Subwoofer Power Supply Problem

[Rusled]

Re: Subwoofer Power Supply Problem

Can't tell you how happy I was to come across this post.
,If, when you power up the ULW 10, with no RCA cord attached, it hums, is the problem the capacitors ?

[japlytic]

Re: Subwoofer Power Supply Problem

Welcome, Rusled!

Is the manufacturer of the subwoofer Onix (according to a Google search)?
And do you have any internal photographs of this subwoofer?

[Rusled]

Re: Subwoofer Power Supply Problem

Welcome, Rusled!

Is the manufacturer of the subwoofer Onix (according to a Google search)?
And do you have any internal photographs of this subwoofer?

Yes it is an Onix purchased from AV123.
I do not have the sub, it belongs to my daughter, so I can't get any pictures for some time.
AV123 has gone out of bussiness. Many owners of this subs are replacing it with a Dayton Plate Amp bought through Parts Express. But at $130 and less power than the OEM, replacing the capacitors sounds like a great fix.

[akuretz]

Re: Subwoofer Power Supply Problem

Great post and great board! I've got the UFW-10 and it's making a horribly loud humming sound (started quiet and got louder), and AV123 (aka Onix) indicated it was a failed capacitor problem. I've opened the amp and the guts are the same as pictured here, the power supply board is even labeled "ULW-10" with the same 1.0 version and date as shown in the OP's pictures.

I've got an electronics/ham radio buddy who has the gear and experience to help me swap these out, but would one of you be willing to post the exact part numbers you ordered to replace all 6 caps on the power supply board?

Also, is there any visual indication of a blown cap? They all look normal to me...

[Wrog]

Re: Subwoofer Power Supply Problem

Great post and great board! I've got the UFW-10 and it's making a horribly loud humming sound (started quiet and got louder), and AV123 (aka Onix) indicated it was a failed capacitor problem. I've opened the amp and the guts are the same as pictured here, the power supply board is even labeled "ULW-10" with the same 1.0 version and date as shown in the OP's pictures.

I've got an electronics/ham radio buddy who has the gear and experience to help me swap these out, but would one of you be willing to post the exact part numbers you ordered to replace all 6 caps on the power supply board?

Also, is there any visual indication of a blown cap? They all look normal to me...

If you posted a list of caps that you have in your sub (uF value, voltage, series, diameter, height), I'm sure someone can recommend replacements. Putting a location in your profile would also be helpful since we have members all over the world, that way someone can suggest a place local to you to order caps from. As for the visual indication, check the photo montage thread! It has to be said though, there doesn't have to be visual indication for a cap to be bad. It can look good but measure bad (out of spec). Good luck with your repair!

[akuretz]

Re: Subwoofer Power Supply Problem

Thanks, since two people in this topic have the same subwoofer and already replaced the capacitors I'm hoping they can just post what they bought. I'm not able to edit my profile yet (new user) but I'm in Fort Collins, CO. The photo montage thread is cool, thanks for sharing the link to that!

[Wrog]

Re: Subwoofer Power Supply Problem

Thanks, since two people in this topic have the same subwoofer and already replaced the capacitors I'm hoping they can just post what they bought. I'm not able to edit my profile yet (new user) but I'm in Fort Collins, CO. The photo montage thread is cool, thanks for sharing the link to that!

USA is good enough for a location. Ordering from Digikey is probably your best bet. The listing I saw on page 1 was:

(2X) REC , SR , 47uF , 16V , 85C , 124mA , 5x11mm
(2X) REC , SR , 470uF , 16V , 85C , 440mA , 8x12mm
(2X) REC , SR , 1000uF , 25V , 85C , 925mA , 10x20mm

The problem is that there seems to be more caps that what was listed. Typically folks around here recommend that they all get replaced (except for the giant ones) so you don't have to fix it again in 6 months. I'd go with the following:

47uF, 16V -> Nichicon PW
470uF, 16V -> Panasonic FM (assuming you can squeeze a 10mm diameter in that space since the original is 8mm)
1000uF, 25V -> Panasonic FM (assuming you can squeeze a 12.5mm diameter in that space since hte original is 10mm)

Hopefully one of the guys who repaired theirs recently comes back and shares their info!

[Rusled]

Re: Subwoofer Power Supply Problem

My location is Tehachapi Calif, daughter who owns sub is in Bakersfield calif

[darkfinger]

Re: Subwoofer Power Supply Problem

Hi there,

Thanks to this forum, I just ordered some caps from Digikey for my humming Onix. They were all Nichicon PW caps:

2x 493-1832-ND CAP 1000UF 25V ELECT PW RADIAL
2x 493-1775-ND CAP 47UF 16V ELECT PW RADIAL
2x 493-1786-ND CAP 470UF 16V ELECT PW RADIAL

Provided I don't screw up this installation, this'll be $3 well spent

Hope this helps,
Dave

[lownote]

Re: Subwoofer Power Supply Problem

i have a ufw 10 made by onix av123, it makes no nois plugged in ,but when a signal is sent via rca cable ,it then makes some high pitched whining noise, maybe caps in the pre amp section? help!!!!!

[lownote]

Re: Subwoofer Power Supply Problem

this is the power supply board in my ufw10 says mfw v2.1? need 1x 22uf 160v,2x 470u 35v 1x 1000uf 35v, any suggestions on what to use?

[al walwala]

Re: Subwoofer Power Supply Problem

Hey all,
I owned a Onyx ULW-10 since 2005. I really love its performance. unfortunately it just gave up the ghost early this year. I read here that the filter cap in the power supply is prone to self destruction. I want to thank you all for the wonderful insight on this problem, however, my sub-woofer besides the hum it also makes a really bad clunking sound when there is very loud low frequencie in the signal. I would guess it's just the mounting for the woofer pulled out of the mount. I have not open the unit yet, but will be openning it soon. Finger crossed...

[al walwala]

Re: Subwoofer Power Supply Problem

I ordered from DigiKey the Panasonic replacement capacitors the same values as on the P/S board but 105C instead of the 85C caps that was on the board. Although in my case I don't think it was necessary, because one of the 1000 uf cap had a cold solder joint. I think if I re-soldered it, I probly could have more service out of the unit. Since I already replaced 3 other caps, I just went ahead and replaced them all and soldered them with professional solder joints The unit is now working superbly. good luck to you all. May the woofer be with you (for a long long time).

[al walwala]

Re: Subwoofer Power Supply Problem

Oh! I also replaced the 2, 2200uf 160V 85 C with 2200uf 160V 105C Panasonic caps as well.

[jski04]

Re: Subwoofer Power Supply Problem

This site is fantastic! My Onix sub has been out of commision for over a year because of the hum. I've just ordered the parts Wrog suggested above. Looking foward to rattling the walls again. I'm glad I'm not the only one to purchase this product from the now defunct AV123 site.

Anyone see the stories about the owner of the company and his problems?

[jski04]

Re: Subwoofer Power Supply Problem

Anybody who's repaired their sub near the Minneapolis area?

[runway]

Re: Subwoofer Power Supply Problem

Thanks to this thread I have my sub working again. I got the Nichicon replacements from Digi-Key and all's good. It's a little tricky getting the board out to work on. I was concerned about replacing the caps myself, as I had never done anything like that before. All you need is a hot gun, a little solder and common sense as to the polarity on the caps. Thanks again.

[fschris]

Re: Subwoofer Power Supply Problem

I am sorry I know this post is dated.. however does anyone have a blown AV123 transformer from a ulw/ufw 10 ( a toroidal type ) I have a pic of the one I am looking for.

fschris

[Longbow]

Re: Subwoofer Power Supply Problem

Since the amp uses a conventional power supply, any general purpose cap that fits the available space will work fine. Further fussing is unnecessary. Since the amp module is enclosed inside the cabinet with lots of insulation (which keeps the heat in), going to a higher temp rating would make sense (105 degree instead of the 85 degree shown).

[lti]

Re: Subwoofer Power Supply Problem

If this was a linear power supply, what are the big 2200uF 160V caps for?
This power supply circuit is confusing.