It should. I bought one for $60 that hummed. Although I replaced all of the electrolytics on the amp bird (except the filter caps) fixed the problem. It’s such a big subwoofer though. Kinda ugly too (I don’t care, but my folks do) I’ve been using a PV1000. MUCH smaller and also very nice sounding.
I replaced the voltage regulators first, still humming. I moved on to C13, C18 capacitors, come to find out it was c13 causing the problem. I noticed a very slight bulge in the top,but only after close inspection.
I am super happy! I now have a great system for listening to music and movies.
Many thanks to VidTech for showing us the way. And to ouimetnick for your personal help with this project.
Now it's on to fixing my vintage sx-1250 receiver! Something tells me it's not going to be as easy as this project.
I am super happy! I now have a great system for listening to music and movies.
Many thanks to VidTech for showing us the way. And to ouimetnick for your personal help with this project.
Now it's on to fixing my vintage sx-1250 receiver! Something tells me it's not going to be as easy as this project.
Boston HPS10HO- CPS10 WI humming
Hello, has anyone had any luck repairing a Boston HPS10HO and CPS10 WI making a humming noise ? They look to be similar plate amplifiers. According to Boston Acoustics repairs there is no schematics available for these and they are unable to repair. I have 2 of the CPS10s and one HPS10 HO. The hum on the HPS10 HO started after being unplugged from power over night. One of the CPS10 was new had only been plugged in to test 5 yrs ago then stored in attic. Please let me know.
Thanks,
Kyle
Hello, has anyone had any luck repairing a Boston HPS10HO and CPS10 WI making a humming noise ? They look to be similar plate amplifiers. According to Boston Acoustics repairs there is no schematics available for these and they are unable to repair. I have 2 of the CPS10s and one HPS10 HO. The hum on the HPS10 HO started after being unplugged from power over night. One of the CPS10 was new had only been plugged in to test 5 yrs ago then stored in attic. Please let me know.
Thanks,
Kyle
Parts and perhaps and perhaps a service manual for my BA VR-2000 sub?
I know it's a bit of a long shot posting to a 10 year old thread but I can dream right and hope that fate will sow some kindness (along with the rest of you)
I have a sub with the a thread problem. Issue started a while back but would clear for a while then eventually come back. It's gotten to the point of being much more pronounced and dosen't seem to be subsiding so likely I have her the cap problem but of course would have a better idea after tearing down the sub and inspecting the board. I bought the sub about 20 years ago when it was new (only owner, from factory) so I have plenty of history with it.
I searched YouTube & Goggle bout couldn't find either a service manual or teardown video for a starting point. I'm hoping that someone here might have some doc that might help. Ultimately I am sure I can figure out starting with the 8 screws that surround the input panel then move out if this dosen't remove the panel and the board is not on the backside. I'll try removing it with speaker inverted so if anything comes lose it doesn't go INTO the speaker cavity.
Second assume I remove the power supply board I need to source the 2 sets (4 in total) Caps and 2 regulators. Since Im going through all this effort see no reason other then the time required NOT to replace all 4 mentioned component groups. I'm trying to find replacements and it's been since HS since I did REAL electronics work (building a board from scratch/etching traces etc). Was back in the days where we did this with physical tape, an exacto knife and acid bath. Yeah ol' school photo etch. Sure plenty of repairs, solder and etc, but not part sourcing or substitution. ANYWAYS I really could use help on selecting appropriate replacements for the parts as I am not familiar with things like ripple current etc (though learned a fair amount from net). I would like to find best audio quality components as cost on these seem to be pretty minimal in general. If any one has done this and can shoot me URLs to the parts you ordered OR even more fully qualified values (dimensions, ripple, thermal values, etc) I would be forever in your debt. Seems that Polypropylene caps (Film or Foil) seem best IF they will fit the physical space (which I don't know)
Sources:
Thanks for ANY help you can offer, and more than willing to summarize entire process (might even push a YouTube video my first ever), on the chance it helps someone else!
Trying to save a great friend here from an "untimely" demise. No reason for this to end up in a landfill.
--Tom
I know it's a bit of a long shot posting to a 10 year old thread but I can dream right and hope that fate will sow some kindness (along with the rest of you)
I have a sub with the a thread problem. Issue started a while back but would clear for a while then eventually come back. It's gotten to the point of being much more pronounced and dosen't seem to be subsiding so likely I have her the cap problem but of course would have a better idea after tearing down the sub and inspecting the board. I bought the sub about 20 years ago when it was new (only owner, from factory) so I have plenty of history with it.
I searched YouTube & Goggle bout couldn't find either a service manual or teardown video for a starting point. I'm hoping that someone here might have some doc that might help. Ultimately I am sure I can figure out starting with the 8 screws that surround the input panel then move out if this dosen't remove the panel and the board is not on the backside. I'll try removing it with speaker inverted so if anything comes lose it doesn't go INTO the speaker cavity.
Second assume I remove the power supply board I need to source the 2 sets (4 in total) Caps and 2 regulators. Since Im going through all this effort see no reason other then the time required NOT to replace all 4 mentioned component groups. I'm trying to find replacements and it's been since HS since I did REAL electronics work (building a board from scratch/etching traces etc). Was back in the days where we did this with physical tape, an exacto knife and acid bath. Yeah ol' school photo etch. Sure plenty of repairs, solder and etc, but not part sourcing or substitution. ANYWAYS I really could use help on selecting appropriate replacements for the parts as I am not familiar with things like ripple current etc (though learned a fair amount from net). I would like to find best audio quality components as cost on these seem to be pretty minimal in general. If any one has done this and can shoot me URLs to the parts you ordered OR even more fully qualified values (dimensions, ripple, thermal values, etc) I would be forever in your debt. Seems that Polypropylene caps (Film or Foil) seem best IF they will fit the physical space (which I don't know)
Code:
C17, C19 - 100 ufd @ 16 vdc radial electrolytic capacitor.
C13, C18 - 470ufd to 1000ufd@ 25 volt radial electrolytic capacitor
U2 - LM7912 3 pin negative 12 volt regulator
U3 - LM7812 3 pin positive 12 volt regulatorSources:
Code:
[URL="https://www.mouser.com/Passive-Components/Capacitors/Aluminum-Electrolytic-Capacitors/Aluminum-Electrolytic-Capacitors-Radial-Leaded/_/N-75hqw?P=1z0wrkmZ1yztuatZ1yx4aw3"]Mouser Caps- C17, C19 - 100 ufd @ 16 vdc radial electrolytic capacitor[/URL]
DigiKeyThanks for ANY help you can offer, and more than willing to summarize entire process (might even push a YouTube video my first ever), on the chance it helps someone else!
Trying to save a great friend here from an "untimely" demise. No reason for this to end up in a landfill.
--Tom
Finally fixed my 120hz hum. I had already tried:
-replacing bulk capacitors for the +/-80v rails
-replacing +/-12vdc voltage regulators
-replacing +/-12vdc regulator capacitors (4 total)
-twisting primary and secondary windings on transformer into twisted pairs
-adding tiny tantalum capacitors to the +/-12vdc regulators
The things above helped revive the amplifier and get it working again, however I still have a 120Hz hum that was clearly audible from my couch.
The solution was changing the 12vdc supply for the speaker protection relay from the input side of the +12vdc regulator to the output side. See pictures below.
I believe the factory originally had powered the speaker protection relay from the 80vdc positive rail and decided that was a bad idea. You can see where the trace was sanded off the board on the left side of the picture. The factory appears to have added a black wire to power that relay from the +12vdc but they soldered it to the input side of the +12vdc regulator which has a strong 120Hz ripple from the rectifier. I think the ripple went through the relay coil and into the (everything) ground and resulted in noise (everywhere).
When I moved that wire to the output side of the +12vdc regulator, the 120Hz noise stopped and the amplifier is dead silent now. Hooray! I hope the pictures below help.
Also, I made a schematic of the amplifier board if anyone wants it. It's a rough draft and I likely made a mistake in there somewhere, but it should be useful.
--> Find the schematic over here <--
-replacing bulk capacitors for the +/-80v rails
-replacing +/-12vdc voltage regulators
-replacing +/-12vdc regulator capacitors (4 total)
-twisting primary and secondary windings on transformer into twisted pairs
-adding tiny tantalum capacitors to the +/-12vdc regulators
The things above helped revive the amplifier and get it working again, however I still have a 120Hz hum that was clearly audible from my couch.
The solution was changing the 12vdc supply for the speaker protection relay from the input side of the +12vdc regulator to the output side. See pictures below.
I believe the factory originally had powered the speaker protection relay from the 80vdc positive rail and decided that was a bad idea. You can see where the trace was sanded off the board on the left side of the picture. The factory appears to have added a black wire to power that relay from the +12vdc but they soldered it to the input side of the +12vdc regulator which has a strong 120Hz ripple from the rectifier. I think the ripple went through the relay coil and into the (everything) ground and resulted in noise (everywhere).
When I moved that wire to the output side of the +12vdc regulator, the 120Hz noise stopped and the amplifier is dead silent now. Hooray! I hope the pictures below help.
Also, I made a schematic of the amplifier board if anyone wants it. It's a rough draft and I likely made a mistake in there somewhere, but it should be useful.
--> Find the schematic over here <--
Attachments
Last edited:
Parts list for anyone wondering:
Digikey:
Q11 & Q13
part: 2SC5200-OQ-ND
Q7 @ Q9
part: 2SA1943-OQ-ND
U2
part: LM7912CTFS-ND
U3
part: LM7812CTFS-ND
U2 & U3 bypass caps (not in schematic)
part: 478-1831-ND
CAP TANT 0.1UF 35V 10% RADIAL
C13 & C18
part: 493-1827-ND
CAP ALUM 470UF 20% 25V RADIAL
C17 & C19
part: UVY1E101MDD-ND
CAP ALUM 100UF 20% 25V RADIAL
C2 & C3 (bulk caps for rails)
part: 338-2109-ND DESC: CAP ALUM 12000UF 20% 80V SNAP
(note! these are a poor fit because they are too large diameter)
(you could use four smaller ones instead of two oversize ones like these)
Digikey:
Q11 & Q13
part: 2SC5200-OQ-ND
Q7 @ Q9
part: 2SA1943-OQ-ND
U2
part: LM7912CTFS-ND
U3
part: LM7812CTFS-ND
U2 & U3 bypass caps (not in schematic)
part: 478-1831-ND
CAP TANT 0.1UF 35V 10% RADIAL
C13 & C18
part: 493-1827-ND
CAP ALUM 470UF 20% 25V RADIAL
C17 & C19
part: UVY1E101MDD-ND
CAP ALUM 100UF 20% 25V RADIAL
C2 & C3 (bulk caps for rails)
part: 338-2109-ND DESC: CAP ALUM 12000UF 20% 80V SNAP
(note! these are a poor fit because they are too large diameter)
(you could use four smaller ones instead of two oversize ones like these)