Replace Amp on MFW-15

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friendswithdave

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Re: Replace Amp on MFW-15
« Reply #20 on: 13 Nov 2020, 07:09 pm »
The answer is YES. Just sold for $200 a day after listing on Facebook Marketplace.

louky

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Re: Replace Amp on MFW-15
« Reply #21 on: 15 Nov 2020, 09:18 pm »
Don't replace one cheap plate amp with another cheap plate amp. Instead, buy this one: 

https://www.parts-express.com/dayton-audio-sa230-230w-subwoofer-amplifier--300-813?gclid=CjwKCAiA4o79BRBvEiwAjteoYDUEpgY7I4boxoepoBzVE9cymusFip23T7Yy5bQSuA5jgG_V_LgXXBoCu9AQAvD_BwE

I own an MFW-15 and my amp went bad many years ago. I replaced it with the one linked above. Far superior in sound and much higher build quality.


I have two mfw15, one is in my basement dead. The other still technically works, but makes weird noise now and the hum fix has already been done. Interested in the extenal alternative mentioned. How long are the speaker wires once you pull them out? Do you just sit the external amp on the mfw or is in in your rack/stand or what?
« Last Edit: 16 Nov 2020, 12:58 am by louky »

louky

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Re: Replace Amp on MFW-15
« Reply #22 on: 15 Nov 2020, 10:26 pm »
I have been having trouble identifying and finding the exact capacitors required. I'm leaning towards replacing the entire amp or selling it as is. Is there a market for these subs with bad amps?

Think I got them from parts express years ago


https://www.reddit.com/r/audio/comments/4qvoqk/av123_mfw15_humming_fix/?utm_medium=android_app&utm_source=share




Doublej

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Re: Replace Amp on MFW-15
« Reply #23 on: 16 Nov 2020, 02:41 am »

I have two mfw15, one is in my basement dead. The other still technically works, but makes weird noise now and the hum fix has already been done. Interested in the extenal alternative mentioned. How long are the speaker wires once you pull them out? Do you just sit the external amp on the mfw or is in in your rack/stand or what?


One elegant way to do it is to put a pair of speaker binding posts on the back of the plate amplifier. I would first see if they would fit in the holes where the RCA jacks are. Once you have found a place for them and have mounted them on the plate, connect the subwoofer driver to the speaker binding posts by removing the two wires connecting the driver to the circuit board and then soldering these wires to the speaker binding posts.

Now you have a connection like you do on the back of a pair of speakers. Use your favorite speaker wire of the length required based on where you put the subwoofer amplifiers. I think it looks cleaner to keep the amps in a rack than it does to keep them on top of the subwoofers.






Early B.

Re: Replace Amp on MFW-15
« Reply #24 on: 16 Nov 2020, 04:40 am »

I have two mfw15, one is in my basement dead. The other still technically works, but makes weird noise now and the hum fix has already been done. Interested in the extenal alternative mentioned. How long are the speaker wires once you pull them out? Do you just sit the external amp on the mfw or is in in your rack/stand or what?

My sub amp sits on top of the MFW. I've also laid the amp on its side to hide behind or on the side of the sub. It doesn't get hot at all. The speaker cables are only 2 - 3 feet long. Once you dial in the sub, there's no need to touch it again. It turns itself on and off.

louky

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Re: Replace Amp on MFW-15
« Reply #25 on: 16 Nov 2020, 01:25 pm »
My sub amp sits on top of the MFW. I've also laid the amp on its side to hide behind or on the side of the sub. It doesn't get hot at all. The speaker cables are only 2 - 3 feet long. Once you dial in the sub, there's no need to touch it again. It turns itself on and off.

I know you already answered that the sa230 is plenty of power, but what about if I eventually wanted to go back to 2 mfw15? I use to split the signal and use both, but just one huge box  is pushing it now with wife approval required. Lol. Guessing I'd need to step up to something like the sa1000 or is the 230 still sufficient?


For anyone else considering the sa230, parts express has a promo code right now for $20 off making it $199 thru 11/18 looks like.

Early B.

Re: Replace Amp on MFW-15
« Reply #26 on: 16 Nov 2020, 02:21 pm »
I know you already answered that the sa230 is plenty of power, but what about if I eventually wanted to go back to 2 mfw15? I use to split the signal and use both, but just one huge box  is pushing it now with wife approval required. Lol. Guessing I'd need to step up to something like the sa1000 or is the 230 still sufficient?

You would need an SA230 for each sub.

louky

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Re: Replace Amp on MFW-15
« Reply #27 on: 19 Nov 2020, 08:24 pm »
You would need an SA230 for each sub.

Back in business with the sa230. Plenty of power like you said.Only issue I had is the speaker cables only seem to be about a foot long. I pulled until it seemed difficult and didn't want to damage anything.  So basically just propping it on the back wall for now until I look into the possibility of splicing it. Not sure if that's possible, but I'd like to be able to reach my tv stand. Anyway, thanks for sharing the info here.

Early B.

Re: Replace Amp on MFW-15
« Reply #28 on: 19 Nov 2020, 09:12 pm »
Back in business with the sa230. Plenty of power like you said.Only issue I had is the speaker cables only seem to be about a foot long. I pulled until it seemed difficult and didn't want to damage anything.  So basically just propping it on the back wall for now until I look into the possibility of splicing it. Not sure if that's possible, but I'd like to be able to reach my tv stand. Anyway, thanks for sharing the info here.

You can either replace the speaker cable altogether or splice it and make it as long as you need.   

musicmaniac

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Re: Replace Amp on MFW-15
« Reply #29 on: 23 Nov 2020, 12:47 pm »
Don't replace one cheap plate amp with another cheap plate amp. Instead, buy this one: 

https://www.parts-express.com/dayton-audio-sa230-230w-subwoofer-amplifier--300-813?gclid=CjwKCAiA4o79BRBvEiwAjteoYDUEpgY7I4boxoepoBzVE9cymusFip23T7Yy5bQSuA5jgG_V_LgXXBoCu9AQAvD_BwE

I own an MFW-15 and my amp went bad many years ago. I replaced it with the one linked above. Far superior in sound and much higher build quality.
My MFW-15 finally went and I'm thinking of trying your solution. I've never used an external amp before and just used the LFE. Is there anything a novice like me has to worry about setting this amp up? Thanks for any input you can provide.

Early B.

Re: Replace Amp on MFW-15
« Reply #30 on: 23 Nov 2020, 03:18 pm »
My MFW-15 finally went and I'm thinking of trying your solution. I've never used an external amp before and just used the LFE. Is there anything a novice like me has to worry about setting this amp up? Thanks for any input you can provide.

Very simple. Read Reply #8 in this thread.

musicmaniac

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Re: Replace Amp on MFW-15
« Reply #31 on: 23 Nov 2020, 10:22 pm »
Thanks, I can't believe it's that simple. I just ordered one and look forward to having my boom back this weekend!

genjamon

Re: Replace Amp on MFW-15
« Reply #32 on: 24 Nov 2020, 02:36 am »
I replaced my busted amp several years ago with Seaton Sound's new replacement amp, with quite an improvement in sound.  Seaton loads a custom EQ curve into the amp, based on the particular characteristics of the woofer.  I had him load the original woofer profile, since I still have the original woofer (had been waiting for Seaton to finish designing his newer Turbo woofer that would fit my Rosewood cabinet baffle, but he has never finished that project to my knowledge).  So, I've just been enjoying the new amp with the original woofer these years.  But have always desired to upgrade woofer.

Ok, my question is how much you guys think going with that Dayton upgraded woofer might compromise the sound if I have a Seaton amplifier with EQ based on the original woofer.  I know I should just ask Seaton Sound, and I'll likely do so, but thought I'd see what you folks have to say about it. 

Early B.

Re: Replace Amp on MFW-15
« Reply #33 on: 24 Nov 2020, 05:41 am »
Ok, my question is how much you guys think going with that Dayton upgraded woofer might compromise the sound if I have a Seaton amplifier with EQ based on the original woofer.  I know I should just ask Seaton Sound, and I'll likely do so, but thought I'd see what you folks have to say about it.

I think you already know the answer. What I will say is that the Dayton woofer will be a substantial upgrade. 

chinchy

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Re: Replace Amp on MFW-15
« Reply #34 on: 15 Jan 2021, 08:27 am »
I haven't touched my sub in years, and tried turning it on, and it has the hum.  I tried looking for the replacement capacitors, but there are a ton of choices and sizes and brands.  Does anyone know the exact specs (including diameter/height) that will work to fix the amp?  I tried checking the Seaton Sound for the replacement amp/woofer, but it doesn't look like it's been in stock for a while and I haven't gotten any email response.  And since I'm new, I can't send PMs or get profile information to contact members yet.  Any help would be great, thanks!

iteachsteam

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Re: Replace Amp on MFW-15
« Reply #35 on: 21 Dec 2021, 01:33 pm »
Hello all,

I know this is a little older, but I just joined the ranks of an AV123 MFW-15 owner.  Of course the amp was toast, and I don't feel like repairing a mediocre onboard amp.  So, I am going to run it off of a Crown K2 like I do with my current home theater system with great results. 

However, I am chime in here because I noticed parts express just came out with a new woofer that might be a good solution for upgrading the driver. It's supposed to work well in a 4 sq.ft. ported enclose. https://www.parts-express.com/Dayton-Audio-RSS390HE-22-15-Reference-Series-High-Excursion-Subwoofer-22-ohm-295-292  I thought I would share this in case someone wants to try it out.

I currently use two 15"  RSS390HF-4 15" Reference HF Subwoofers in sealed enclosures for my 2.2 music system, and I think they are decent, especially when considering the cost.

genjamon

Re: Replace Amp on MFW-15
« Reply #36 on: 21 Dec 2021, 05:49 pm »
It does look interesting, and has lower extension in a vented enclosure than the 15" HO reference sub driver.  However, it states the ideal volume for a vented enclosure as 4 cuft, but the MFW-15 cabinet is more like 3 cuft.  How would that smaller volume impact compatibility?