AV123 MFW-15 static issue (not hum) - AVS Forum
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Old 08-13-2014, 07:42 PM - Thread Starter
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AV123 MFW-15 static issue (not hum)

I've had the MFW-15 for a few years now and had to replace the amp twice right after I got it. It has the V2 amp which developed the famous "hum" issue so I did the cap replacement per Murrel's instructions a couple years ago and it's been great ever since (thanks Murrel!). Only recently has it developed an issue with low-level static (not the hum) that goes up and down in volume. Sometimes I don't hear it at all but it's happening pretty regularly now.

I've tried googling for a static issue with the MFW-15 but the results are always related to the hum issue. Anybody else ever have a static issue and/or have any thoughts about possible fixes (if it can be fixed)? I've changed no components in my HT setup for years. The MFW-15 is the bane of my existence!

Any help or suggestions are appreciated. Thanks.

Adam
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Old 08-18-2014, 10:15 AM
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Originally Posted by adamcornwell View Post
I've had the MFW-15 for a few years now and had to replace the amp twice right after I got it. It has the V2 amp which developed the famous "hum" issue so I did the cap replacement per Murrel's instructions a couple years ago and it's been great ever since (thanks Murrel!). Only recently has it developed an issue with low-level static (not the hum) that goes up and down in volume. Sometimes I don't hear it at all but it's happening pretty regularly now.

I've tried googling for a static issue with the MFW-15 but the results are always related to the hum issue. Anybody else ever have a static issue and/or have any thoughts about possible fixes (if it can be fixed)? I've changed no components in my HT setup for years. The MFW-15 is the bane of my existence!

Any help or suggestions are appreciated. Thanks.

Adam
Good morning Adam..........well at least it is nice outside here in Colorado!

I do not have good news for you. This is a common problem with the MFW amps. I will get right to the point, without a good schematic and a bill of materials this problem is almost impossible to debug and repair. It is an output board problem and is usually related to some of the components in the pre amp area of the board. problem is they are all surface mount parts, very small and not clearly marked. It is a problem that not even I felt like tacking as it would take lots of time and really no return on that time.

Adam I do not want to ruin your day but the MFW is now going on 7 or so years old, no company around to support it, no spare parts. If you have a special cabinet I would look into Kevin's turbo or a external amp to run your sub. Other wise spend your money on a new sub with a company that will stand behind it (warranty) and then you can enjoy your system with out worring about the ever present possibility of MFW failure!

I know its probably not what you wanted to hear but I hear about this issue now more than I do the hum.

Let me know if I can help
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Old 08-19-2014, 10:27 AM - Thread Starter
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Originally Posted by murrel View Post
Good morning Adam..........well at least it is nice outside here in Colorado!

I do not have good news for you. This is a common problem with the MFW amps. I will get right to the point, without a good schematic and a bill of materials this problem is almost impossible to debug and repair. It is an output board problem and is usually related to some of the components in the pre amp area of the board. problem is they are all surface mount parts, very small and not clearly marked. It is a problem that not even I felt like tacking as it would take lots of time and really no return on that time.

Adam I do not want to ruin your day but the MFW is now going on 7 or so years old, no company around to support it, no spare parts. If you have a special cabinet I would look into Kevin's turbo or a external amp to run your sub. Other wise spend your money on a new sub with a company that will stand behind it (warranty) and then you can enjoy your system with out worring about the ever present possibility of MFW failure!

I know its probably not what you wanted to hear but I hear about this issue now more than I do the hum.

Let me know if I can help
Thanks Murrell, I was afraid of that. What do you mean by "special cabinet?" I have rosewood.

I have a secondary MFW cone laying around as well. I'm pretty handy and wonder if there are any good single or dual 15" DIY instructions floating around? I do like the rosewood cabinet it's in though. Any amp recommendations for going external?

Adam

In response to your ad on craigslist-
http://seattle.craigslist.org/est/sys/4490754375.html


Sent via Mokriya Craigslist


Sent from my iPhonehave the rosewood cabinet. I have a secondary MFW-15 cone laying around.
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Old 08-19-2014, 12:16 PM
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Adam,

I would consider the rosewood cabinet special........Look find yourself a good sub amp it could be a bash or a dayton yes lots to choose from. You can hook your driver directly to the biding posts on the MFW amp. I have had plenty of people just purchse a plate amp and build a nice enclosure for it. But that is all up to how much you want to spend and how much work you want to put into the sub. Parts express has plenty to choose from. 500 watts would be more than enough.



Good luck!

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Old 08-19-2014, 12:22 PM - Thread Starter
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Adam,

I would consider the rosewood cabinet special........Look find yourself a good sub amp it could be a bash or a dayton yes lots to choose from. You can hook your driver directly to the biding posts on the MFW amp. I have had plenty of people just purchse a plate amp and build a nice enclosure for it. But that is all up to how much you want to spend and how much work you want to put into the sub. Parts express has plenty to choose from. 500 watts would be more than enough.



Good luck!
Great, thanks. I'll check out some options.
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Old 08-20-2014, 09:13 PM
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There is a DIY dual for using the MFW-15 drivers that I modified an amp for that works pretty good. Cabinet is pretty good sized though at 2.5ft per driver. Turbo kits are actually in stock and ready to ship for once. let me know if you have any questions

Kevin
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