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NEW MFW-15 amps (May 2010) *pics* - Page 61

post #1801 of 2481
6/27/11 at 1:38pm
Quote:
Originally Posted by joshmvf View Post
Thanks, I took a look at it, but since I've never soldered anything in my life, I'm a little hesitant.

Do you know if anybody does this fix and charges for it? I'd be happy to pay someone to have it done and pay for the postage there and back. If not I'll probably go buy a soldering iron and give it a shot I suppose.

Thanks again,
If you have never soldered or are not very good at it....do not attempt it. You will damage the board and I have no spares. Many have just purchased the parts, removed the amp, removed the board and found a local shop to do the parts replacement.


Let me know if you need help
Murrel
simplysound@msn.com
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post #1802 of 2481
6/28/11 at 7:15pm
I had a technician do the hum fix to one of my 2 MFWs for a very reasonable price. It mostly fixed the hum, although, if I get very close, I can hear a small hum. My other one used to hum for a minute or so after I powered it up and then stop. On the advice of many on this thread and others, I stopped powering it down. Now it emits a low hum all the time, slightly louder than the other MFW.

Having had several of these amps go bad on me--once when I wasn't home--I'm feeling less and less comforable leaving both subs powered on all the time. I guess these are my options:
  1. Do the hum fix on the one I haven't and keep both subs powered on all the time.
  2. Replace my V2 amps with V3s.
  3. Get rid of one MFW and do the Turbo upgrade.
  4. Get rid of both and get one or two new ones.
I wouldn't want to get V3 amps if they have to be left on all the time. I'm not sure what I'd be losing, if anything, by going from dual MFWs to a single Turbo or other sub. I have a 16 X 16 hexagonal room with a cathedral ceiling about 20 feet high in the middle. The room has several openings to a surrounding hallway and other rooms. My receiver has Multeq XT, but not XT 32.

I've been mostly happy with the sound of the MFWs, but I used a graphing program last weekend and discovered that I have some issues with my room, which has some treatments. I moved both subs and got a slightly better graph. I applied some filters with an Onix R-DES unit (I know, I know--it was borrowed). It helped even more, but wouldn't you know it, the unit started making an annoying, almost constant, mini-thumping come from the subs, so I had to bypass it. What I'm getting at is that I don't really know if I need two subs or just one good one for my room.
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post #1803 of 2481
6/28/11 at 8:33pm
Quote:
Originally Posted by paligap View Post

I had a technician do the hum fix to one of my 2 MFWs for a very reasonable price. It mostly fixed the hum, although, if I get very close, I can hear a small hum. My other one used to hum for a minute or so after I powered it up and then stop. On the advice of many on this thread and others, I stopped powering it down. Now it emits a low hum all the time, slightly louder than the other MFW.

Having had several of these amps go bad on me--once when I wasn't home--I'm feeling less and less comforable leaving both subs powered on all the time. I guess these are my options:

[*]Do the hum fix on the one I haven't and keep both subs powered on all the time.[*]Replace my V2 amps with V3s.[*]Get rid of one MFW and do the Turbo upgrade.[*]Get rid of both and get one or two new ones.

I wouldn't want to get V3 amps if they have to be left on all the time. I'm not sure what I'd be losing, if anything, by going from dual MFWs to a single Turbo or other sub. I have a 16 X 16 hexagonal room with a cathedral ceiling about 20 feet high in the middle. The room has several openings to a surrounding hallway and other rooms. My receiver has Multeq XT, but not XT 32.

I've been mostly happy with the sound of the MFWs, but I used a graphing program last weekend and discovered that I have some issues with my room, which has some treatments. I moved both subs and got a slightly better graph. I applied some filters with an Onix R-DES unit (I know, I know--it was borrowed). It helped even more, but wouldn't you know it, the unit started making an annoying, almost constant, mini-thumping come from the subs, so I had to bypass it. What I'm getting at is that I don't really know if I need two subs or just one good one for my room.

Sell and run for another sub would be my suggestion. A single 18" will best your dual mfw's
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post #1804 of 2481
6/29/11 at 7:45am
Quote:
Originally Posted by Pure-Evil View Post

Sell and run for another sub would be my suggestion. A single 18" will best your dual mfw's

and the greatest thread crapper of the mfw15 returns with yet another fabulous answer based on nothing but his disdain for the mfw15! Folks, they don't call him Pure-Evil for nothing!
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post #1805 of 2481
6/29/11 at 8:24am
Quote:
Originally Posted by Pure-Evil View Post

Sell and run for another sub would be my suggestion. A single 18" will best your dual mfw's

It is hard to believe that you are able to pressurize your huge living space with just one sub. You used to have four vented MFW-15's in that space, you are telling us that one 18" sealed sub has more output?

How big is that room again, and the rooms that are open to it? It is like the size of a small gymnasium IIRC.
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post #1806 of 2481
6/29/11 at 8:34am
Quote:
Originally Posted by paligap View Post

I had a technician do the hum fix to one of my 2 MFWs for a very reasonable price. It mostly fixed the hum, although, if I get very close, I can hear a small hum. My other one used to hum for a minute or so after I powered it up and then stop. On the advice of many on this thread and others, I stopped powering it down. Now it emits a low hum all the time, slightly louder than the other MFW.

Having had several of these amps go bad on me--once when I wasn't home--I'm feeling less and less comforable leaving both subs powered on all the time. I guess these are my options:
  1. Do the hum fix on the one I haven't and keep both subs powered on all the time.
  2. Replace my V2 amps with V3s.
  3. Get rid of one MFW and do the Turbo upgrade.
  4. Get rid of both and get one or two new ones.
I wouldn't want to get V3 amps if they have to be left on all the time. I'm not sure what I'd be losing, if anything, by going from dual MFWs to a single Turbo or other sub. I have a 16 X 16 hexagonal room with a cathedral ceiling about 20 feet high in the middle. The room has several openings to a surrounding hallway and other rooms. My receiver has Multeq XT, but not XT 32.

I've been mostly happy with the sound of the MFWs, but I used a graphing program last weekend and discovered that I have some issues with my room, which has some treatments. I moved both subs and got a slightly better graph. I applied some filters with an Onix R-DES unit (I know, I know--it was borrowed). It helped even more, but wouldn't you know it, the unit started making an annoying, almost constant, mini-thumping come from the subs, so I had to bypass it. What I'm getting at is that I don't really know if I need two subs or just one good one for my room.

Leaving the MFW amps on continuously may expose you to potential risks due to fire. I seem to recall there was at least one person, Pure-Evil I think, who showed some pictures of some internal charring or worse. You do understand that the markings that are on the back of the amps are for show. They never were subjected to UL testing for safety.
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post #1807 of 2481
6/29/11 at 6:27pm
Quote:
Originally Posted by paligap View Post

I had a technician do the hum fix to one of my 2 MFWs for a very reasonable price. It mostly fixed the hum, although, if I get very close, I can hear a small hum. My other one used to hum for a minute or so after I powered it up and then stop. On the advice of many on this thread and others, I stopped powering it down. Now it emits a low hum all the time, slightly louder than the other MFW.

Having had several of these amps go bad on me--once when I wasn't home--I'm feeling less and less comforable leaving both subs powered on all the time. I guess these are my options:
  1. Do the hum fix on the one I haven't and keep both subs powered on all the time.
  2. Replace my V2 amps with V3s.
  3. Get rid of one MFW and do the Turbo upgrade.
  4. Get rid of both and get one or two new ones.
I wouldn't want to get V3 amps if they have to be left on all the time. I'm not sure what I'd be losing, if anything, by going from dual MFWs to a single Turbo or other sub. I have a 16 X 16 hexagonal room with a cathedral ceiling about 20 feet high in the middle. The room has several openings to a surrounding hallway and other rooms. My receiver has Multeq XT, but not XT 32.

I've been mostly happy with the sound of the MFWs, but I used a graphing program last weekend and discovered that I have some issues with my room, which has some treatments. I moved both subs and got a slightly better graph. I applied some filters with an Onix R-DES unit (I know, I know--it was borrowed). It helped even more, but wouldn't you know it, the unit started making an annoying, almost constant, mini-thumping come from the subs, so I had to bypass it. What I'm getting at is that I don't really know if I need two subs or just one good one for my room.

Getting a v3 amp is a viable option. To date they have shown to be very reliable and non problematic. They run cool, and there's no hum whatsoever with them. Murrel can sell you some. It's the amp that really should have come with the MFW. You don't need to leave it on 24/7. You can safely shut it off and on with np's. Same goes for leaving it in the auto on setting.
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post #1808 of 2481
6/29/11 at 6:28pm
Quote:
Originally Posted by Chu Gai View Post

Leaving the MFW amps on continuously may expose you to potential risks due to fire. I seem to recall there was at least one person, Pure-Evil I think, who showed some pictures of some internal charring or worse. You do understand that the markings that are on the back of the amps are for show. They never were subjected to UL testing for safety.

I think that amp you're referring to Chu, had to do with a cap fix done on a v1 amp. Which I recall if memory serves me correct, murrel saying that doing so on a v1 amp won't work. Couple that with PE possibly pushing the amp maybe harder than it should be pushed..........? Equals recipe for a nice little fire.
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post #1809 of 2481
6/30/11 at 7:39am
Quote:
Originally Posted by Chu Gai View Post

Leaving the MFW amps on continuously may expose you to potential risks due to fire. I seem to recall there was at least one person, Pure-Evil I think, who showed some pictures of some internal charring or worse. You do understand that the markings that are on the back of the amps are for show. They never were subjected to UL testing for safety.

Wasn't PE at home with his hands on the wheel when this happened? Not the first time he overloaded an amp, either.

Quote:
Originally Posted by yadfgp View Post

Couple that with PE possibly pushing the amp maybe harder than it should be pushed..........? Equals recipe for a nice little fire.

I'm thinking the same. It's really hard to fill that gymnasium of his with just one sub. Cranking up the volume to try and match the beats in the car ain't gonna cut it!
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post #1810 of 2481
6/30/11 at 8:21am
Quote:
Originally Posted by tesseract67 View Post

Wasn't PE at home with his hands on the wheel when this happened? Not the first time he overloaded an amp, either.

Could be. Doesn't change the fact that an amp ought not behave that way nor the fact the UL listing on the amp was a sham.
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post #1811 of 2481
6/30/11 at 9:34am
Quote:
Originally Posted by Chu Gai View Post

Could be. Doesn't change the fact that an amp ought not behave that way nor the fact the UL listing on the amp was a sham.

They were built very inconsistently, with huge failure rates, but they never had a UL logo, just CE (which is mostly a self-certification process). My own amplifiers at 3-20x the cost and assembled in the US do carry a UL rating, but it is not required for domestic use. It is a voluntary certification which may be required in some uses per local codes and applications. The various UL ratings can also make it much easier to also comply with other international regulations. The certification really indicates that you've passed testing indicating you've covered all practical safety efforts and gone through third party testing to affirm that.

The case of Pure-Evil's amp also was right after a modification was made... after the amp had already failed. Any time electronics are worked on, they should be powered back up and watched for a short time to insure no errors were made. This was an attempt to fix an amp that had already failed, and while amusing and alarming, isn't directly relevant to most owners. As I recall this occurred rather soon after powering back up the amplifier.
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post #1812 of 2481
6/30/11 at 4:32pm
Quote:
Originally Posted by Chu Gai View Post

Could be. Doesn't change the fact that an amp ought not behave that way nor the fact the UL listing on the amp was a sham.

It does change the fact as I had previously stated. If he did modify as I suggested then that changes the way it will behave which apparently it did. Nice little fire.
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post #1813 of 2481
6/30/11 at 5:54pm
Quote:
Originally Posted by yadfgp View Post

I think that amp you're referring to Chu, had to do with a cap fix done on a v1 amp. Which I recall if memory serves me correct, murrel saying that doing so on a v1 amp won't work. Couple that with PE possibly pushing the amp maybe harder than it should be pushed..........? Equals recipe for a nice little fire.

Thats correct, i´m in Colombia and i have a V1 amp and for me the only way is to fix the sub, so a technician here fix it, the first time he doesn´t change all the components that were bad, so after 30 minutes watching a movie the hum start again.

Now the sub is really fixed and it cost no more than US$50, you just have to change a couple of pieces and it´s done, if remember well the parts are:

4x FB31N20D (i have to import them from china, impossible to buy it here)
1x LM311P integrated
1x A42 transistor
1x TL072CN integrated
And the capacitors Murrel said to fix the V2 amp, 2x470uF 50v, 1x 22uF 160v, 1x 1000uF 35v

The parts should´t cost more than US$15.
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post #1814 of 2481
7/7/11 at 4:09pm
not sure if this is the correct place for this post but.

Well i just recently found out av123 is out of business. I own 2 mfw-15 that i bought in July and August of 2008. They have not had any problems and i recommended my parents get one and they ordered one in December of 2008.

They had the amp replaced once by av123 around a year ago and it has went out again.

I have read and see that most of their amps are about useless unless they were manufactured before Nov. of 2008.

They are in need of an amplifier so if anyone has one for sale please let me know. I know of the new one that is for 225 but that is out of their budget at this current time.

Also do i need to be worried about the two i have with the v1 amps? Are they going to go out soon or are those the best batch that av123 had.

I also see the v2 amp has a fix but you need to be good with a solder gun. Any way to tell what version the amp is and how difficult would it be for someone who has never soldered anything?

I just feel bad that i recommended this speaker to my parents and then the way this company did everybody. When i had purchased these subs they were highly rated and reviewed.

Thanks for any information.
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post #1815 of 2481
7/7/11 at 4:38pm
Shawn784,

You are more than welcome to email me. I may be of some help to you

Murrel
simplysound@msn.com
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post #1816 of 2481
7/8/11 at 8:06am
Quote:
Originally Posted by shawn784 View Post

not sure if this is the correct place for this post but.

Well i just recently found out av123 is out of business. I own 2 mfw-15 that i bought in July and August of 2008. They have not had any problems and i recommended my parents get one and they ordered one in December of 2008.

They had the amp replaced once by av123 around a year ago and it has went out again.

I have read and see that most of their amps are about useless unless they were manufactured before Nov. of 2008.

They are in need of an amplifier so if anyone has one for sale please let me know. I know of the new one that is for 225 but that is out of their budget at this current time.

Also do i need to be worried about the two i have with the v1 amps? Are they going to go out soon or are those the best batch that av123 had.

I also see the v2 amp has a fix but you need to be good with a solder gun. Any way to tell what version the amp is and how difficult would it be for someone who has never soldered anything?

I just feel bad that i recommended this speaker to my parents and then the way this company did everybody. When i had purchased these subs they were highly rated and reviewed.

Thanks for any information.

In my last post i put some info in how to fix that amps, by the way i didn't do it, i pay someone to do it, just $20 for the fix plus the parts.
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post #1817 of 2481
7/8/11 at 1:02pm
Well, I ordered a V3 amp from Murrel. It shipped quickly, and I installed it today. It doesn't exactly run cool, but compared to the V2 amp, it's absolutely freezing. If it continues to be problem-free, I'll probably order another one to replace the V2 amp I did the cap fix on.

Thanks, Murrel, for the cap fix and the new amp.
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post #1818 of 2481
7/8/11 at 1:04pm
Quote:
Originally Posted by paligap View Post
Well, I ordered a V3 amp from Murrel. It shipped quickly, and I installed it today. It doesn't exactly run cool, but compared to the V2 amp, it's absolutely freezing. If it continues to be problem-free, I'll probably order another one to replace the V2 amp I did the cap fix on.

Thanks, Murrel, for the cap fix and the new amp.
You are welcome!

Murrel
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post #1819 of 2481
7/8/11 at 5:16pm
Quote:
Originally Posted by paligap View Post

Well, I ordered a V3 amp from Murrel. It shipped quickly, and I installed it today. It doesn't exactly run cool, but compared to the V2 amp, it's absolutely freezing. If it continues to be problem-free, I'll probably order another one to replace the V2 amp I did the cap fix on.

Thanks, Murrel, for the cap fix and the new amp.

Soundwise did the V3 appear to be an upgrade or did it essentially sound the same as the V2.

And props again to Murrel, a very stand up guy that also helped me a while back!
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post #1820 of 2481
7/8/11 at 5:27pm
Quote:
Originally Posted by heterology View Post

Soundwise did the V3 appear to be an upgrade or did it essentially sound the same as the V2.

And props again to Murrel, a very stand up guy that also helped me a while back!

My pleasure gentlemen!

Murrel
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post #1821 of 2481
7/8/11 at 7:53pm
Quote:
Originally Posted by heterology View Post

Soundwise did the V3 appear to be an upgrade or did it essentially sound the same as the V2.

And props again to Murrel, a very stand up guy that also helped me a while back!

In my experience with 2 v2's and 2 v3's they sound the same. I'm sure most will agree with this as well.
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post #1822 of 2481
7/9/11 at 7:25am
Quote:
Originally Posted by heterology View Post

Soundwise did the V3 appear to be an upgrade or did it essentially sound the same as the V2.

And props again to Murrel, a very stand up guy that also helped me a while back!

To me, it sounds the same. One thing I did notice is that when it's in standby mode and there hasn't been a signal for some time, the light stays green, instead of switching to red like the V2 does. However, when I used my remote to power the subs off, the V3 didn't "burp" unpleasantly like my V2 would if I powered it off while the light was still green. So I assume that either the v3 was really in standby mode or it just doesn't have the same problem powering off that the V2 does.
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post #1823 of 2481
7/9/11 at 11:51am
Quote:
Originally Posted by paligap View Post
To me, it sounds the same. One thing I did notice is that when it's in standby mode and there hasn't been a signal for some time, the light stays green, instead of switching to red like the V2 does. However, when I used my remote to power the subs off, the V3 didn't "burp" unpleasantly like my V2 would if I powered it off while the light was still green. So I assume that either the v3 was really in standby mode or it just doesn't have the same problem powering off that the V2 does.
If the three way silver switch in the back is in the middle position, the V3 should go into standby also, but it does take a considerable amount of time before it does. It also is more sensitive to incoming signal, coming on much faster than the V2.

I sometimes had turned off my system locked up house and got into bed when I finally heard the sub clunk off. This was however before, when I had a considerable ground loop hum so the clunk was noticeable.

They do sound similar, and track closely doing REW sweeps the V2 does extend a bit lower below tuning, possibly due to lack of proper driver control, but the V3 does have more available headroom, IMO.

I have the V3.0 which has the toroidal and that toroidal runs cold as a cucumber but does exhibit a bit of what I call DC humm which i think is normal for a toroid? Anyways there is a quiet humm or buzz if you put your ear right down to the amp plate.

I have three, and wish they all had V3.1s.

OH, Murrel hows the stock on the amps? I see the MFW drivers from the surplus are all gone. How is the stock on the amps?
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post #1824 of 2481
7/9/11 at 3:28pm
Quote:
Originally Posted by NicksHitachi View Post


If the three way silver switch in the back is in the middle position, the V3 should go into standby also, but it does take a considerable amount of time before it does. It also is more sensitive to incoming signal, coming on much faster than the V2.

I sometimes had turned off my system locked up house and got into bed when I finally heard the sub clunk off. This was however before, when I had a considerable ground loop hum so the clunk was noticeable.

They do sound similar, and track closely doing REW sweeps the V2 does extend a bit lower below tuning, possibly due to lack of proper driver control, but the V3 does have more available headroom, IMO.

I have the V3.0 which has the toroidal and that toroidal runs cold as a cucumber but does exhibit a bit of what I call DC humm which i think is normal for a toroid? Anyways there is a quiet humm or buzz if you put your ear right down to the amp plate.

I have three, and wish they all had V3.1s.

OH, Murrel hows the stock on the amps? I see the MFW drivers from the surplus are all gone. How is the stock on the amps?

The stock is fine. Sometimes it is a little slow getting the amps done. I am a pretty small portion of QSC's business. Things have really picked up around here for them as a company. But I always get the amps I ask for.

Have a good weekend NH
Murrel
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post #1825 of 2481
7/9/11 at 3:44pm
Good to know! I didn't know they were making them!!! I thought you had a stock of them......

Really Murrel, call me Nick! Here I'm Nickshitachi everywhere else it's Nottaway, but your the man and YOU can call me Nick!
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post #1826 of 2481
7/9/11 at 3:47pm
Quote:
Originally Posted by NicksHitachi View Post

Good to know! I didn't know they were making them!!! I thought you had a stock of them......

Really Murrel, call me Nick! Here I'm Nickshitachi everywhere else it's Nottaway, but your the man and YOU can call me Nick!

Alright Nick!!!

I do try to keep some in stock but there has been quite the rush on them lately!

Thanks Nick
Murrel
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post #1827 of 2481
7/11/11 at 12:03pm
considering picking up a used mfw... hmmm
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post #1828 of 2481
7/12/11 at 8:31am
Quote:
Originally Posted by goonstopher View Post

considering picking up a used mfw... hmmm

It's all about price point now. The performance s quite good if you get one sub $400..just don't count on the amp working forever...
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post #1829 of 2481
7/12/11 at 9:28am
Quote:
Originally Posted by streamerlover View Post

It's all about price point now. The performance s quite good if you get one sub $400..just don't count on the amp working forever...

I should read more but have people been having success with the amp fix?
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post #1830 of 2481
7/12/11 at 11:09am
Quote:
Originally Posted by goonstopher View Post

I should read more but have people been having success with the amp fix?

Yes many have had great results

You can find the link to it in my sig


Murrel
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