best

So in closing, please know that upon the arrival of the amplifiers we will install these right away into your MFW-15 Rosewood - and get it moving on its way to your home Amps are due to be shipped in 3 weeks, and then we will need some time for install and shipping Total time might be 5 weeks.

We all join in thanking you for your patience and perseverance. I'd like to convey how well worth it it will be - so I'm going to simply express it just like that - and let you be the judge once your beautiful and powerful MFW-15 arrives in your home.

With grateful thanks

All the best,

Mark L. Schifter
__________________
Mark L. Schifter
President and Founder
Perpetual Technologies / www.**********
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Originally Posted by bsoko2

I had a hum from a sub that I had and used one of these to eliminate it: http://www.parts-express.com/pe/show...number=180-075. It worked.

Bill

Originally Posted by counterpoint

I had a severe ground loop hum with my MFW-15 and tried eliminating it by removing the amp and rearranging the wires inside. It didn't work but in the process I noticed that the hum was only present when the signal cable was attached to the sub. Then I narrowed it down to my cable box and found that hum was only present when the cable box was plugged into the system. Then I narrowed it down to the RG6 cable line itself and found that the hum was only present with the cable connected.

I was in the process of switching to Dish anyway, hoping my problems would be resolved, but I was unpleasantly surprised that the ground loop hum was present when the dish network box (722) was connected to the system but it wasn't the satellite RG6 cable. Frustrated as hell, I decided to open the sucker up and see what would happen if I removed the ground wire from the chassis and eureka! It worked and the ground loop hum was 99% eliminated. There was still a tiny tiny bit of hum in the system but it was only when the gain was set at max. At half gain, which is what I normally set it at, no hum is audible at all from any distance. I know its not the safest thing to do to remove the ground from the chassis but, what the heck am I supposed to do? I don't own the box anyway. I hope this helps somebody out there with a ground loop problem. My suggestion is to remove all cables from the devices in your system one by one until you narrow down the culprit.

Here is a picture. I just covered the ground in electrical tape before closing it back up.

Originally Posted by counterpoint

I had a severe ground loop hum with my MFW-15 and tried eliminating it by removing the amp and rearranging the wires inside. It didn't work but in the process I noticed that the hum was only present when the signal cable was attached to the sub. Then I narrowed it down to my cable box and found that hum was only present when the cable box was plugged into the system. Then I narrowed it down to the RG6 cable line itself and found that the hum was only present with the cable connected.

I was in the process of switching to Dish anyway, hoping my problems would be resolved, but I was unpleasantly surprised that the ground loop hum was present when the dish network box (722) was connected to the system but it wasn't the satellite RG6 cable. Frustrated as hell, I decided to open the sucker up and see what would happen if I removed the ground wire from the chassis and eureka! It worked and the ground loop hum was 99% eliminated. There was still a tiny tiny bit of hum in the system but it was only when the gain was set at max. At half gain, which is what I normally set it at, no hum is audible at all from any distance. I know its not the safest thing to do to remove the ground from the chassis but, what the heck am I supposed to do? I don't own the box anyway. I hope this helps somebody out there with a ground loop problem. My suggestion is to remove all cables from the devices in your system one by one until you narrow down the culprit.

Here is a picture. I just covered the ground in electrical tape before closing it back up.

Originally Posted by counterpoint

I had a severe ground loop hum with my MFW-15 and tried eliminating it by removing the amp and rearranging the wires inside. It didn't work but in the process I noticed that the hum was only present when the signal cable was attached to the sub. Then I narrowed it down to my cable box and found that hum was only present when the cable box was plugged into the system. Then I narrowed it down to the RG6 cable line itself and found that the hum was only present with the cable connected.

I was in the process of switching to Dish anyway, hoping my problems would be resolved, but I was unpleasantly surprised that the ground loop hum was present when the dish network box (722) was connected to the system but it wasn't the satellite RG6 cable. Frustrated as hell, I decided to open the sucker up and see what would happen if I removed the ground wire from the chassis and eureka! It worked and the ground loop hum was 99% eliminated. There was still a tiny tiny bit of hum in the system but it was only when the gain was set at max. At half gain, which is what I normally set it at, no hum is audible at all from any distance. I know its not the safest thing to do to remove the ground from the chassis but, what the heck am I supposed to do? I don't own the box anyway. I hope this helps somebody out there with a ground loop problem. My suggestion is to remove all cables from the devices in your system one by one until you narrow down the culprit.

Here is a picture. I just covered the ground in electrical tape before closing it back up.