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

post #121 of 230
Quote:
Originally Posted by deez View Post

Please let us know.

Ok, just checked out both subs and aside from the line in wire being loose, the teeth marks give the cat away, damn little furball. I replaced that cable and ran a balls to the wall test which I had yet to do with these two set up properly.

Using the Blue Man Group Audio DVD and the song "Club Nowhere" the radio shack meter read from the primary sweet spot 120db and several 118 and 119db spikes. Anybody who knows this song knows it hits hard and often. I was using C weighting and slow response. I managed to take a picture of the meter while I was measuring, I had to snap the pic with my iphone which is no easy task. I'll post it when I hook the phone up to the PC it hooks up to.

I'm open to someone from my area coming over to tell me if I'm insane or these really hit that hard as a combo or my meter is wacked.

Needless to say both subs are doing their job!
post #122 of 230
Quote:
Originally Posted by Lhasa-lover View Post

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.

Oh, so my amp is bad and I don't realizeit, but I should, 'cause my grill has never been "blown" off by massive amounts of air being pushed? I doubt it.

Seriously, there's something wrong with your magnets. Misaligned or weak, probably. Same with anyone else's who's had their grills fall off... it's not massive subwoofer performance that's doing it. Yeah, mine pushes lots of air, pressurizes the room, makes my pants legs flap, hits HARD!... Choose your inane subwoofer cliche... Grill never falls off.
post #123 of 230
Quote:
Originally Posted by stereojunkie View Post

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.

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.
post #124 of 230
Quote:
Originally Posted by Lhasa-lover View Post

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.

It's custom made by Eminence.

http://www.eminence.com
post #125 of 230
This thread needs to be locked.

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

Moderator, lock this thread please, thanks.
post #126 of 230
Quote:
Originally Posted by James W. Johnson View Post

This thread needs to be locked.

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

Moderator, lock this thread please, thanks.

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.
post #127 of 230
Quote:
Originally Posted by James W. Johnson View Post

This thread needs to be locked.

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

Moderator, lock this thread please, thanks.

Things have not degenerated nearly enough to warrant a lock... Read a few other threads on this forum. Nearly all of them stray a little OT at times. Besides, the basis of our "rediculous"-ness was related to amp performance, in a roundabout sort of way, so... relax.

Anyhow, we haven't heard from the OP in a while... How goes it with the new amp, deez?
post #128 of 230
Quote:
Originally Posted by graphicguy View Post

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.

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.
post #129 of 230
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.
post #130 of 230
Quote:
Originally Posted by mdaudioguy View Post

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.

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.
post #131 of 230
Quote:
Originally Posted by graphicguy View Post

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.

Well said post. Did Lance take pictures of the amp taken apart?
post #132 of 230
Quote:
Originally Posted by craigsub View Post

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.

Did he possibly mention which driver might be replacing the current one? As I have already had to replace one, might I be better off with the newer one, if it happens. Hmmm.
post #133 of 230
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.
post #134 of 230
Quote:
Originally Posted by craigsub View Post

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.

Makes sense. The one I had to replace, I believe, was just a fluke problem. I never thought that there was any driver problems similar to what is happening with the amps.
post #135 of 230
Quote:
Originally Posted by craigsub View Post

The best advice: Wait and see what happens.

Why would we want to wait?? Bring on the wild speculation!

Just kidding...
post #136 of 230
Thread Starter 
Quote:
Originally Posted by graphicguy View Post

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.

Your talking about the "Defectively built" amp right?

Because, from what I have been told, The amps went bad from his supplier using black market parts, pocketing the money and then leaving town. The new amp is not a redesign-it just has a new output board and upgraded caps.

FWIW, my amp sounds great!

I don't know if thier is any difference technically but to my ear it does sound different than before.......it sounds more consistent. I dont know if that makes any sense but thats what I hear.
post #137 of 230
My second amp is still going strong.....being punished weekly if not daily..
post #138 of 230
Deez....I gotta admit, I'm ignorant when it comes to electrical engineering for a subwoofer amp.

But, the important thing is, YOU like what you're hearing. That's all the really matters.

Just saw another post by Doug Goldberg over at TWEAK CITY AUDIO. He confirmed that the inductor was indeed the culprit.

He mentioned that the new one is a crystal controlled amp. I don't know what that means. Sounds good, though.
post #139 of 230
This is just a space-saver post to let you know I'll be posting at some point today. More on this later.
post #140 of 230
What???????????????????
post #141 of 230
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.**********
Reply With Quote
post #142 of 230
Quote:
Originally Posted by Wyxe View Post

+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.

Well, I think I must have Jinxed myself. My amp went out today. I so wanted to believe. I guess at least I won't (hopefully) have to wait as long as some of you have for a replacement.
post #143 of 230
Thanks for posting this skyriderfox.

Quote:
Originally Posted by skyriderfox View Post

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.**********
Reply With Quote
post #144 of 230
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.

post #145 of 230
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
post #146 of 230
Quote:
Originally Posted by bsoko2 View Post

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

"Note: Interferes with digital cable, cable modem, and satellite TV operation."
Kinda removes it from being viable for most people no?
post #147 of 230
Quote:
Originally Posted by counterpoint View Post

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.


Why not just use a cheater which also removes the ground without having to remove the amp?
post #148 of 230
Mine hummed and a cheater plug did not help.

This is what fixed mine, the only way I could find this thread was a Google Cache, HERE IT IS.
post #149 of 230
Quote:
Originally Posted by counterpoint View Post

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.


I fixed my ground loop problem by removing the coaxial audio cable going from my cable box to my receiver and replacing it with an optical audio cable. This is much safer than removing the ground wire, and it works great (assuming you have optical inputs on your receiver).

--Mark
post #150 of 230
Quote:
Originally Posted by counterpoint View Post

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.




And remember kids! To alway replace the ground wire before turning the box in to your friendly neighborhood HD provider........
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