NEW MFW-15 amps (May 2010) *pics* - Page 51

NH

Please let me know what happened

I'm betting on the V2 burning up, the V3 makes the loudest thud when you unplug it, and I heard the thud.


I would have thought it would have blown the fuse(at IEC connector) if it shorted enough current to trip a 20A breaker?

Keep us updated! I have three of these things an want to know your findings...

Well, it was bound to happen, my 4th (I think 4th?!?) MFW-15 V2 amp took a dumper in my 2nd MFW. I'm going to use the V2 with heat issues to replace it and keep a fan running on it when ever I have it turned on.

When that one goes I'll be out of amps and looking towards the Turbo option.

KH281

Long time no see you round these forums. Good to see you again.

Not sure how long it's been since you were last here, but I remember months ago all the amp problems you have over the last year or 2.

Now that murrel has revealed the cap fix, have you attempted this on any of your amps?

I have been powering my MFW-15 with an old Sansui amp (no gain) and it's actually working quite well. I also used the turbo amp and it works great with the stock driver (as long as you don't put it too hard) so honestly, just go get yourself an external amp and hook it up. it'll be fine!!! Such as an EP2500 or so. problem solved!

Not sure what's going on..... The amps look ok. They power up and don't appear burnt up.

On a side note I noticed something with the v3, murrel, when the amp comes out of standby it's like the woofer pushes out about 1-2mm or so and when it turns off it relaxes. The v2s I have don't do this is this normal? I'm also having a pretty high noise floor with it with or without the sub cable attached.......

I would say that is not normal. unless it pushes out then returns while it is powered on. But i have no experience with your version of the V3. I have had no noise problems with the V3 amps that I have shipped.

So what blew the breaker?

Murrel

Hmmmmmm, interesting. Idk what tripped the breaker. It's a ground fault circuit also bit I've seen no cause..... It happened about 5am too shouldnt have been that much current draw in the middle of the night.

So you have no idea if either your MFW's are the cause? Have you plugged the MFW's back in to see if they are working? Is the outlet dedicated to just the two MFW's? It seems that there could be a myriad number of things that would cause it to trip if the outlet is not dedicated to the mfw's...

There were 2 mfws, an avr, tv, ps3, and dtv box all on that circuit, spread over 3 outlets. Your right there are quite a number of possibilities. My home network under the stairs is also on that circuit, modem/router/switch but they consume very little.

As I said it was the middle of the night and everything was off when it tripped. I naturally immediately thought it was the MFWs. I'm only running one now V3 and I'll monitor it for a while, then switch back to the V2 and watch it too. Its a 20 amp circuit and I routinely turn it up so I don't think its overloaded....

Hey guys, a new problem arises:

I've got a V2 that developed the loud constant buzz the week AV123 officially went under. Did the cap replacement a couple months ago and it has worked fine ever since--until today. Soon as I fired up a source this morning, it now produces what sounds like a hard drive grinding or someone dragging a piece of cloth over a live mic. The intensity varies in random intervals. I would guess the sound is generally (at the cone) around 20-30dB with the louder peaks reaching 40-50dB. Easily audible throughout the entire 20x20x9 room when quiet. Any ideas?

I guess now would be a good time to ask, any updates on the drop in amp replacement Sand? Please PM me if you can not speak candidly in the public channel, or do not wish to build false hopes. Anything said will remain private, I'm just needing some kind of time table to decide whether to just trash this thing and buy a whole new sub.

waiting to here your results. I am hoping the MFW's are fine and it is some weird anomaly that tripped your breakers...

Anyone know how many amps the V2s and V3s pull each?

I have 2 MFW-15s, one with a V1 amp and one with a V2 amp. Based on some advice from another forum, I bought a device that allows me to power them both down when not in use. I haven't had any problems since I went to this setup over a year ago, but if I go some time before powering them up, the one with the V2 amp hums for about a minute and then the hum goes away.

I've read some on this thread recommend keeping them powered on all the time, not even in stand-by. I'm wondering if I've been doing the right thing, or if the temporary hum on the one might be indicating I should keep them powered on.

Correct me if I am wrong murrel...

The majority of the hum issues are due to blown caps.
The blown caps usually occur when the amp switches on/off.

I beleive that is why some recommend to keep it on all the time-less opportunity for the caps to blow.

Right, but my only hum issue is with one sub when I haven't powered them on in a day or two, and it goes away after a minute. I went through a period when I had to replace several amps (when they were still sending them out.) Since I went to this setup, I haven't had any problems with the amps, other than that occasional, temporary humming from one. I would hate to start keeping them on in order to prevent the temporary humming and end up hastening the actual demise of one or both amps. I admit I don't know much about how these electronics work.

If you havent already, it wouldnt hurt to replace the caps on your amp-it may fix the temporary hum issue you are having. I had two humming amps and 1 non-humming amp and had the caps replaced on all 3. No more hum. I personally leave them on Auto. I figure if the fix is only temporary and if the caps blow again in a year or two, I will spend the $15 and get them replaced again. Sure beats buying new subs. MFWs are great subs-when not humming to their own tune.

You are right FoSheezy,

Leave them on.

paligap as far as the hum when you turn it on. it is a failing cap on the power supply board.....eventually the hum will not disappear. Do the fix and that should solve the hum.

If you have any questions please feel free to contact me
simplysound@msn.com

Murrel

Thanks for the advice and info, guys. I just might go ahead and do the fix, but since I have only one amp that hums only temporarily on occasion, I wonder if I should just leave that one on (not auto.) And since the fix document indicates that the fix applies only to V2 amps, I could continue to power off the one with the V1 amp when not in use--unless there is some reason not to.

Guys...listen seriously. After doing the cap replacement and then having a freaking FIRE (luckily I was home and right there to pull the plug) I would not even CONSIDER using ANY mfw amplifier of any kind, under any circumstances!!! Just buy an external amp like a Behringer A500, ep2500, Crown xls1000 etc for $200.00 and be SAFE!!!

I could have easily burned my house down..lost everything and killed my dog. it's just not worth it in my opinion!!!

This is most unfortunate. I am glad no one was hurt and no property was damaged (except the damn amp ). Your experience seems to be an isolated event. I certainly hope no one else had or has this experience. What do you think the root cause of the failure was? There are a lot of these amps out here, this could be very useful info.

well, it has been suggested that possibly the new caps were put in backwards, but since an engineer did it for me i really doubt that. i think the design of these amps and boards are just plain crap. they are not designed well, are obviously not safe, and use the cheapest parts you can find. One of the caps on one board exploded (not a replaced one btw) and I had flames and lighitning shooting out the back of my amp. All I know is....there is NO way I would ever consider plugging in an MFW-15 amplifier of any kind in my house again...nor anyone else I know.

My MFW-15 makes me nervous, with it's heat and the aforementioned raspy paper across the microphone noise I get when I unplug and/or turn it off. I bought an original first run V1 from a Turbo buyer for security, and to increase resale value, but haven't had to use it yet. I also have a new OEM 15" driver on reserve.

I am upgrading to dual sealed 18's. Hoping to either sell the whole MFW-15 kit and kaboodle or Turbo it just for fun in the future.

"flames AND lightning" sounds like quite a show! Where did the flames and lightning exit out of the back of the amp? I would have saved the board and taken pictures! So, has anyone else, besides PE, experienced catastrophic failure of one of these amps?
I also thought one of the main reason one wanted to use the amp that was designed for the mfw is because it has the appropriate eq and is tailored to work with the driver?

If you push in on the driver by itself does it make the "raspy" sound? It may be a blown driver...just a thought. Having read this entire thread in two days I think I recall someone else with that issue. Or it could have been on the other forum I was on reading about these things...

Lol I did. Search for my post

searched through all FOUR pages of your posts in this thread and then realized you must have started a different one. That looked scary!

Yup. It was!!!!

I'm wondering about the eq of the amp as well. I have an ep1500 I could use, but there wouldn't be any equalization, correct?