NEW MFW-15 amps (May 2010) *pics* - Page 73

Anytime after 8am MST is fine

Murrel

No more V3s?

Nick

I have run out of transformers and back plates. Both are expensive in small quantities.

So yes the V3 amp production is over.

Hope all is well with you!

Murrel

Hi murrel,

All is well here!

Do you have any other hard parts left over? ive got some V2 parts(back plate/transformer) and might be interested in buying them to frankenstein a V3?

Nicholas

Nick,

As you know I have other products that I build. The hard parts (boards) all are used in those products. It is just the V3 that I am not building anymore. It would be mush easier for me to just sell you a amp that you could build a box for. Trying to place the new boards on the old plate would require new holes to be drilled and leave you with holes you would need to fill. Plus there are some wiring mods to the transformer to make it work properly.

Have a great day!
Murrel

Guess I need to get back into figuring out an amp solution for the MFW's

Gotcha, Just Checking..... I love to tinker.

I have a working ULW10 I'll trade for a version 3 amp

Sorry about my English.

I dont think there was a serious problem with V2 amp.According to Murrel,I replaced 4 capacitors with higher voltage rate capacitors and everything is back to normal.Hump is still there but it was reduced a lot.In my opinion,the V2 amp has a better quality than V3.

To people who is using V2 amp,I want to shared something I did to improve my v2 amp.After playing around with my V2,I did a test with the power supply board.I set the volume to 1 oclock and played "3 types of bass " song.I used a mulimeter to measure the voltage drop beetween 4 capacitors.At the deepest bass note in the song(about 3 seconds), the voltage droped down from 75v to 68v.

At that time,the output of the MFW15 was funny(strange noise appeared) and the bass was like uncontrolled.By doing that I know the power board did not provide enough power for the amplifier module-->distortion.I looked at the values of 4 no name filter capacitors on power supply board(1500uf each,3000uf for each channel) which are way too small.I think to reduce the cost of the amplifiers,they chose to use no name low value capacitors.

So i bought 4 3300uf 100v nichicon capacitors from digikey to connect to 4 originals capacitor in parallel.The total capacitance at this time is ~10000uf for each channel. Doing a test again(volume was set to 1 oclock),now the voltage droped down from 75v to 72.5 at deepest note in the song.Moreover,the MFw15 now not only can shake my wall but also shake my couch freaking hard which I could not feel before.My wife sat next to me on the couch also felt that . The output at the hardest note is clean and very stable.In addition, is the hump now is barely heard (deadly silent). Im really impressed with the MFW 15 after adding more capacitor.





I also replaced the red cheap output capacitor on the audio board with a 3.3uf 400v Jentsen audio cross cap which makes the output now is not muddy at before but faster and more musical.I am not an audiophile but I can hear the difference.



I also move all the wires(from controller and driver) far away the transformer.The electromagnetic from transformer will interfere with the audio signal,which caused hump.Those people who still get hump after replacing 4 caps should check this.

In conclusion,the total cost for this upgrade is under 30 bucks and it makes a huge different in sound quality.In the future,I may add more capacitors for the power board to make less voltage drop as much as possible.
Disclaimer: I will NOT be held responsible for you damaging your amplifier. I am not responsible of you get hurt.Do it at your own risk.Do NOT try this at home.It should be performed by a professional.

Great idea, superbabyboy. I have 2 mfw-15's with v3 amps. The v2's I took out have been hum-fixed and work great. I've been thinking of selling them, but haven't gotten around to it yet. I am in agreement that the v2's have a slight edge in sound quality, but they run hot, even in standby. They had me worried enough that I bought v3's. The v3's are lukewarm at most.

Do you think there is a circuit change that could cause the v2 transformer to run cooler? If so, I might sell my v3's and keep modified v2's.

The capacitor swap is genius.

V3 Question, Power:
Down=OFF
Middle=AUTO
Up=ALWAYS ON

Is that correct & what is the recommended position?

HH

HH

That is correct. Personally I leave mine on. But that is just me.

Murrel

It is not capacitor swap.I just added more capacitance for the power module so the subwoofer can play more stable at its peak output.

The power transformer is supposed to be hot after using for a while.The only thing to make it cooler is take it outside and run wires back into the cabinet.Just leave it in the cabinet,i think it is just fine.You dont have to worry about it too much.

Version 3 amp needed here

Same here ... this sucks!

Any updates on the Turbo kit?

Also need V3 amps (2).

Im from South-africa is it possible to get a v3 amp to me? my amp is shutting down if i turn volume past 1/4 for 5mins. Can't i modify parts so it would run cooler?

Thanks

make a cheaper turbo kit

That would be called an amp solution.

Good news is I should have the new driver to test next week
I have seen the manufactures test measurements and things look real nice(as expected too)

Murrel please give me some pointers as to what i can do with my amp for the heat problem, i dont care if i leave extra holes in the plate so long it plays with less heat It says on one of the pcb's mfw-15_powr v2.1 so i can probably assume its a v2 amp? Im handy with a soldering iron so any ideas would be much appreciated.

Also could it be my soundcard input signal thats too much to the mfw's LFE because main volume is at 100% on my asus xonar essence st sound card... because i notice the driver almost cant even handle half volume on the v2 amp and wow is that transformer hot even when the amp is on standby...

Sorry for asking such irritating questions but thanks for listening.

Intuition667

I did not want you to think I was ignoring you. I an on Vacation and will reply to you when I get home.

I do think that running the input hot will affect the sound and possibly the heat generated. But the V1 and V2 amps should NEVER be run at more than about 11:30 on the dial.


Murrel

I see, Thanks

Hoping to hear from you soon also anyone else on the thread

ahhhhhh SH!T! I was in negotiations to buy another pair of MFW15's and was going to drop two more V3 amps in them and now I see this!
CRAP!
And I am one who disagrees about the V2 sounding better than the V3. I also have quite a few parts from my franken V2 project left. Including two of the top cross over pieces now that sandbagger finally got me some plates for there!

See what? What did you see that makes you question buying the MFWs? I don't hear a difference in the V2 and V3, but I have heard people say they hear one being better than the other.

I think he means no more V3s.

See that the v3 amps are no longer available. I have had the v1, v2 and the v3. TO ME, I much prefer the control and sound of the v3 versus the other two. Not to mention that the v3 has been pretty much bulletproof in operation. Yes, the V2 might have had more output but it could easily overdrive the sub and damage the woofer.
Once again, my opinion. And this is with having had the cap fixed replacement on the V2 done as well.


and I see Nick and I were posting at the same time... :-)

My V2 needs cap fix. got the parts last month, yet to find time to fix them. Would be nice if V3 is still available. I see that Nick, Steve, themonk, vision and Intuition are also looking for V3s. Hope there are few more requests to justify a second batch for V3s :-)

If turbo kits ever arrive in a decent quantity, V3 will be out there.

Better chance of monkeys flying out of my butt, just sayin' :P