I got recently jamo subwoofer model is sub 300.the problem was no power.when i checked smps i found that two mosfet shorted at primery side.after i replaced power is ok now but when i am testing with audio signal i and geting distortion bass is ok but distortion at high freequency of music..i checked the speaker with other amplifier speaker is fine..so i suspect issue in pre amp stage or high freequency cut off stage..
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Re: Jamo sub 300 subwoofer distortion
Hi any one have schematic for this subwoofer -
Re: Jamo sub 300 subwoofer distortion
There might be some useful ideas here:
https://www.eevblog.com/forum/repair...-board-repair/
And on a personal note, i bought a dead Jamo Sub 200 for really cheap a few years ago, and the problem turned out to be that the volume and low-pass adjust pots had crapped out. That might be worth looking into, as well.Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - ShenanigansComment
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Re: Jamo sub 300 subwoofer distortion
[QUOTE=Khron;776365]There might be some useful ideas here:
https://www.eevblog.com/forum/repair...-board-repair/
And on a personal note, i bought a dead Jamo Sub 200 for really cheap a few years ago, and the problem turned out to be that the volume and low-pass adjust pots had crapped out. That might be worth looking into, as well.[/QUOTE
volume and lpf adjust pots are working well... what i understand that on high frequency content not attenuating properly, distortion from high frequency signal.. even i cannot hear any vocal male voices through sub.Comment
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Re: Jamo sub 300 subwoofer distortion
I have no idea if the line-level circuitry is the same between the 200 and the 300, but when i was working on mine, i "decoded" the whole board - see attachment.Attached FilesKhron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - ShenanigansComment
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Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - ShenanigansComment
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Re: Jamo sub 300 subwoofer distortion
It helps to read through the whole thread, especially since there were only a handful of 2-3-sentence posts...Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - ShenanigansComment
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I've got a subwoofer that I've had for nearly 20 years, it did come with a basic remote which I've lost. It's a generic make of subwoofer, I can't see a brand sticker on it. It comes with 2 speakers.
Question recently I've connected it up to my tv which has greatly improved the sound on my tv, however I'd like to be able to mute the subwoofer when ads come on or just mute it when the phone rings etc. I tried using a cheap all in one tv remote on the subwoofer and the volume button would only work to increase volume but not turn it down or mute it
Is there a way of... -
I’ve got a subwoofer that I’ve had for nearly 20 years, it did come with a basic remote which I’ve lost. It’s a generic make of subwoofer, I can’t see a brand sticker on it. It comes with 2 speakers.
Question recently I’ve connected it up to my tv which has greatly improved the sound on my tv, however I’d like to be able to mute the subwoofer when ads come on or just mute it when the phone rings etc. I tried using a cheap all in one tv remote on the subwoofer and the volume button would only work to increase volume but not turn it down or mute it
Is there... -
Good day ladies and gentleman!
I am currently trying to repair a Grundig Vision 9 37 9880 T USB LCD TV for a friend that has a weird audio problem. Basically everything works fine except for the heavily distorted sound when the Subwoofer module is connected and there is a buzzing sound coming from the PSU PCB.
This seems to be a rather rare TV so there is not much prior on topic help to be found however a service manual is available at the usual sources (Electro Tanya i.e.).
I think the PSU buzzing comes from one of the coils near the bridge rectifier but... -
I get a faint, low hum through my PC speakers, which connect to the subwoofer in a 2.1 speaker system. The hum drives me crazy and makes me stressed. When I turn off the subwoofer, everything is quiet and I start to relax, lol.
Here's an audio clip of the sound coming from my speakers:
https://vocaroo.com/16HaryHwTx78
I recorded with my phone's mic right next to the speaker, and the mic picked up a lot of speaker noise over top of the hum. But I don't hear that noise in the room, I just hear the lower-pitched hum that's buried beneath all the other... -
Hi. I have been watching videos on how a power adaptor works.
There is explanation of the rectifier bridge to the pulse width modulator, the mosfet for switching, and opto-couplers, but there is little to nothing about the AC stage of the transformer the powers the primary coil.
So, I see that the PWM needs DC to work, but I don't see anything about how the AC gets from the mains supply to the transformer stage.
A transformer only works on AC so where is that part of the circuit.
I only see Capacitors on the output. Should I assume that the secondary coil and...
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