Infinity PS-12 Powered Subwoofer Fired Amplifier

[CptanPanic]

Just wanted to say that my PS-10 is now exhibiting the clicking after running for a few hours. Any suggestions? Should I just put the spacer to keep things cooler, or should I go ahead and re-cap?

[time4this]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

PS-10 here with the C71, C72 issues. Thanks to everyone who has contributed to this valuable repository of knowledge! Amazing.

Has anyone figured out why C71 flames out? What causes this failure mode? I've read through the pages here and don't seem to find anyone elaborating on the causes of this condition. I've got parts ordered to replace, but I'd like to know it is not going to happen again. I'm also going to put a couple air holes to allow some convection (hopefully) to occur. Fingers crossed.

[Asimo5000]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

you can check that sub with any of the channels from the receiver?? I assume your hooking this sub amp up to something? Sub output of receiver? Use any of the 7 speaker outputs on that to test woofer.

True ! Forgot that can work lol

Let me check its impedances on my receiver

[Jodeanss]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Thank you for the reply, I'll start by verifying the driver since it's a simpler step before going for capacitors

To find adequate replacement Caps, do I just need to match the voltage and uF rating? I didn't see other specs listed on the existing caps

you can check that sub with any of the channels from the receiver?? I assume your hooking this sub amp up to something? Sub output of receiver? Use any of the 7 speaker outputs on that to test woofer.

[momaka]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Thank you for the reply, I’ll start by verifying the driver since it’s a simpler step before going for capacitors

Sounds like a reasonable place to start.

To find adequate replacement Caps, do I just need to match the voltage and uF rating? I didn’t see other specs listed on the existing caps

The voltage and capacitance (uF rating) are the main parameters, but there are a few more that you may need to match (or exceed in superiority.)

For starters, the temperature rating: if the original caps are rated only for 85C, then they are general purpose (GP) caps, and indeed matching only the voltage and capacitance (uF) rating is usually adequate. If the caps are rated for 105C, they may or may not be low-ESR type (actually, low impedance.) For low ESR type, you have to check two additional parameters of the original caps: their ESR (impedance) and ripple current (RC). This you can get from the datasheet of the original caps by looking up their brand and series. But beware that this could turn out into a wild goose chase, as some obscure and/or cheap cap brands may not have published datasheets or incomplete data sheets. For the ones you can find datasheets, though, note the impedance and ripple current for each cap type you have. Then make sure the replacement caps have the same or lower impedance/ESR and same or higher ripple current.

Is it critical to match the ESR and RC rating?
- No, most of the time.
This being a subwoofer, the caps are probably regular GP type or "entry-level" low ESR at best... so should be pretty easy to find replacements.

With all of that said, here's the easier way to go about finding replacements: just use entry-level low-ESR caps for every cap, and it should be OK.

Since you're in the North America, my suggestion is to order online from reputable websites, such as Digikey or Mouser, and use only Japanese brands (Rubycon, Nichicon, Panasonic, and United Chemicon / Nippon Chemicon), since these are the most reliable electrolytic cap brands.

Each cap brand has a series. Different series have different ESR and RC ratings. Here are some series from each Japanese brand mentioned, which should be OK for this type of use (amplifier / audio):

Rubycon YXJ, YXH, YXF, ZLJ, ZLQ, ZLS, ZL
Nichicon PS, PM, PW, HE, HD, HW, HV
United Chemicon LXV, LXY, LXZ, KYA, KYB, KY, KZE
Panasonic FC, FM, FR, FS

These may also work OK for general purpose 85C or 105C caps:
Rubycon: PX
Nichicon: VR, VZ, VY
UCC: KMG
Panasonic: EB, NHG, M-series

And for audio path circuits only (i.e. not part of the power supply filtering):
Nichicon: FW, FG, KW, KT, KA
^ Note that these audio caps may be more expensive. While they are recommended (by cap manufacturers) for use in audio path circuits, they aren't necessary. Any GP or entry-level low ESR series will do OK in audio path circuits too. According to the cap manufacturers, though, these audio caps may be better for the audio quality... but this being a subwoofer, it shouldn't really matter, since you're only dealing with LF (low frequencies.)

[Asimo5000]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Thank you for the reply, I’ll start by verifying the driver since it’s a simpler step before going for capacitors

To find adequate replacement Caps, do I just need to match the voltage and uF rating? I didn’t see other specs listed on the existing caps

[momaka]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Should I just start replacing caps anyway?
I get nothing out of it at all, have never seen the woofer move.

Yes, start by replacing all of the small electrolytic capacitors, and with good brands if possible. At this age, the old ones are very likely on their way out, given the brand they are.

Great wealth of information on this thread. I was trying to troubleshoot with DMM and I couldn't locate some of the components, I would like to point out some are on the back of the PCB, especially the smallest kinds.

In my case I have owned this subwoofer since about 2008 (PS12). I didn't have issues until after 2014 I would get a chirp on startup. This progressed to clickiy standby especially in movies where the bass wasn't requested. Fast forward to late 2022 the sub no longer would do anything and would only click.

Today I spent the day troubleshooting the circuitry, suspecting the big caps were bad as many others did, however voltages all appear to be in check. The only thing I can say with certainty is there is a residue around AC1/AC2/AC3 leads that is sticky, also the board gives off some heat in similar area. Voltages seemed OK, resistance OK, voltage on downstream circuit +15V I measured +14V. I could see a changing voltage (AC) when measuring the output speaker leads.

Hi Asimo and welcome to BCN.

Given all the people that have fixed these subwoofers by replacing the small electrolytic capacitors, I would say do this as well for your first troubleshooting step. Just because voltages appear OK on a multimeter does not mean the caps are doing their job. Ripple and noise will not show on a multimeter, nor would the internal leakage of a cap in a signal path (unless you remove each cap and put on a leakage test circuit to verify.) These are usually what tends to kill hot-running subwoofer amp boards. So plan on replacing every small capacitor and some of the medium ones too. Only the big ones are less likely to fail... though not always.

In my case, I suspect it actually is the driver. The driver doesn't move or make much noise when using 9V battery. However it is not open loop, and impedance is fine at ~4 ohm. I am not sure how to verify either amp or driver.

The driver is easy and you don't need an amplifier for that.

Just grab a 20-35 Watt 120V (or 230V if you have 230V mains) incandescent/halogen light bulb, or 15-35 Watt corded soldering iron, or even a 10-15 Watt hot glue gun would work. Disconnect woofer driver from amplifier board completely (both leads). Then, using jumper leads, connect one terminal on the woofer to Neutral and the other to one side of the incandescent/halogen bulb mentioned above (or soldering iron or hot glue gun.) Now *carefully* wire the other side/lead/terminal of the incandescent/halogen bulb to 120V AC live (BEWARE that you're working with AC Live here, which can be DANGEROUS and lead to electrocution, so that's what I mean by be careful.) Essentially, you're putting the light bulb in series with the speaker to limit current / power going to the speaker driver so that it doesn't burn out. Once wired up, the circuit will look like this, where "unit to test" corresponds to your speaker driver. At 10-35 Watts (depending on light bulb or soldering iron power rating used), beware that you would get quite a bit of sound and movement from the speaker. In fact, it's a good idea to keep it in the cabinet/enclosure for this test (and screwed in) to prevent bottoming out in free air. Definitely DO NOT use a bulb or iron rated higher than 40 Watts. If this test doesn't make some noise, your driver may be faulty.

Alternative (and much SAFER low-voltage) test for the woofer driver:
using a pair of sacrificial / cheap ear buds or other headphones, remove the headphone drivers / buds and use the cord with the 3.5 mm jack to connect the woofer driver directly to your phone or PC (or other device with sound output.) 3.5 mm audio jacks typically have very limited power, so you won't get much sound from the woofer, but you should still be able to hear whatever your playing (alas very mid-range-y and probably muffled-sounding.)

My personal suspicion is your speaker driver is OK. The amp, I can't say. But with very old electrolytic caps on the board, I'd say the amp is probably OK too, and it's just the old caps causing the issue (hence the suggestion to start with the recap first.)

[Asimo5000]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Great wealth of information on this thread. I was trying to troubleshoot with DMM and I couldn't locate some of the components, I would like to point out some are on the back of the PCB, especially the smallest kinds.

In my case I have owned this subwoofer since about 2008 (PS12). I didn't have issues until after 2014 I would get a chirp on startup. This progressed to clickiy standby especially in movies where the bass wasn't requested. Fast forward to late 2022 the sub no longer would do anything and would only click.

Today I spent the day troubleshooting the circuitry, suspecting the big caps were bad as many others did, however voltages all appear to be in check. The only thing I can say with certainty is there is a residue around AC1/AC2/AC3 leads that is sticky, also the board gives off some heat in similar area. Voltages seemed OK, resistance OK, voltage on downstream circuit +15V I measured +14V. I could see a changing voltage (AC) when measuring the output speaker leads.

In my case, I suspect it actually is the driver. The driver doesn't move or make much noise when using 9V battery. However it is not open loop, and impedance is fine at ~4 ohm. I am not sure how to verify either amp or driver.

I will see if I have leftover car speakers that I can run off the amp for quick test. Other than that I am not sure what else to do, I no longer have car amps that I can use to test the driver

Any thoughts?

[Jodeanss]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

I've read the entire thread now. I thought my amp had obvious signs of what was wrong but all I found was a little browning by the resistors..... and no one mentioned anything like what is happening with mine ..... got this wierd zap sound happening.

https://youtube.com/shorts/_duiud-yCZk?feature=share

https://youtube.com/shorts/I8oVNq_59eQ?feature=share

Should I just start replacing caps anyway?
I get nothing out of it at all, have never seen the woofer move.

[momaka]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

I'll start with my question and then give background....

Q1: C65 is listed in the repair manual as 470uF but the installed part appears to be 47uF. Unfortunately, I ordered replacement parts based on the manual. Also, on the board the outlined footprint of the cap is much closer to the larger 470uF chassis. Admittedly, C37 is also a smaller chassis cap with a larger footprint. I'll likely test and reinstall the 47uF cap at C65 and see if this amp will function again.

https://www.manualslib.com/manual/10...ected=1#manual

Does anyone have any input as to which value is actually correct?

I found some information in the following two posts:
https://www.badcaps.net/forum/showpo...&postcount=130
https://www.badcaps.net/forum/showpo...&postcount=133

To highlight the important part, this is what jiari put down:

I see the note on AresROC's blog that changing C65 from 470uF to 47uF fixes the chirp. Honestly, I can't tell if it's ok to swap out. The change looks ok to me (IR2111 seems to be used very closely in line with the application notes which only called out the bypass cap), but I don't know amplifier design. AresROC mentioned in post #94 that it was a design change on his revision D board. I'll give it a try if I need something from Mouser. I'm not that bothered by it.

Also, I looked at the IR2111 datasheet myself, and while it doesn't list a sample / application circuit, it does show two test circuits, both of which have 10 uF caps for what would correspond to C65. So I think anything down to that value may be OK to use. In your case, I suggest going with whatever values was installed there originally (looks like 47 uF). But if you don't want to buy replacement caps just for that, then you can try the 470 uF caps too. As per the other posts, it seems the older revisions of this sub used 470 uF caps. So the change should not have any adverse effects, other than perhaps a high-pitched chirp during power On.

When in doubt, you can always use the incandescent lightbulb "trick" in series with the AC live to limit power/current, in case something does go wrong.
https://www.badcaps.net/forum/attach...chmentid=10462

I'm at the point now to where I need to get my dining room table turned repair station cleaned off before my wife gets home so I'm going to reinstall the C65 47uF cap and hope that this turns out to be the correct recommendation.

Lol. At least you only have a sub on there. I have an entire 55" TV taken apart, and it's been sitting there for a week. But then I don't have a wife to complain to me so... all is fine?

C65, I thought this cap was SAMXON branded but after pulling it I see it appears to be "Su'scon"

Su'scon, SAMXON... whatever. Neither is that much better than the other.
Pretty much the only worthwhile cap companies today, at least for reliable small-can electrolytics, are Panasonic, Rubycon, Nichicon, and United Chemicon, which are all Japanese brands too. Sanyo/Suncon are too, but you'd be hard-pressed to find these for sale anywhere. The ones on eBay and Amazon are typically counterfeits.

C72 and C73: these NP caps appeared fine visually and I don't suspect they were part of the problem but there are posts in this thread that show these can cause problems. Figured it would be cheap and wise to replace them while I had everything apart. Digi-Key only had polarized caps of the correct specs so I ordered two of each and installed them in opposing polarity.

Should be OK with that.

Thanks to everyone who has contribute info here over the years, I wouldn't have attempted this repair without what I found here.

Let us know how the repair goes/completes.

[Flying Trunk Monkey]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

This thread has been in circulation for over 10 years now, why stop?

I actually joined this board after googling how to fix my PS-12 amp so I could see this pics referenced.

I'll start with my question and then give background....

Q1: C65 is listed in the repair manual as 470uF but the installed part appears to be 47uF. Unfortunately, I ordered replacement parts based on the manual. Also, on the board the outlined footprint of the cap is much closer to the larger 470uF chassis. Admittedly, C37 is also a smaller chassis cap with a larger footprint. I'll likely test and reinstall the 47uF cap at C65 and see if this amp will function again.

https://www.manualslib.com/manual/10...ected=1#manual

Does anyone have any input as to which value is actually correct?

I'm at the point now to where I need to get my dining room table turned repair station cleaned off before my wife gets home so I'm going to reinstall the C65 47uF cap and hope that this turns out to be the correct recommendation.

Background:
I decided to replace the following components based on info found throughout the thread as I had the power relay rapidly switching/buzzing condition (with no sound output) that seems to be a common issue.

C2,C4,C9: commonly suspected issue because the SAMXON branded caps throughout the amp seem to be of questionable quality, also the caps in this location are in the vicinity of the 4 resistors that appear to run VERY warm.

C6, C9: powers supply caps, appeared good visually but they are SAMXON branded and aged

C12, C78: commonly suspected issue because the SAMXON branded caps throughout the amp seem to be of questionable quality, and also because C12 is in the vicinity of the 4 resistors that appear to run VERY warm.

C65, I thought this cap was SAMXON branded but after pulling it I see it appears to be "Su'scon"

C72 and C73: these NP caps appeared fine visually and I don't suspect they were part of the problem but there are posts in this thread that show these can cause problems. Figured it would be cheap and wise to replace them while I had everything apart. Digi-Key only had polarized caps of the correct specs so I ordered two of each and installed them in opposing polarity.

Thanks to everyone who has contribute info here over the years, I wouldn't have attempted this repair without what I found here.

[backcountrymountains]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

So, I now have a broken PS-10 with the same vaporized C71 and a slightly bulging C6.

Can anyone post a definitive list of parts to replace? @mhren?

Thanks

My Infinity Entra Two is working good as new.

Not sure if this is visible to others but here is the bill of materials I used at Digikey for the caps.
https://www.digikey.com/BOM/Create/C...?bomId=8604745

My board was a first revision so I used the original caps except for C37 which I upped to a 270uF since my sub normally didn't stay (green) on for the full 10 minutes before going back to standby after no input (now it does)

Add to this the small ceramic cap in my prior post that was unique to my failure along with the two crossover caps posted by jiari in post #119. I also put a bit more silicon next to the new NP caps so it looks as good as new

https://www.parts-express.com/6.8uF-...acitor-027-336
https://www.parts-express.com/4.7uF-...acitor-027-332

Thanks to everyone that's posted in this thread before .. lots of good info here to help complete this worthwhile repair.

[R_J]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Your Digikey link can't work unless you want to provide your login and password, which I would suggest you do not.

[mhren]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

My Infinity Entra Two is working good as new.

Not sure if this is visible to others but here is the bill of materials I used at Digikey for the caps.
https://www.digikey.com/BOM/Create/C...?bomId=8604745

My board was a first revision so I used the original caps except for C37 which I upped to a 270uF since my sub normally didn't stay (green) on for the full 10 minutes before going back to standby after no input (now it does)

Add to this the small ceramic cap in my prior post that was unique to my failure along with the two crossover caps posted by jiari in post #119. I also put a bit more silicon next to the new NP caps so it looks as good as new

https://www.parts-express.com/6.8uF-...acitor-027-336
https://www.parts-express.com/4.7uF-...acitor-027-332

Thanks to everyone that's posted in this thread before .. lots of good info here to help complete this worthwhile repair.

[mhren]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Hi everyone,

I just acquired a PS-12 and the cap is blown(of course.), but it also burned the board...

Is this fixable? I have not seen another one that is burned this much...

https://imgur.com/gallery/mfwxtNk?fb...YF9kI2iZClRpwU

I know this post was from quite a while ago but I'm wondering how this worked out for you? Looking at that last picture it seems C71 exploded (and it took out D34 with it)!!

Here's a picture of mine and you can see the same exact part failure (this is on the bottom of the board just in parallel with the crossover cap C73 that was bulging) BUT mine was not nearly as bad.

So I have replaced all the electrolytic caps and the two crossover bipolar caps and have just ordered a replacement for C71....

Unfortunately the specs for C71 is not listed in the manual on the parts page but I see on the schematic that it is a 0.1uF probably 100V. I ordered this but does anyone have an idea of what it really should be?
https://www.digikey.com/en/products/...K1RACTU/754779

Once I replace C71 I'll post how the repair went....

[sachs]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Nice Job. I would recommend putting standoffs between the box and the plastic. Otherwise, the fan will be rather ineffectual in pushing/pulling air into a closed box. I ended up removing my fan as it made too much air noise.

I opened a hole in the plastic, the fan draws hot air perfectly from the amplifier box

[jiari]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Finally after leaving the laziness aside I replaced all the caps practically and 4 more resistors and redid solders in addition to putting a fan to keep it warm, the result is that the subwoofer has never been so good, perfect.

Nice Job. I would recommend putting standoffs between the box and the plastic. Otherwise, the fan will be rather ineffectual in pushing/pulling air into a closed box. I ended up removing my fan as it made too much air noise.

[sachs]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

Finally after leaving the laziness aside I replaced all the caps practically and 4 more resistors and redid solders in addition to putting a fan to keep it warm, the result is that the subwoofer has never been so good, perfect.

[momaka]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

I am not familiar with the "dim bulb tester" that Electricboyo mentioned above. Is that an incandescent bulb in series with the 120 volt input to act as a fuse?

Exactly!
https://www.badcaps.net/forum/showpo...4&postcount=70
.
.
Note, however, that it won't actually act as a fuse; it will behave more like a current limiter. How much current goes through depends on the load you put on the power supply. Generally, you won't be able to run most power supplies with any significant load with the dim bulb tester (due to increasing voltage drop across bulb with increasing load.) In most cases, the dim bulb tester is just enough to allow the power supply to turn on and show you that nothing is shorted on the primary (i.e. bulb will go bright/lit otherwise.) But that is still very useful.

In the case of amplifier PSUs, though, I've found that typically you can run the amp at a very low to medium volume to test the operation. To allow for a bigger load, you can use two or three series bulbs all in parallel or a single 100-300W bulb.

[andy1]

Re: Infinity PS-12 Powered Subwoofer Fired Amplifier

That is correct. You can Google and there is a ton of info on this. Make sure you are careful to take precautions so that you do not get electrocuted as this involves 110VAC household mains supply. If you are not sure, get it checked out by a qualified person.