Hi everyone,
This is one of my favorites chip amp using STK4182II in bridged mode, it can bring high quality sound with low cost and excellent performance.
The power supply has dual voltage of 40V and 5A current capability, better use two 10000uF in filter stage for power supply.
Let´s built them and enjoy.
This is one of my favorites chip amp using STK4182II in bridged mode, it can bring high quality sound with low cost and excellent performance.
The power supply has dual voltage of 40V and 5A current capability, better use two 10000uF in filter stage for power supply.
Let´s built them and enjoy.
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Hi Ferchito, let me be one to reply to your post; seems guys here dont give much damn to STK chips, though they are reliable and very good sounding. I started with 4048XI, designed PCB for it, can acomodate two hybrids on it + bridging circuit. It sounds great. Gives 150W out with +,-60V, and sounds even better bridged, +,- 35V. What is your application for STKs..Cheers...Tom
Hi Tomom, I agree with you about STK chips performance, my application for this circuit is for my personal entertainment, I designed PCB for bridged circuit and use two STK's for stereo amplifier and It sounds very good.
Regards,
Actually they are not reliable. They don't have internal protection against short circuit, cannot drive low impedance load. Cheap STK-based amps don't have external relay at the output so they will fail very easily.
They are indeed good sounding (less fatigue than mos amp chips, even the Gainclone).
the feedback components set the passband gain.
I see 56k and 560r+100uF on both the non-inverting and the inverting sides.
This is ~40dB of gain.
Increase the 560r to ~1k5, will reduce the gain by about 10dB and also bring up the low bass output slightly.
You could experiment in using upto 2k4 for that 560r or reduce the 56k down towards 20k.
Existing non-inverting gain = 1 + 56k/560r = 101
Existing inverting gain = 56k/560r = 100
proposed gain = 1 + 56k/1k5 = 38.3 (+31.7dB)
or
1 + 20k/1k5 = 14.3 (+23dB)
I see 56k and 560r+100uF on both the non-inverting and the inverting sides.
This is ~40dB of gain.
Increase the 560r to ~1k5, will reduce the gain by about 10dB and also bring up the low bass output slightly.
You could experiment in using upto 2k4 for that 560r or reduce the 56k down towards 20k.
Existing non-inverting gain = 1 + 56k/560r = 101
Existing inverting gain = 56k/560r = 100
proposed gain = 1 + 56k/1k5 = 38.3 (+31.7dB)
or
1 + 20k/1k5 = 14.3 (+23dB)
Right, LM and TDA are prefered. Not because they are objectively better, but they have better marketing, especially thanks to third parties, who make money from them. They are easier available, and they are usually cheaper. Also the documentation takes less effort to find and understand.
The newer STK types are hard to get and expensive. The older types are still sold, although they have been out of production for a long time, at least from Sanyo. This makes people wary about what they get, and those types usually also have specs that cannot compare to the LM and TDA amps, whether audible or not. Most of them are only specified as 8 Ohm stable, too.
That's what would be deterring me from using them. (I'm in 4 ohm land.) Even more so in a BTL configuration, unless supplies had to be unusually low for some reason.
Hybrids like STKs can provide more output power than conventional chipamps (which are ICs). Their reliability record wasn't all that great though (with Technics' modules enjoying a noticeably better reputation), so after using a lot of them in the late '70s to mid-'80s, manufacturers gradually went back to more robust discrete designs. You may still find hybrids in low-end A/V receivers, though even there they're not as popular any more.
hi, im using an stk 4050 amp, i built this circuit: STK4050 STK4050V 200W Power Amp IC - Buy Online @ AmpsLab Seems the gain is a bit low....how would i increase it?
Im disagree with you, STK is the most reliable and less expensive power amplifier that would be make on thick film substrate, it's an power hybrid IC amplifier, Never can be displaced of any and all or monolytic IC yesterday and tomorrow, that's a fact.
I'd like to chime in here about older Sanyo STK ICs:
I have recently been using an amp board that is populated with members of the series STK41x1v where 1<x<9, the lower number e.g. STK4111v has very low output power while the "9" version STK4191v is rated at 50W+50W into 8 ohms (it's a 2-channel amp IC). I redesigned the power supply, moving it off of the amp board and using larger caps, CRC filtering, and a better rectifier. The distortion levels are respectable, although not as low as LM series amps, e.g. LM3886, especially above 1k Hz, but low enough to be a non-problem.
I have used the "9" chip into 4R loads and it seems to be fine, and doesn't generate all that much heat. I could likely increase the rail voltage, which is around +/-34VDC.
The sound is good, and I am planning to do more of these amps. I've already picked up a stock of them from Ebay, and they seem to be genuine (as advertised).
Not all STK chip amps are good - some have high distortion, but this series seems to have good sound and can be had for "cheap". Good for DIY use for sure!
-Charlie
I have recently been using an amp board that is populated with members of the series STK41x1v where 1<x<9, the lower number e.g. STK4111v has very low output power while the "9" version STK4191v is rated at 50W+50W into 8 ohms (it's a 2-channel amp IC). I redesigned the power supply, moving it off of the amp board and using larger caps, CRC filtering, and a better rectifier. The distortion levels are respectable, although not as low as LM series amps, e.g. LM3886, especially above 1k Hz, but low enough to be a non-problem.
I have used the "9" chip into 4R loads and it seems to be fine, and doesn't generate all that much heat. I could likely increase the rail voltage, which is around +/-34VDC.
The sound is good, and I am planning to do more of these amps. I've already picked up a stock of them from Ebay, and they seem to be genuine (as advertised).
Not all STK chip amps are good - some have high distortion, but this series seems to have good sound and can be had for "cheap". Good for DIY use for sure!
-Charlie
Just be careful not to short the output. All other chips that I have used, can get away with output short. It is difficult to prevent the short when you do the prototyping. Expensive STK amp will provide relay protection tho.
From the STK4191v datasheet:
Available time for load short-circuit (VCC =±35.5V, RL = 8R, f = 50Hz, PO = 50W): 2 seconds
There is no protection per-se in the circuit, so you have 2 seconds (give or take) to save the amp from destruction. This is a small but important window of time, enough to pull those sparky wires apart...
-Charlie
Available time for load short-circuit (VCC =±35.5V, RL = 8R, f = 50Hz, PO = 50W): 2 seconds
There is no protection per-se in the circuit, so you have 2 seconds (give or take) to save the amp from destruction. This is a small but important window of time, enough to pull those sparky wires apart...
-Charlie
THD doesn't correlate well with possible sound quality.
For STK, the "II" series has high distortion compared to the "V" series. If I'm not mistaken, they differ only in that the "V" series use a current mirror for the LTP. Current mirror can lower the THD but I think to some extent it "ruin" the sound. Some other STK with very very low THD implement cascode in the VAS. Same issue, the cascode doesn't always bring justice to the sound.
If you check the "history", those low distortion STKs have never got popularity. This will tell you something about sound perception.
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