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....
jiari
Member
Last Activity: 03-03-2021, 06:46 AM
Joined: 04-15-2018
Location: Andover
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Thanks Bud. That's helpful. I wouldn't have guessed about the bypass caps and passing low frequency....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
You're right. I'm going crazy. Too much work plus 9 month old. Thanks for verifying....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Aw crap. I just realized that I didn't vet TIP41C vs TIP31C (original) like I vetted the MOSFETs. The gain on TIP41C is lower than TIP31C and it is used to set the VCC of IR2111. That drives the downstream circuitry that actually powers the speaker. I would hazard a guess that is the source of the lower output.
I'm working on fixing a different amp. When I buy parts, I'll replace TIP41C with TIP31C. I'll let you know how it goes....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Honestly, it's probably not worth the time to investigate. Glad everything worked out for you (and me)....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
You do realize that the PS410's auto on/off circuit turns off after ~10 minutes of no signal. Dialogue should be going through your centers and I doubt your sub gets any signal during that time. The behavior you are describing sounds normal.
As Budm noted, you could change a capacitor so that the sub stays on longer after receiving a signal.
[url]https://www.badcaps.net/forum/showpost.php?p=828214&postcount=140[/url]Re: Infinity PS-12 Powered Subwoofer...mplifier<br />...Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
I'm an idiot. I just checked my speaker settings and my subwoofer was set 10 dB lower than my fronts. I set them to be equal. I also realized I was sitting directly across from the side of the sub and the sub was pointed toward 20 ft or so of open air. And since this is front firing, most of pressure wave had no place to reflect off of (though some hit the opposite wall about 4 feet away). I stood in front of the sub for a bit and the pressure wave on my ears was oppressive. My ears are still ringing 2 hours later. I was also...Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Sorry, I quoted the wrong caps to test +/- 15V. It's C4 and C9....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
YAY! Budm is here.
Do you have any idea why the volume would be lower than original considering we changed a few components (that we believe are equivalent) and used metal film caps (just for the bypass caps)?...Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
For the standby issue, can you confirm you changed the following caps?
C2, C4, C6, C8, C9, C35, C37, C78
Can you also verify the +15V and -15V rails? You can turn on the amp without the speaker plugged in and just probe the + and negative of C6 and C8.
You can also just completely bypass the auto sense circuit if you want (though not preferred). We should see if we find any other problems first.
I can post a picture of how to do it if you want to go that route. It seems that the signal...Last edited by jiari; 05-24-2018, 12:19 PM.Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Please let me know if the c65 swap fixes the chirp. I'll probably do it.
As for the MOSFETs, I poured over the data sheets and am sure IRF640NPBF (made by Infineon) is a direct replacement for IRF640N (made by Infineon). You can pull up their data sheets and check yourself. What this means is that outside of the old IRF640Ns being damaged or slowly degrading, the new MOSFETs should not have had an effect on the output.
My understanding is that actual capacitors have a model with resistors in series (ESR)...Last edited by jiari; 05-24-2018, 04:06 AM.Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
I looked at the PS210 schematic which has the same basic layout as the PS12, particularly around IR2111. I'm sure the swap of 470uF (C65) to 47uF will be fine.Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
You have a pretty good point. I guess I would say a chirp is shorter than 0.5 second. A squeal is at least a second. I listened to the chirp coming from my subwoofer and it indeed could be classified either way depending on the listener and criteria used. It starts as a chirp and ends in an almost squeal (by my varied definition). I think we both now have functioning subs, which is great....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
That's funny. I also forgot to put the thermistor back first. I'm surprised you had such trouble with the screws in the heatsink.
To be honest, I was pretty ready for a bright spark and smoke when I first plugged the AMP in (I tested it a bit first before plugging into the speaker). Glad it seems to be working on your end.
Do you have a squeal or a chirp? My research says the chirp is normal, but not the squeal. The squeal seems to be related to the crossover caps (C72 and C73) [note...Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
It's alive.
1st try (still dead): I started by replacing everything except C72 and C73 because, why not. Same problem (no output even though relay clicks and I can verify the relay is working). I verified the rails and they looked about the same (I think one leg was low by a volt). One of the 15V diodes is probably going.
2nd try (worked): replaced C72 and C73. Output seems to work fine. I got this broken off Craigslist for $35, spent another $30 in parts. I don't know what it sounded like before....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Yep, it's always finding the time that's the problem. I'm still looking for mine.
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
Huh. My service manual (Rev 1 10/2004) doesn't have a reference to C17, C18. And my board has both of those spots blank....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
If you want to spend the money, here are the proper parts from parts-express:
[url]https://www.parts-express.com/68uf-100v-electrolytic-non-polarized-crossover-capacitor--027-336[/url]
[url]https://www.parts-express.com/47uf-100v-electrolytic-non-polarized-crossover-capacitor--027-332[/url]Re: Infinity PS-12 Powered Subwoofer...-027-336[/url]...Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
I ordered 2 film capacitors to replace the non-polarized. You'll notice I ordered a 10% film vs the 5% film you linked. A quick web search and it looks like the original part was 10%. I doubt it makes a difference. I'm pretty sure I just decided to save the 28 cents. It was cheaper to go film than to order NPE's off another site due to shipping costs.
I didn't notice any 200uF NPE capacitors in the BOM. Maybe you are referring to the polarized 220uF or 22uF?
I would change like for like whenever possible....Leave a comment:
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Re: Infinity PS-12 Powered Subwoofer Fired Amplifier
For the price, I think you're only spending another $10 or so for the Transistors + MOSFETs + extra Caps. Might as well lump them in. For me, that was the cost of shipping, so cheap insurance if I have to buy again.
I'd be cautious of putting a 110AC to 12VDC converter in there. I believe you're looking at getting one of the small switching power supplies. They can couple in noise depending on placement and the box is pretty small. Probably more of a concern is if you have to run the 110AC 60Hz around...Leave a comment:
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