hello,
someone in a recent thread mentionned stk4231. A local store clears stock, claiming to have original sanyo products. I would like to check marking against original sanyo
Any picture ? Tips ?
someone in a recent thread mentionned stk4231. A local store clears stock, claiming to have original sanyo products. I would like to check marking against original sanyo
Any picture ? Tips ?
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Buy 1 and test it.
Use a Variac and start with half voltage rails, load them, inject signal, watch for no overheating, reasonable waveforms only flat clippin g on top, etc, then repeat raising voltage by 10% each step.
I was burnt by a batch (100) TDA2050 which would pass lots of idle current and overheat under +/-22V rails (a typical value), waveforms clipped similar to a ramp wave (one way to show they do NOT stand applied voltage), but worked perfectly under +/-14V rails, which is TA2030 territory, yours might show a similar behaviour.
I trust testing 1000 times more than guessing, including visuals, which a faker MAY get right.
Hey, my fake TDA2950 look perfect, and yet .....
FWIW I am a silkscreener (for my PCBs and Front Panels), and a hobby photographer with a full BW Lab and if needed can perfectly reproduce and print an original looking label.
Good 2 component Epoxy ink stands the usual "swab with acetone" test, commonly used to detect fakes, and I am quite certain somebody with a not too expensive CNC Laser can laser etch "original" labels, so .....
If I can at home, imagine fakers!!!!
Use a Variac and start with half voltage rails, load them, inject signal, watch for no overheating, reasonable waveforms only flat clippin g on top, etc, then repeat raising voltage by 10% each step.
I was burnt by a batch (100) TDA2050 which would pass lots of idle current and overheat under +/-22V rails (a typical value), waveforms clipped similar to a ramp wave (one way to show they do NOT stand applied voltage), but worked perfectly under +/-14V rails, which is TA2030 territory, yours might show a similar behaviour.
I trust testing 1000 times more than guessing, including visuals, which a faker MAY get right.
Hey, my fake TDA2950 look perfect, and yet .....
FWIW I am a silkscreener (for my PCBs and Front Panels), and a hobby photographer with a full BW Lab and if needed can perfectly reproduce and print an original looking label.
Good 2 component Epoxy ink stands the usual "swab with acetone" test, commonly used to detect fakes, and I am quite certain somebody with a not too expensive CNC Laser can laser etch "original" labels, so .....
If I can at home, imagine fakers!!!!
The problem is that Sanyo used to supply chips marked 'stereo amplifier (part number)' for their OEM customers, and some of those used to end up as service parts at service centers.
No Sanyo marks on those, and totally genuine.
The replacement market would get Sanyo markings.
I have no data on the actual marking used, so spotting fakes is difficult.
Some Braille type dots were on the top face in Sanyo marked parts, and the original PCB was dark green epoxy.
Bear in mind that production stopped mid 90s, and very few original survive in the market.
Unless you have handled many, the 'feel' of the fakes is hard to spot.
And if the volume is large, fakes are made at the usual places...
My advice is to avoid buying those, unless essential.
Also, environmental damage and other factors can cause deterioration, and it may not work as well as expected.
No Sanyo marks on those, and totally genuine.
The replacement market would get Sanyo markings.
I have no data on the actual marking used, so spotting fakes is difficult.
Some Braille type dots were on the top face in Sanyo marked parts, and the original PCB was dark green epoxy.
Bear in mind that production stopped mid 90s, and very few original survive in the market.
Unless you have handled many, the 'feel' of the fakes is hard to spot.
And if the volume is large, fakes are made at the usual places...
My advice is to avoid buying those, unless essential.
Also, environmental damage and other factors can cause deterioration, and it may not work as well as expected.
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Oh, and one more thing, there are posts here and possibly in other forums about making equivalent STK modules using transistors, see those as well.
For a new build, stick to discrete or Class D, the Class AB chip amp is slowly going extinct.
For a new build, stick to discrete or Class D, the Class AB chip amp is slowly going extinct.
I have original Sanyo STK and OEM. I can't tell the difference.I would like to check marking against original sanyo
Any picture ? Tips ?
Here's a STK4241mk2 by PMC. According to their datasheet, it's 120W+120W into 8 ohms.
That's pushing it for one pair of power transistors.
I de-rated it to 65W into 8 ohms and 100W into 4 ohms.
Stable. No oscillations.
Derating is good and safe in general, and even more if suppliers are not fully trusted.
In any case, measuring, if possible, is safest.
In any case, measuring, if possible, is safest.
Here's the power output - 10kHz into 8 ohms.
Measured a 67.2Vp-p.
And this is the 10khz Square Wave into 8 ohms a 10Vp-p.
Measured a 67.2Vp-p.
And this is the 10khz Square Wave into 8 ohms a 10Vp-p.
Very interesting : thanks for all the contributions.
Osvaldo de Banfield had mentionned this chip in other thread. I never played with sanyo amps. It's just opportunity for hobby 😉. Here is the chip :
Osvaldo de Banfield had mentionned this chip in other thread. I never played with sanyo amps. It's just opportunity for hobby 😉. Here is the chip :
I buy HGSemi TDA2050 from LCSC, they are perfectly fine. They have a clean datasheet (a copy from the ST one...) but the chips are ok. If you are still looking for TDA2050 you should try them.
HGSemi has a catalog with a lot of standard parts, which are copies but genuine, not fake parts from some marketplaces, at least from my experience.
Osvaldo, which chip are you talking about, is it the HG Semi 2050?
And tell us what you think of the STK in the above picture, the PCB at least looks okay.
And it does look like the original Triangle 2050 is adequate in terms of die size, and there are Chinese fakes of Chinese chips, which is hard to deal with.
And tell us what you think of the STK in the above picture, the PCB at least looks okay.
And it does look like the original Triangle 2050 is adequate in terms of die size, and there are Chinese fakes of Chinese chips, which is hard to deal with.
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If you do buy the STK, please note that they were famous for blowing up, taking out speakers and power supplies as well.
Use proper heat sink, less than 75% of voltage rating on supply, and speaker protection of some sort.
And fast blow fuses.
The STK sound is unique, and properly used they are very good.
Now they are long out of production, and alternates are available.
Use proper heat sink, less than 75% of voltage rating on supply, and speaker protection of some sort.
And fast blow fuses.
The STK sound is unique, and properly used they are very good.
Now they are long out of production, and alternates are available.
I don't remember exactly. I used several of them. I started with STK 432 with single power rail. Thus I moved to dual suppy actually in use for home listening. But I used other for background music on supermarkets replacing discrtete solutions. But those was 10 or 15 years ago and my memory lacks those part numbers. They were one for 120/150W range.
It is the same as the STK4241mk2, slightly lower power at 100W 8 ohm instead of 120W 8 ohm.
I think the STK4231mk2 was discontinued when the 4241mk2 came out.
The two models are pin compatible. Same circuit too.
There's only one pair of power transistors per channel arranged in quasi-complementary.
That's the reason I de-rated it to 65W into 8 ohms. With a lower voltage, the STK4241mk2 will be able to operate at 100W into 4 ohm comfortably.
I have created an audio amplifier using STK4231 and I am pretty sure I did purchase a clone version of the IC from a local market here in Sri Lanka. But surprisingly it never gave any issues or no any audible quality problem in sound too.
I've created a video just by combining some random video clips taken through the video:
A demonstration of the audio quality of it (used a Sony speaker system):
I've created a video just by combining some random video clips taken through the video:
A demonstration of the audio quality of it (used a Sony speaker system):
Don't change the volume suddenly on clone chips, they can burn, taking the speakers and power supply as well.
Otherwise they are at times an improvement in the original STK, quite well made at times.
There seem to be many makers in China, quality may vary from one to other.
I use the volume control on Winamp, the pot on amp is left at about 10 O'Clock, full is 5 O'Clock.
This saves wear on it, and less chance of crackle...
Otherwise they are at times an improvement in the original STK, quite well made at times.
There seem to be many makers in China, quality may vary from one to other.
I use the volume control on Winamp, the pot on amp is left at about 10 O'Clock, full is 5 O'Clock.
This saves wear on it, and less chance of crackle...
Hi rasansmn,
Where did you bought spectrum analyser. I'm impressed to your project especially analyser. Please let me know.
@rameshaudio I made it using LM324 based driver unit and seven KA2284 level indicators. The PCBs were available in the local market to purchase. If you need the schematic diagram of it, let me know.