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NEW MFW-15 amps (May 2010) *pics* - Page 86

post #2551 of 2590

Thanks everyone. I'll let you know how it goes...

post #2552 of 2590
Here is a pic of the coil that i burnt up. Anyone know what value it is? The amp was humming along like usual and it started to make crackling sounds so after a day of that I took it out and the amp was hot and this coil was burnt up. I had a replacement that I swapped out that had the cap fix so it is good. I did the cap fix on this amp now for a backup but I want to replace the coil



post #2553 of 2590

Hi,

 

I was wondering if the capacitor burnouts are in any way due to power fluctuations? I hadn't been running my MFW's via my server class 'sine wave' UPS and APC H-15 power conditioner before my capacitor blowout. Does anyone believe that doing so will help prevent another capacitor issue in the future?

 

My replacement caps arrive today so I hope that by next week I'll know if the replacements revive my buzzing MFW.

 

Ken

post #2554 of 2590
Quote:
Originally Posted by KenV99 View Post

Hi,

I was wondering if the capacitor burnouts are in any way due to power fluctuations? I hadn't been running my MFW's via my server class 'sine wave' UPS and APC H-15 power conditioner before my capacitor blowout. Does anyone believe that doing so will help prevent another capacitor issue in the future?

My replacement caps arrive today so I hope that by next week I'll know if the replacements revive my buzzing MFW.

Ken

Just one opinion here but I think it boils down to a really poor design. Failure of the V1 and V2 amps is inevitable. I think the only precaution one could take is not plugging them in.

My V2 amp that had been problem free for years gave up the ghost a month ago. Input board went bad. Checked the caps and they were all bulging as well and would require replacement. I sold the driver already but my son wants to keep the cabinet as he is thinking about doing the turbo upgrade. Meanwhile I have been enjoying my dual CHT VS18.1's for more than a year now anyway. The mfw is a toy compared to those beasts.
post #2555 of 2590

Well the good news is that replacing the caps has eliminated the hum and restored my v1 MFW to working order. The one odd thing is that it is now requiring significantly higher gain both from my pre-amp's out and at the subwoofer's amp in order to match my other existing non cap fixed v1 MFW. 12 db more at the pre-amp (which I am not worried about at all) and 25% more on the pot on the MFW.

 

I don't know if that was to be expected with the caps that were installed (I ordered the exact parts from parts express as recommended way earlier in this thread). I hope running the higher gain doesn't shorten the life of the unit by having it run hotter.

post #2556 of 2590
What input are you using in the amp. If you are using the l or r instead of lfe it would make sense
post #2557 of 2590
Quote:
Originally Posted by Suburban1 View Post

What input are you using in the amp. If you are using the l or r instead of lfe it would make sense

I have two sw outs from the pre-amp. Both are plugged into the R input of the two MFW's. I had previously balanced the subs before the one started humming. After the repair, I plugged it in the same exact way, using the exact same settings and noticed low output from the repaired sub. So I then went about balancing with the test tones and came up with what I stated above.

post #2558 of 2590
Quote:
Originally Posted by KenV99 View Post

Quote:
Originally Posted by Suburban1 View Post

What input are you using in the amp. If you are using the l or r instead of lfe it would make sense
I have two sw outs from the pre-amp. Both are plugged into the R input of the two MFW's. I had previously balanced the subs before the one started humming. After the repair, I plugged it in the same exact way, using the exact same settings and noticed low output from the repaired sub. So I then went about balancing with the test tones and came up with what I stated above.

The capacitor fix would not cause such a difference. If it's a V3 version it would have lower gain than the earlier models. Others are more familiar than myself with the identifying markings. The only other thing I could think of is if one of the capacitor fixes was not done properly and only 1/2 the power supply was functioning properly, as that could still run all the front end electronics. Make sure the moderate level output sounds the same as the other amp without extra distortion or "clicking" in the sound output.
post #2559 of 2590

Thankfully the quality of the sound of the output is just fine at moderate levels - the only difference is the volume. To test, I switched around things to make my floorstanding speakers 'small' to send more of the bass to the subs and played some Bach church organ pieces and the tonality and quality are just fine through the fixed amp. I'll pull the board out and check the onboard connections to see if there is a disruption from the soldering sometime in the next couple of days.

post #2560 of 2590
Well, a year or so after doing the capacitor fix to resolve my hum issue, now I'm getting a new problem.

The sub makes a crackling sound or almost like it's under water when it has power and is on.

I pulled out the amp power board and the 4 capacitors look okay. Nothing is bulging or anything. Should I swap them again anyway or is this something different, more difficult to fix?
post #2561 of 2590
I sent a PM to Murrel before I got far enough into this thread to read the V3 amps are no longer available.

My theater MFW-15 died a couple years ago... yeah, I kept meaning to "get to it", but the buttkicker and Rocket speakers kept enough that I put it off.

Now I'm finally upgrading my old 720p Panny to the Epson 5030, and I want to "revitalize" my theater.

Does anyone have any replacement V3 amps? I'm now nervous about my downstairs MFW-15 (paired with X-series) - it gets 50x the usage (but lower volume; wife's Top Chef, etc, doesn't stress it) since its hooked to the TV, but has never had any issues. Both were bought at the same time in about 2009.
post #2562 of 2590
Glen long time no see.

Do you know about Sandbagger's options over on Mark's forum? Motor City Custom Audio

I've been pretty lucky I have two working MFW-15's and a spare V1 amp. Sorry I'm not parting with the amp just yet. I think the key to longevity in my case was getting two units from the very first shipment from Sound Arts China (Mr Pu). I think they went to some cheap China manufacturer shortly thereafter for cabinets and electronics in addition of course to those troubled cabinets from Columbia. Once Mr Pu caught on to MLS's ways things went downhill fast.
post #2563 of 2590
Please Help,
From all the posts I've read, I should consider myself lucky that my mfw15 lasted this long (though likely it is b/c it has been used sparingly and easily...HT room took too long to build and mostly watching kids movies)....anyway, a couple days ago I had a movie going (sub had been on around 10 minutes) and all of a sudden it is making a loud HUM:eek:

So, I turned it off (and the hum continued)....
I unplugged the RCA (LFE) input (and the hum continued) ARGH!!
I tried using a power cord w/o a ground and that made no difference.

I had assumed that I had a V2 amp, but when I opened it up I found that the red & black wires leading from the amp to the driver are soldered to the amp.
So, I understand that means it is a V1 amp?
The cabinet says Serie NO:1318 under the amp.
The speaker level input/output pcb says 2.0 2007-5-26

I looked at the capacitors and I 'think' they look OK. One of them may have had the very minimal slightest bit of bulge, though that may be wishful thinking...but not as noticeable as the pics I've seen in the thread.

Even with no audio input connected (LFE input removed) it has a loud hum instantly when it is plugged in, even with the power switch in the off position.

Prior to this I had NEVER had any audible buzz.
If anyone understands what is causing the malfunction in my V1 amp, and has a cost effective solution, I'd be VERY grateful!!
(btw...when I removed the amp, I didn't find the 'fuses' that some posts had referred to, but I'm guessing that fuses wouldn't be the issue the way mine is acting anyway?)

Thank you in advance for any wisdom!
post #2564 of 2590
jkagsl,

Sorry it seems your post has been ignored.



Did you end up performing the cap fix? Its not that it will not work on the V1 amps.....V1 amps had some other issues in the output board that caused a hum.

Post 2513 is where you can download the instructions. order the parts from Parts Express. Find a local TV shop to do the work.




Just remember....lots of great subs out there in the 500USD range and most come with a warranty and some peace of mind!



Good luck!

Murrel
post #2565 of 2590
Murrel,
Thank you so much for a response. I am currently using my (very) old Advent 10" powered sub which I pulled out of retirement, and it is a sorry replacement for the MFW15.
If you think that the characteristics of my 'hum' (that it is loud and starts as soon as it is plugged into AC power, even if turned off with no input) are such that it may be attributable to the capacitors, I will definitely pick up those four from PE and give it a shot.
I don't solder the best, but I think I'll include a solder braid in my PE order and I can do it. I didn't really notice any significant bulge on any of the four caps of interest, but for the cost of parts, it is definitely worth a shot if you think it may work.
I had thought that my 'hum' which is pretty loud and is present even with the amp turned off seemed like maybe it was acting different than others who the fix had worked for.
I appreciate the replacement suggestion also and I've decided that if the fix doesn't work, I'll likely purchase an external subwoofer amp for it.
Your knowledge is much appreciated!
Jason
post #2566 of 2590
FWIW... Murrel has forgotten more about the MFW amps then most people will ever know, so whatever he tells you is pretty much a certainty. The only thing he knows about more than those amps is beer! tongue.gif
post #2567 of 2590
Can someone point me to where it can be determined which Version I have. It has worked as intended for several years. I believe I purchased some time during 08-09. Turned it on this morning and the hum started. I unplugged the cable and it still hummed. IT doesn't hum when the auto on is red and it is not receiving a signal, but as soon as the receiver kicks on the hum starts.

To remedy do I first need to determine the version? Whats next?

Any help is greatly appreciated. I would consider the tubo down the road, but it is not currently a financial option and I don't know if they are even available.
post #2568 of 2590
If the driver leads are soldered to the amp board its a V1

If they connect via spade to the board its V2

Also i know the V2 amps have V2 printed on the amp board.

Also if your serial number(amp) starts with LT i think its V2
post #2569 of 2590
I have a V1 then. Suggestions on how to proceed, I have been reading though this thread, but it is really long.
post #2570 of 2590
Do the cap mod and start saving for a replacement amp or the turbo kit.
post #2571 of 2590
Anyone have any experience with this mod or can recommend someone in Cincinnati?
post #2572 of 2590
Any good TV place should be able to do it for cheep if you take the amp out , take it to them with the instructions and say, just follow this, dont test or anything else. just plug in the new caps.
Quote:
Originally Posted by dsully444 View Post

Anyone have any experience with this mod or can recommend someone in Cincinnati?
post #2573 of 2590
FWIW...For others who are reading this thread in search of answers due to the unfortunate demise of their MFW-15 amps, I am adding on some additional info.
Murrel had sent me a PM that since my MFW's loud hum is present even with the power turned off, that my amp is probably 'done'.
He said he'd seen a couple others like mine and he was not able to fix them. If he can't fix it, I can't either, so I'm now in the market for a new amp.
post #2574 of 2590
If anyone is still viewing this old thread, do you know if this plate amp from Parts Express would work with the stock driver?
http://www.parts-express.com/dayton-audio-spa1000-1000w-subwoofer-plate-amplifier--300-809
I realize that 1000 watts is more than the stock driver needs or really wants, but would i be OK as long as I don't crank the gain?
It is only about $50 more than the 500 watt version and I am kinda thinking about doing a custom box with two more power-hungry 10 drivers when the factory driver wears out.
Anybody know if it would work well with the MFW's 15??
Thanks in advance!
post #2575 of 2590
Quote:
Originally Posted by jkagsl View Post

If anyone is still viewing this old thread, do you know if this plate amp from Parts Express would work with the stock driver?
http://www.parts-express.com/dayton-audio-spa1000-1000w-subwoofer-plate-amplifier--300-809
I realize that 1000 watts is more than the stock driver needs or really wants, but would i be OK as long as I don't crank the gain?
It is only about $50 more than the 500 watt version and I am kinda thinking about doing a custom box with two more power-hungry 10 drivers when the factory driver wears out.
Anybody know if it would work well with the MFW's 15??
Thanks in advance!

I'd stick with the 500 watt version, unless you plan to upgrade later. My amp died last year in the same fashion as yours, humming present. I did the cap replacement and that didn't make a difference either, so yeah, it's "done" lol. I'm currently using a Crown XLS 1500 that pushes 525 watts at 4ohms from a single channel (also using a Behringer MIC2200 as a line driver and high-pass filter at 18 hz). As this amp will push 1550 watts bridged at 4ohms, I'm considering replacing the MFW-15 Driver with this driver (http://store.ficaraudio.com/q15/) or just selling the amp and going with the Turbo kit. I'm not fully decided either way. Since I already have the amp, it's cheaper for me to just upgrade the driver, but otherwise a turbo is really tempting since it comes pre-EQed and made to match the MFW-15 enclosure.
post #2576 of 2590
Can anybody comment on how the turbo kit would fare against another 800 dollar sub like the PSA XV15 or SVS PB2000 or other subs in that category ?

I LOVE my piano black cabinets, so i lean the turbo direction but i want to have GREAT bass still....

Thoughts?
Anybody point me in the direction of measurements for the stock mfw, and the turbo ?

Thanks!
post #2577 of 2590
Quote:
Originally Posted by fst96se View Post

Can anybody comment on how the turbo kit would fare against another 800 dollar sub like the PSA XV15 or SVS PB2000 or other subs in that category ?

I LOVE my piano black cabinets, so i lean the turbo direction but i want to have GREAT bass still....

Thoughts?
Anybody point me in the direction of measurements for the stock mfw, and the turbo ?

Thanks!

All of the reviews I have been able to find on the MFW-15 Turbo seem to put it on par with a much more expensive sub than anything in the $800 range, think SVS PB12-Plus or even PB13-Ultra. The sheer SPL of the turbo is equal or greater than two vanilla MFWs, and the response graphs show flat, tight base response. Since the PB2000 is a sealed 12 with only 500 watts RMS, you can be assured that the turbo will still out perform that middle-market cube. I don't know much about the PSA XV15 but looking at the specs it looks like a solid performer too. I'd still predict the turbo to outperform due to twice as much power and seemingly better driver.

Here's the Turbo thread with details on it: http://www.seaton-sound-forum.com/post/mfw15-turbo-upgrade-5986296?&trail=20
post #2578 of 2590
Micah,
I appreciate your suggestion. Yes, I do intend to upgrade at a later time, but I was curious if the SPA1000 would work with the factory driver for a couple years or so, until I had the funds to buy a couple of 10's, something like these:
http://www.parts-express.com/dayton-audio-um10-22-10-ultimax-dvc-subwoofer-2-ohms-per-coil--295-510

I just didn't want to have to buy another amp at that time.
My only concern was if I'd be OK with the SPA1000 amp, as long as I didn't crank it too much, say not over 40% gain or so?
Or would I just obliterate the factory MFW-15 driver???

I apologize for the Noob question, but I admit, I don't understand ohms and the like as I should.
Thanks in advance for any direction,
Jason
post #2579 of 2590
Quote:
Originally Posted by jkagsl View Post

Micah,
I appreciate your suggestion. Yes, I do intend to upgrade at a later time, but I was curious if the SPA1000 would work with the factory driver for a couple years or so, until I had the funds to buy a couple of 10's, something like these:
http://www.parts-express.com/dayton-audio-um10-22-10-ultimax-dvc-subwoofer-2-ohms-per-coil--295-510

I just didn't want to have to buy another amp at that time.
My only concern was if I'd be OK with the SPA1000 amp, as long as I didn't crank it too much, say not over 40% gain or so?
Or would I just obliterate the factory MFW-15 driver???

I apologize for the Noob question, but I admit, I don't understand ohms and the like as I should.
Thanks in advance for any direction,
Jason

So long as you don't over push it you'll be fine. Be sure to set the high-pass filter at around 18 hertz to make sure LFE content doesn't over extend the driver.
post #2580 of 2590
Quote:
Originally Posted by fst96se View Post

Can anybody comment on how the turbo kit would fare against another 800 dollar sub like the PSA XV15 or SVS PB2000 or other subs in that category ?

I LOVE my piano black cabinets, so i lean the turbo direction but i want to have GREAT bass still....

Thoughts?
Anybody point me in the direction of measurements for the stock mfw, and the turbo ?

Thanks!
I haven't looked at this thread in a while, thus my late reply...but hope it helps in any decisions.

I've been a Turbo owner going on three years now (wow, how time flies!), and can confidently say that the Turbo should run circles around any $800 sub. The bass output is just amazing, and am a bit surprised that I haven't seen any drywall cracks when I really crank 'er up. wink.gif I'd recommend the Turbo kit to anyone in the market for one, without hesitation. I also had some comments about what to watch for when installing the new driver, which is this post over on Seaton's forum mentioned above.

When my stock amp died in Feb 2011, I was considering the PB13 Ultra and was lucky enough to contact some local Forum members who graciously allowed me to demo them in their homes. After weighing the pros and cons between the SVS and Turbo, I ended up buying the Turbo kit, primarily as the kit cost considerably less than a new PB13. Plus I really liked the look of my MFW's Cherry Rosa cabinet, same as you and your piano black ones. After living with the Turbo, I think it would perform quite respectably against the PB13s that I had demo'ed, though can't remember which amps the PB13s had. I'm sure the PB13 would have the overall performance edge, but I have never regretted the Turbo purchase, ever.

Whatever sub you ultimately buy, I'd recommend you also consider a dedicated sub EQ to make sure it's calibrated properly for your room. I have a Velodyne SMS-1 that's been used with both the stock MFW and the Turbo, and it flattens the response curve quite well to help minimize any large peaks or nulls in the room. The Turbo/Velodyne was last calibrated by AccuCal (look up "umr") last May, and it's never sounded better...well, maybe it'll be even better this May when AccuCal comes back to fine-tune the entire system.

If I could find a second MFW cabinet in cherry to match my current sub, I'd seriously consider buying it and another Turbo kit for my media room.
Edited by mak99 - 2/18/14 at 7:26pm
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