Hi, recently my sony str av320 receivers' speakers were not outputting anything, and protect mode was turned on, so I checked the mainboard and one current detection transistor in the protection section was faulty. Do I replaced it and the protect mode was gone, but still no sound from the speakers. So it looks like the power amplifier chip which it uses ie STK 4192II was no more working.
When I checked locally there are no original ones available now, and all of them in the market were low-quality Chinese clones.
I was looking for a replacement power amp that has a low THD and good performance, can you guys please help me find one?
When I checked locally there are no original ones available now, and all of them in the market were low-quality Chinese clones.
I was looking for a replacement power amp that has a low THD and good performance, can you guys please help me find one?
I'm in Australia and usually buy my STKs for repairs from Wagner Electronics. I've never had a problem with their STKs being counterfeit, although I have not used one of their STK4192-MkIIs, which they list here: https://www.wagneronline.com.au/stk...ctronic-components/stk4192-2-25200/959497/pd/
It looks like a different package from the image shown, also the shipping costs will be huge right, I'm from india.
I was looking for some class ab options like 2sc5200.
I was looking for some class ab options like 2sc5200.
Hi . How much volts is power supply for stk? Those tda are limited in voltage , discrete designs are more flexible.
STK 4192II is specified as 50+50W, Max. +/- 52.5 V, for 8 Ohms: +/- 35.0V, and for 4 Ohms : +/- 31.0 V
Sony would have been using +/- 27 V or so... so 1875 / 3875 / 3886 can be used, or Mosfet kits.
7294 and 7293 also can be used.
Where are you in India?
Sony would have been using +/- 27 V or so... so 1875 / 3875 / 3886 can be used, or Mosfet kits.
7294 and 7293 also can be used.
Where are you in India?
Please measure and post actual rail voltages.
I think you realize you can´t just fit a 7294 there (just checking) but you are lucky your STK is mounted on its own board, so you can fully dispose of it and bolt a new amp board to existing heatsink.
EDIT: so 7294 it will be.
+/-36 is too hot for reliable 3886, plus lately they are all fakes/clones, so .....
I think you realize you can´t just fit a 7294 there (just checking) but you are lucky your STK is mounted on its own board, so you can fully dispose of it and bolt a new amp board to existing heatsink.
EDIT: so 7294 it will be.
+/-36 is too hot for reliable 3886, plus lately they are all fakes/clones, so .....
Im from kerala. Calicut.
I did a quick research and hope my stks are not down but something else went wrong. The basic diagnostic of the chip went well. Lemme check the otputs directly from the power amplifier module.
But this is single channel right?Please measure and post actual rail voltages.
I think you realize you can´t just fit a 7294 there (just checking) but you are lucky your STK is mounted on its own board, so you can fully dispose of it and bolt a new amp board to existing heatsink.
EDIT: so 7294 it will be.
+/-36 is too hot for reliable 3886, plus lately they are all fakes/clones, so .....
Sorry, yes, you´ll need two, side by side.
Hope they fit in available space.
Or search for an acceptable width stereo board.
When replacing existing boards, problem is more "space" or "mechanical" or "mounting" than actual "electrical".
"50W into 8 ohm amps" will by definition take about same rail voltages; like Enzo often says: "the amplifier is just that thingie between the power supply and the speaker"
Hope they fit in available space.
Or search for an acceptable width stereo board.
When replacing existing boards, problem is more "space" or "mechanical" or "mounting" than actual "electrical".
"50W into 8 ohm amps" will by definition take about same rail voltages; like Enzo often says: "the amplifier is just that thingie between the power supply and the speaker"
https://www.diyaudio.com/community/threads/fisher-cp-7000-distortion.382341/page-2#post-6930449
He put transistor boards in place of STK.
Given that there is a chip shortage, and supplies are too likely fake, this is a good solution.
Delhi and Bombay many suppliers are there, you may have known sources, ask your local repair people, the Mosfet boards are 600-800 range ($8-11), that is for stereo board, you need only one.
He put transistor boards in place of STK.
Given that there is a chip shortage, and supplies are too likely fake, this is a good solution.
Delhi and Bombay many suppliers are there, you may have known sources, ask your local repair people, the Mosfet boards are 600-800 range ($8-11), that is for stereo board, you need only one.
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Oh, if you want a complete amp also there are 80W Mosfet amps sold for 4500 - $60 - range here, with the usual FM/USB/Bluetooth kit.
They start at about 750 - 10$ - here for low power ones.
STK4141 set is about 1500 here - 20 USD. Chinese STK...
Kerala prices tend to be higher.
And in Kerala, plenty of Gulf returnee sets will be available...
They start at about 750 - 10$ - here for low power ones.
STK4141 set is about 1500 here - 20 USD. Chinese STK...
Kerala prices tend to be higher.
And in Kerala, plenty of Gulf returnee sets will be available...
Thanks for the detailed info @NareshBrd. However the issue was not stk chip, it was the faulty connectors to the speaker selection boards and faulty speaker selction switches. I replaced them and now its working like a charm.
made my day 🙂
on another note anyone knows a cheap DAC which adds bluetooth into this system.
Bluetooth pre amp, about 350 - $5 - here, it is the usual FM Module kit in a housing, with built in power supply, and RCA out.
You connect it to one of the inputs on the amp.
You connect it to one of the inputs on the amp.
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https://www.amazon.in/ERH-India-Blu...&hvtargid=pla-1188803149375&psc=1&ext_vrnc=hi
https://www.amazon.in/Salcon-Electr...1&hvtargid=pla-1212751506930&ext_vrnc=hi&th=1
These are the FM modules, they can use memory cards, USB sticks, Bluetooth and aux also.
Instead of making holes in your Sony system, it is better to use these, the price here with remote is about 120, $1.50, for the better quality kit, there is a cheaper one available.
You can use a 5V power supply from cell phone charger, and make a housing, and so on if you feel like.
This is sold in assembled form, as described above, which is time and money saving.
https://www.amazon.in/Salcon-Electr...1&hvtargid=pla-1212751506930&ext_vrnc=hi&th=1
These are the FM modules, they can use memory cards, USB sticks, Bluetooth and aux also.
Instead of making holes in your Sony system, it is better to use these, the price here with remote is about 120, $1.50, for the better quality kit, there is a cheaper one available.
You can use a 5V power supply from cell phone charger, and make a housing, and so on if you feel like.
This is sold in assembled form, as described above, which is time and money saving.
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Thanks @NareshBrd btw any idea where to find a remote for this one. The motorised volume knob was really cool.
Existing remote died?
Some threads here, in this forum, I think. See if you can find one.
Otherwise you will have to program one, based on the receiving IC used. PIC, or Logitech.
Some threads here, in this forum, I think. See if you can find one.
Otherwise you will have to program one, based on the receiving IC used. PIC, or Logitech.
I forgot, these come with a remote, and those are 15-20 each, no problem if they die. About 25 cents US.
So you can leave your amp volume steady, and control with the pre-amplifier unit. No need for amp remote.
FM and USB quality is good, they will not play Ogg Vorbis or FLAC, MP3 up to 320 kbps is well played.
So you can leave your amp volume steady, and control with the pre-amplifier unit. No need for amp remote.
FM and USB quality is good, they will not play Ogg Vorbis or FLAC, MP3 up to 320 kbps is well played.