I still have an old AKAI slim looking power amp, with two STK 0050 on the output. It had switching power supply, (to make it slim and light), which died. I put big trafo and real power suply on it, and it sounds great. It has beautiful fluorescent power meter, nice to look at, that was the only reason I resurected it.
Recently I compared the AKAI to discrete amps, some JVC (SuperA) amps and old NIKKO. NIKKO beat them all, but AKAI did not sound that bad. I am using it in bi-amp system to power woofers, it can put out 50 watts, which is more than plenty. With tube amp on mid/treble, system sounds great, plus I have nice fluorescent indicator to look at. Otherwise I had some other stuff with STK modules, old Technics receiver, still working day and night in the lab, and some other ECO? or EICO? That limits my experience with STK modules. I guess they can sound decent, but it does not compare to well designed discrete transistor amp. That applies to LM series amps as well. I built few of those chipmunks, they sound ok, but they are not krell or parasound, that's for sure.
Recently I compared the AKAI to discrete amps, some JVC (SuperA) amps and old NIKKO. NIKKO beat them all, but AKAI did not sound that bad. I am using it in bi-amp system to power woofers, it can put out 50 watts, which is more than plenty. With tube amp on mid/treble, system sounds great, plus I have nice fluorescent indicator to look at. Otherwise I had some other stuff with STK modules, old Technics receiver, still working day and night in the lab, and some other ECO? or EICO? That limits my experience with STK modules. I guess they can sound decent, but it does not compare to well designed discrete transistor amp. That applies to LM series amps as well. I built few of those chipmunks, they sound ok, but they are not krell or parasound, that's for sure.
When inputs are mentioned, it invariably means signal inputs designated as +Vin and -Vin. The datasheet of STK4182 does not show these pins.
For every channel, there are two input pins. For thia STK, it is pins 1and 2 for one channel and pins 17 and 18 for the other channel. When it is working, the voltage diffrence between these pins will be low. This confirms that the internals of the amp are working.
For more about 2 input pins for each channel, see LM4780 datasheet.
Gajanan Phadte
For every channel, there are two input pins. For thia STK, it is pins 1and 2 for one channel and pins 17 and 18 for the other channel. When it is working, the voltage diffrence between these pins will be low. This confirms that the internals of the amp are working.
For more about 2 input pins for each channel, see LM4780 datasheet.
Gajanan Phadte
STK401 140 is a high power module and has same pin connections and the application schematic as of 120. It should work.
Confirm for yourself and use.
STK401-120 pdf, STK401-120 description, STK401-120 datasheets, STK401-120 view ::: ALLDATASHEET :::
STK401-140 pdf, STK401-140 description, STK401-140 datasheets, STK401-140 view ::: ALLDATASHEET :::
Gajanan Phadte
Confirm for yourself and use.
STK401-120 pdf, STK401-120 description, STK401-120 datasheets, STK401-120 view ::: ALLDATASHEET :::
STK401-140 pdf, STK401-140 description, STK401-140 datasheets, STK401-140 view ::: ALLDATASHEET :::
Gajanan Phadte
Hi, I'm new on this forum (great stuff, can't believe i haven't found it earlier!) because I found a STK 402-040 module on a heavily damaged circuitboard I salvaged. When I researched it the specs looked quite promising so I decided to have some fun and build the application circuit provided by Sanyo. This thing rocks! It sounds very good with generous bass and brilliant mids and highs. Now I'm hooked! I'm already rebuilding the circuit into something presentable which i will post in this forum when finished.
In my research I found that Sanyo recently became part of ON-semi, ditching all old versions of the Stk series and coming up with a new line of STK 433-xxx that have on-board standby circuits i'm not sure existed in previous versions. If anyone has experience with them please let me know, I'll try one when my current build is done and post that also.
So, to answer this topic's question: Yes. STK's can sound very well! I'm impressed by the one I found and I suspect there are better sounding series.
DrZ.
In my research I found that Sanyo recently became part of ON-semi, ditching all old versions of the Stk series and coming up with a new line of STK 433-xxx that have on-board standby circuits i'm not sure existed in previous versions. If anyone has experience with them please let me know, I'll try one when my current build is done and post that also.
So, to answer this topic's question: Yes. STK's can sound very well! I'm impressed by the one I found and I suspect there are better sounding series.
DrZ.
There are some warnings in order though:
They're essentially unprotected devices, theý will happily release "the smoke" when mistreated. No failsafe in there. Also, keep ground as close as possible and install all necessary anti-oscillation components as they seem to oscillate pretty easy without zobels and decoupling caps right on top of the stk's leads. When I tested it without the zobel networks on the outputs it almost fried itself...
They're essentially unprotected devices, theý will happily release "the smoke" when mistreated. No failsafe in there. Also, keep ground as close as possible and install all necessary anti-oscillation components as they seem to oscillate pretty easy without zobels and decoupling caps right on top of the stk's leads. When I tested it without the zobel networks on the outputs it almost fried itself...
I like the absolute silence when it's on and therefore the ability to play at very low levels without drowning in noise. The amp I'm now building with it will be a cool running, underpowered and very small workspace amp. Nothing fancy. I suspect it will do nicely with a pair of jbl control 1.
I have an amplifier already built and has been modified for other uses
using the STK 4141v HERE...HTP 25/25 Full Range Amp
Dual 25 Watt
FOR $19.95..
Also the STK 4038 and STK 4041 both listed on my website
using the STK 4141v HERE...HTP 25/25 Full Range Amp
Dual 25 Watt
FOR $19.95..
Also the STK 4038 and STK 4041 both listed on my website
My first tryout for a cpu cooler based stk amplifier. I think the stk modules are perfect for being cooled by cpu heatsinks as they are very similar to cpu's in both form and heat dissipation requirements. This is an intel stock cooler, the fan is just for mounting the heatsink and is not operational. It is not needed because it's a low power amp and the heatsink barely gets warm when playing at neighbour-friendly sound levels.
Attachments
According to my local, respected electronics shop the 402-070 can be ordered. I did. He also confirmed they are genuine Sanyo. They should arrive tomorrow, I'm confident it will be the real deal. Might be old stock or service parts.
Also, Sanyo semi was acquired by ON-semi and they have some stk's in their current catalog:
http://www.onsemi.com/PowerSolutions/search.do?action=addParam¶mName=paramString¶mVal=Audio%20Amplifiers%3aClass%20AB%3a2502766
Also, Sanyo semi was acquired by ON-semi and they have some stk's in their current catalog:
http://www.onsemi.com/PowerSolutions/search.do?action=addParam¶mName=paramString¶mVal=Audio%20Amplifiers%3aClass%20AB%3a2502766
Got it! I can confirm this is a 100% genuine Sanyo stk chip, not a fake. They have lots and lots of them in stock and by the looks of it On-Semiconductor is planning to release more STK series. Maybe they can bring some order in the chaos that is the STK family? My main focus will be on the 402-xxx series as they are symmetrical, small and powerfull. I'm designing a custom pcb for it with short-as-possible routing and optimal component placement for use in a series of amplifiers I'm planning to build. New life for the unique hybrid amplifier that is the STK chip.
Correct. The bad reputation these hybrids have is largely because of terrible design of these entry and midlevel consumer electronics. The kenwood unit I pulled a 402-040 out of suffered from horrible pcb design, lots of wirebridges, flatcables and too small heatsink. Also it had numerous opamps, dsp's and unnecessary filtering caps all across the board. No way that can produce good clean sound. Must have sounded dull, bland and wooly. Now that it's freed of that surrounding and built on a gainclone like pcb with ultra short signal paths and no additional filtering or long cables it is a most revealing little amp. Very accurate reproduction, no hiss or hum and excellent clarity. Everything you would expect from a well designed class AB amp. Also, by cooling it properly with a cpu cooler it barely gets warm so there's no risk of frying it when put under stress. I suspect a lot of the premature failures are due to bad cooling designs and mismatched speakers. These hybrids really don't like low impedance loads, 6 ohms is the lowest they can do without burning up but they are at their best with 8 ohm high eff speakers. I really can advocate experimentation with them, for instance: most brands like sony, kenwood, yamaha etc simply use the application note schematic. I'm sure that with some experimentation the results could be much better. My research into STK's is ongoing and so far I like what I'm seeing (and hearing) so expect more updates from me on this topic.
Hi, about the STK power chip ,
I know the STK-084 50w chips are used in Electro-Voice (EV) Sentry 100EL powered monitor speaker system. (not active speaker, it use passive crossover)
These speaker are made for recording studio , and in that year I know some studio are quite like it's sound quality!
I know the STK-084 50w chips are used in Electro-Voice (EV) Sentry 100EL powered monitor speaker system. (not active speaker, it use passive crossover)
These speaker are made for recording studio , and in that year I know some studio are quite like it's sound quality!
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