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NEW MFW-15 amps (May 2010) *pics* - Page 75

post #2221 of 2481
4/19/12 at 5:31am
I did the cap fix on my V2 a while back and it worked well but now I am also getting the crackling noise. It is heat-related and sounds like a bad transistor. When I get a chance to troubleshoot I will post the results.

The best bet for most people with bad amps at this point would probably be to get an outboard amp and be done with it. At least until a turbo option is available. I happen to have some extra pro amps lying around, so I will probably just go that route as well.
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post #2222 of 2481
4/19/12 at 5:37am
i have an early mfw 15 just started to get hum when it warms up will capacitor fix work for early v1 amps?
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post #2223 of 2481
4/19/12 at 9:06am
Quote:
Originally Posted by ericsilv View Post

i have an early mfw 15 just started to get hum when it warms up will capacitor fix work for early v1 amps?

It's worth a shot. But to be honest with you the success rate is pretty low on V1 amps.


Murrel
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post #2224 of 2481
4/19/12 at 9:09am
Quote:
Originally Posted by ericsilv View Post

i have an early mfw 15 just started to get hum when it warms up will capacitor fix work for early v1 amps?

Here is a V2 on ebay with the cap fix

http://www.ebay.com/itm/MFW-15-v2-Su...#ht_1291wt_932

Murrel
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post #2225 of 2481
4/19/12 at 1:52pm
tnx for response amp is sold on ebay i assume capacitors are same values as in ver 2 amp i had one of the early production run amps never had problem till now
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post #2226 of 2481
4/19/12 at 2:31pm
Quote:
Originally Posted by ericsilv View Post

tnx for response amp is sold on ebay i assume capacitors are same values as in ver 2 amp i had one of the early production run amps never had problem till now

Yes the power supply boards were the same in the V1 and V2
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post #2227 of 2481
4/28/12 at 10:20am
Hello. It has been a very long time since I've visited this thread. Thursday night I was watching a movie, Moneyball (which has no low end bass), when I started to hear a humming noise coming from my MFW15. I turned it off and on but that of course didn't fix the issue. I started to read the last few pages of this thread and now realize my amp is probably the issue.

I will have to take a look at mine tonight to verify what amp version I have. How do I tell what version my amp is? Is there a way of getting it repaired or geting a replacement?

My MFW15 has worked perfectly since the day I received it. I guess my luck has run out.
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post #2228 of 2481
4/28/12 at 10:24am
Quote:
Originally Posted by beekermartin View Post

Hello. It has been a very long time since I've visited this thread. Thursday night I was watching a movie, Moneyball (which has no low end bass), when I started to hear a humming noise coming from my MFW15. I turned it off and on but that of course didn't fix the issue. I started to read the last few pages of this thread and now realize my amp is probably the issue.

I will have to take a look at mine tonight to verify what amp version I have. How do I tell what version my amp is? Is there a way of getting it repaired or geting a replacement?

My MFW15 has worked perfectly since the day I received it. I guess my luck has run out.

beekermartin,

V1 amps have the driver leads soldered to the output board
V2 amps have the driver leads connected with spade lugs.

In my sig is a link to the hum fix document.

Let me know if you need any help.

Murrel
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post #2229 of 2481
4/28/12 at 10:48am
I will take a look at my amp when I get home and post again. I know it is not a V3. I got my MFW15 before the V3 was introduced.

I took a look at your website. I am far from an expert when it comes to electronics. I can handle soldering a bit but what your site shows it probably a bit out of my ability range. Is this something I could have repaired locally? Do you repair them?
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post #2230 of 2481
4/29/12 at 6:32am
Quote:
Originally Posted by beekermartin View Post

I will take a look at my amp when I get home and post again. I know it is not a V3. I got my MFW15 before the V3 was introduced.

I took a look at your website. I am far from an expert when it comes to electronics. I can handle soldering a bit but what your site shows it probably a bit out of my ability range. Is this something I could have repaired locally? Do you repair them?

Any local repair shop can do it for a few bucks....
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post #2231 of 2481
4/29/12 at 5:58pm
I removed my amp tonight. It appears I have the V2 since the wires going to the driver are connected via spade lugs. Also the board with the giant capacitors on it says V2.1 and the board next to it says V2.2.

I am going to order the capacitors from Partsexpress and try to replace them myself. If I can't do it I'll bring it to local shop. If they won't do it I'll send it to Murrel. Hopefully replacing the capacitors fixes the hum. I have been really happy with the MFW-15 and I don't feel like looking for a replacement anytime soon.
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post #2232 of 2481
5/1/12 at 6:56am
I removed the power board from the amp this morning. It looks fairly simple to replace the capacitors. I am going to order them today and give it a go.
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post #2233 of 2481
5/1/12 at 7:02am
I do have one question though. What is the white paste on the part that touches the amp plate? It looks like thermal compound that is used between heatsinks on computer parts. If you look at the picture on Murrel's site it is the flat, black part in the upper right hand corner. It touches the amp plate and there is compound on the plate and that part.
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post #2234 of 2481
5/1/12 at 7:15am
Sorry. I just ran into another question. There are two types of 470uF 35V on partsexpress. http://www.parts-express.com/wizards...lter=470uf+35v

I am assuming the high temp one is the correct one since Murrel's site states they cost @.39 each.

Same issue with the 1000uF 35v. http://www.parts-express.com/wizards...+35v&x=15&y=10

I also assume the high temp version is the correct one for the 1000uF 35v as well.
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post #2235 of 2481
5/1/12 at 10:34am
Quote:
Originally Posted by beekermartin View Post

Sorry. I just ran into another question. There are two types of 470uF 35V on partsexpress. http://www.parts-express.com/wizards...lter=470uf+35v

I am assuming the high temp one is the correct one since Murrel's site states they cost @.39 each.

Same issue with the 1000uF 35v. http://www.parts-express.com/wizards...+35v&x=15&y=10

I also assume the high temp version is the correct one for the 1000uF 35v as well.

digikey is a better place to buy capcitors than partexpress.Their shipping cost is cheap too.The Lelon capacitors from partexpress are cheap low quality Chinese capacitors .
You should buy capacitors from Panasonic,Nichicon or Elna.Go to 50v if you can.higher voltage is better.I used 50v Elna capacitors for my circuit.
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post #2236 of 2481
5/1/12 at 11:43am
Quote:
Originally Posted by beekermartin View Post

Sorry. I just ran into another question. There are two types of 470uF 35V on partsexpress. http://www.parts-express.com/wizards...lter=470uf+35v

I am assuming the high temp one is the correct one since Murrel's site states they cost @.39 each.

Same issue with the 1000uF 35v. http://www.parts-express.com/wizards...+35v&x=15&y=10

I also assume the high temp version is the correct one for the 1000uF 35v as well.

beekermartin,

Yes the high temp ones are fine. Out of the 500 or so MFW amps I have personally repaired and the 600 or so that I have had contact with doing their own repairs. I would say 99% have purchased the parts from Parts Express or radio shack.

Yes you could go with 50 volt caps. But in the thousand or so "fixes" i have been involved with no one has ever had the hum return. I have had a few that have damaged a solder barrel (i have a fix for that to) and of course there are the amps that have had the output board failures. So the document and the parts I recommend will work just fine.

If you need help I am just a e-mail or phone call away!

Murrel
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post #2237 of 2481
5/1/12 at 12:38pm
I want to say thank you for your indirect help for the info posted in this thread.

I solved my hum problem plaguing me for the last 1 year by breaking off the ground lead.

No more hum.

Cheers!
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post #2238 of 2481
5/1/12 at 4:02pm
Quote:
Originally Posted by superbabyboy1984 View Post

digikey is a better place to buy capcitors than partexpress.Their shipping cost is cheap too.The Lelon capacitors from partexpress are cheap low quality Chinese capacitors .
You should buy capacitors from Panasonic,Nichicon or Elna.Go to 50v if you can.higher voltage is better.I used 50v Elna capacitors for my circuit.

I am sure your trying to be helpful but you totally confused me. I don't know anything about capacitors or small electronic parts like it. I was about to order them from Partsexpress but now I am not sure if I should. I went on Digikey.com but I am overwhelmed by the amount of choices.

Can someone please tell me what to order so I don't over think this to death??? I usually like to learn all there is to know about something before I get involved with it but I don't have the time to spend on this. I enjoy home theater equipment but I have no intentions of developing my own line of amplifiers!

I don't mind spending more for better quality but I don't know what that is!
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post #2239 of 2481
5/1/12 at 4:07pm
Quote:
Originally Posted by beekermartin View Post

I am sure your trying to be helpful but you totally confused me. I don't know anything about capacitors or small electronic parts like it. I was about to order them from Partsexpress but now I am not sure if I should. I went on Digikey.com but I am overwhelmed by the amount of choices.

Can someone please tell me what to order so I don't over think this to death??? I usually like to learn all there is to know about something before I get involved with it but I don't have the time to spend on this. I enjoy home theater equipment but I have no intentions of developing my own line of amplifiers!

I don't mind spending more for better quality but I don't know what that is!

beekermartin,

That was the whole idea with the hum fix. For it to be simple. Just purchase the high temp parts that I spec'ed from Parts Express. No need to think about it.

Read post 2236 above.
Murrel
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post #2240 of 2481
5/1/12 at 4:46pm
I ordered them from Partsexpress. The 22uF 160v was only available in "normal" temp so that is what I got. http://www.parts-express.com/pe/show...TR=22uf%20160v

Thanks again Murrel! It is very nice of you to help out like this. If replacing the caps fixes the hum I'll be sure to send you a few buck via paypal!
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post #2241 of 2481
5/1/12 at 4:54pm
Quote:
Originally Posted by beekermartin View Post

I ordered them from Partsexpress. The 22uF 160v was only available in "normal" temp so that is what I got. http://www.parts-express.com/pe/show...TR=22uf%20160v

Thanks again Murrel! It is very nice of you to help out like this. If replacing the caps fixes the hum I'll be sure to send you a few buck via paypal!

beekermartin,

The parts you ordered will do just fine! No payment necessary! I apreiciate the thought and the thanks!

Murrel
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post #2242 of 2481
5/1/12 at 7:03pm
Thanks again Murrel. I'll post again after I've installed the new capacitors.

Should apply some thermal paste on the part that contacts the amp plate? I believe that was what was on it. If so I assume I should use a non conductive type and not arctic silver 5 for example.
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post #2243 of 2481
5/1/12 at 7:11pm
Quote:
Originally Posted by beekermartin View Post

Thanks again Murrel. I'll post again after I've installed the new capacitors.

Should apply some thermal paste on the part that contacts the amp plate? I believe that was what was on it. If so I assume I should use a non conductive type and not arctic silver 5 for example.

Just a bit of non conductive thermal paste is fine. It is a coated part so there is nothing that will short out. If there is some left on the plate it should be enough. I believe that you can buy a small tube at Radio Shack if you need to.


Murrel
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post #2244 of 2481
5/1/12 at 7:28pm
I've got plenty. I've been building computers for years. I always use Arctic Silver 5 so I have plenty of tubes of generic stuff that comes with CPU heatsinks. If you ever need help with computer related issues send me a pm. I'll try to repay the favor!
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post #2245 of 2481
5/1/12 at 7:50pm
Quote:
Originally Posted by beekermartin View Post

I've got plenty. I've been building computers for years. I always use Arctic Silver 5 so I have plenty of tubes of generic stuff that comes with CPU heatsinks. If you ever need help with computer related issues send me a pm. I'll try to repay the favor!

Thanks! I may take you up on that offer some day!

Murrel
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post #2246 of 2481
5/1/12 at 8:56pm
The more I compulse on this amp the more questions I think up. I am starting to wonder if my amp is in fact version 2 or version 1. I just found a picture of a v2 amp and I noticed the leads that go to the driver are removable. On mine the leads appear to be soldered to the board and are covered in some type of liquid electrical tape. There are removable connectors where the wires connect to the driver though.

I'll try to post some pics when I get home.
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post #2247 of 2481
5/1/12 at 9:00pm
Quote:
Originally Posted by beekermartin View Post

The more I compulse on this amp the more questions I think up. I am starting to wonder if my amp is in fact version 2 or version 1. I just found a picture of a v2 amp and I noticed the leads that go to the driver are removable. On mine the leads appear to be soldered to the board and are covered in some type of liquid electrical tape. There are removable connectors where the wires connect to the driver though.

I'll try to post some pics when I get home.

That sounds like a V1 amp. Post some pics later or email them to me. V1 amps have a much lower success rate when it comes to fixing the hum. Send me pics of the power supply board also so I can take a look at the capacitors.

Murrel
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post #2248 of 2481
5/1/12 at 9:36pm
I am not sure how to post photos using my Droid. If you wanna pm me your email address I'll send them over.
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post #2249 of 2481
5/2/12 at 12:49pm
Here are a few pics of the amp and power board.
LL
LL
LL
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post #2250 of 2481
5/2/12 at 12:55pm
Quote:
Originally Posted by beekermartin View Post

Here are a few pics of the amp and power board.

That's a V1 amp. From what I can see on my phone at least one of the 470uf caps is bad. Do the hum fix and let me know how it goes.

Murrel
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