hi people greetings from distance, have this old receiver with STK460 amplifier but isn't working good, one channel sounds distorted, want to replace entire amp section with TA2022 ( very cheap and easy to build ) class T chip amp and 90W X 2 compared to 30W original STK460, analyzing power supply and fits perfect to TA2022 specks. 25v 1500 ma per rail. 
need opinions about it before start.
need opinions about it before start.
Ideal replacements include STK459, STK460, STK461, STK463 which will keep your receiver's features intact, much unlike what will happen if you replace with a much different chip.
I say this because, usually the tone controls wrap around the power amp. However, If your tone controls are on a separate preamp board (or section), then many different amplifiers could be used.
Except these: LM3875, LM3876, LM3886, LM4780 and other overture chips contain the spike system limiter, which protects the chip at the cost of exacerbated clipping-like noise. . . which is exactly what you'd get if you run the voltage too low. Of the overture series, LM1876 is for that voltage, but that chip is very low power and has the spike system to make sure you won't enjoy the results at full blast.
Your TA2022 (and other digital amplifiers) could work, except that fm radio reception probably won't work after that, or would at least be a shorter range, plus some noise. So, for a receiver, you'd want a Class AB amplifier.
LM1875's could work, except that 4 ohm speakers might blow them up on that voltage. However, if you got 8 ohm speakers, then those could work. My TurboII schematic has LM1875 at that voltage.
TDA2050 can also do it.
TDA7293/4/5/6 can all work easily at that voltage.
On this list, the least likely to be fake is a Singapore TDA7295.
At that voltage, it can easily drive 4 ohm speaker to 45W, with 80W peak power available.
So can STK463, which is a lot easier to install.
And STK bass is better than the little chips (epic difference in output transistor size).
I say this because, usually the tone controls wrap around the power amp. However, If your tone controls are on a separate preamp board (or section), then many different amplifiers could be used.
Except these: LM3875, LM3876, LM3886, LM4780 and other overture chips contain the spike system limiter, which protects the chip at the cost of exacerbated clipping-like noise. . . which is exactly what you'd get if you run the voltage too low. Of the overture series, LM1876 is for that voltage, but that chip is very low power and has the spike system to make sure you won't enjoy the results at full blast.
Your TA2022 (and other digital amplifiers) could work, except that fm radio reception probably won't work after that, or would at least be a shorter range, plus some noise. So, for a receiver, you'd want a Class AB amplifier.
LM1875's could work, except that 4 ohm speakers might blow them up on that voltage. However, if you got 8 ohm speakers, then those could work. My TurboII schematic has LM1875 at that voltage.
TDA2050 can also do it.
TDA7293/4/5/6 can all work easily at that voltage.
On this list, the least likely to be fake is a Singapore TDA7295.
At that voltage, it can easily drive 4 ohm speaker to 45W, with 80W peak power available.
So can STK463, which is a lot easier to install.
And STK bass is better than the little chips (epic difference in output transistor size).
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Thanks for the advice. The STK module i want to replace for whatever chip amplifier basically is for the reason i can't get original ones. Bought 2 on eBay and one at digikey all of it was Chinese clones. Very poor sound quality and weird noises, not present on original came with the receiver, only have one bad channel. Maybe would be better fit a full transistor amplifier circuit besides chip amp.
Actually Daniel. the SPIKE protection circuitry does not work the way that you describe it. The SPIKE protection circuitry only triggers when the die temperature gets too high. You can clip Overture series all day long and not trigger the SPIKE protection system as long as the chip doesn't get too hot, and the chip will clip just like an unprotected amplifier.
And the SPIKE protection circuitry does not truncate or "clip" the sine wave. It actually varies the duty cycle, just like a digital servo system does. This variable duty cycle servo system is employed in the electronics of your car; it's how the idle air control valve is controlled.
Look at the datasheet; it has a drawing of the signal with the SPIKE protection circuitry activated. The sine wave has a section "missing." It does not work at all like conventional protection circuitry, which effectively limits maximum power output. And look at the "equivalent" schematic diagram; the SPIKE protection circuitry is just a "black box."
Digital servo systems are ubiquitous in industrial applications. Their use in audio circuitry is novel, as far as I know.
Using an Overture series chip in a lower voltage circuit is less likely to trip the SPIKE protection circuitry.
Finally, the 3886 is used commercially in lower voltage applications. Look inside a Bose Waveguide radio and tell me what you find.
And the SPIKE protection circuitry does not truncate or "clip" the sine wave. It actually varies the duty cycle, just like a digital servo system does. This variable duty cycle servo system is employed in the electronics of your car; it's how the idle air control valve is controlled.
Look at the datasheet; it has a drawing of the signal with the SPIKE protection circuitry activated. The sine wave has a section "missing." It does not work at all like conventional protection circuitry, which effectively limits maximum power output. And look at the "equivalent" schematic diagram; the SPIKE protection circuitry is just a "black box."
Digital servo systems are ubiquitous in industrial applications. Their use in audio circuitry is novel, as far as I know.
Using an Overture series chip in a lower voltage circuit is less likely to trip the SPIKE protection circuitry.
Finally, the 3886 is used commercially in lower voltage applications. Look inside a Bose Waveguide radio and tell me what you find.
Before trying a replacement, I suggest to cable out from the bad channel's IN+, with a bi-conductor cable (other conductor is ground) to an RCA jack (add a series cap to one of the conductors, just in case) and then eavesdrop on the thing simply by using it as an audio source.
If this works, then your preamp/tone board is not troubled.
Yes! The STK is a rather bog standard transistor amp simply enclosed in a big casing. A similar transistor amp can replace it for sure.
It is probably possible to use TDA7293, although definitely not with the datasheet schematic. If you're interested, I can make a schematic for this application, and the boards are plentiful.
It is also possible to use an STK chip if it is a 460, 461, 463, 465 in condition USED with the pins in slight disarray and some solder on them (aka, a "pull"), although it may take some time to find one in used condition, but it would be authentic.
If this works, then your preamp/tone board is not troubled.
Yes! The STK is a rather bog standard transistor amp simply enclosed in a big casing. A similar transistor amp can replace it for sure.
It is probably possible to use TDA7293, although definitely not with the datasheet schematic. If you're interested, I can make a schematic for this application, and the boards are plentiful.
It is also possible to use an STK chip if it is a 460, 461, 463, 465 in condition USED with the pins in slight disarray and some solder on them (aka, a "pull"), although it may take some time to find one in used condition, but it would be authentic.
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