Hi people,
I am looking to build myself a small stereo power amp based on the STK integrated amp modules, I think they are made by Sanyo?
Anyway, I am looking for any advice anyone has on them, and opinions from people who have used them.
I am currently thinking of either using the STK-443 which is rated at 25+25 W at 8 ohms and a Vcc of 49V, or a couple of STK-084 or -086 which are mono and rated at 50W and 70W respectively at 8 ohms, and a Vcc of 35V and 42V respectively.
I personally would rather use two mono units, simply for the extra power and the fact there are less components packed into the case. I have heard that the stereo modules can be run mono in bridge mode, but I don't know how it affects their tone or reliability. Also, can I run these amps in parallel?
I want to use chip amps because of their compactness, as the case I have is limited in space. I'm not going to be spending a fortune on this project, I just have a really attractive wooden cabinet and chassis and faceplate from an old 70's stereo amp that was fried, and I just want to replace all the internals with modern stuff so it is still useable and doesnt sound awful.
If anyone has anything helpful to add, by all means do so
Josh
I am looking to build myself a small stereo power amp based on the STK integrated amp modules, I think they are made by Sanyo?
Anyway, I am looking for any advice anyone has on them, and opinions from people who have used them.
I am currently thinking of either using the STK-443 which is rated at 25+25 W at 8 ohms and a Vcc of 49V, or a couple of STK-084 or -086 which are mono and rated at 50W and 70W respectively at 8 ohms, and a Vcc of 35V and 42V respectively.
I personally would rather use two mono units, simply for the extra power and the fact there are less components packed into the case. I have heard that the stereo modules can be run mono in bridge mode, but I don't know how it affects their tone or reliability. Also, can I run these amps in parallel?
I want to use chip amps because of their compactness, as the case I have is limited in space. I'm not going to be spending a fortune on this project, I just have a really attractive wooden cabinet and chassis and faceplate from an old 70's stereo amp that was fried, and I just want to replace all the internals with modern stuff so it is still useable and doesnt sound awful.
If anyone has anything helpful to add, by all means do so
Josh
hello.
some years ago i have used the stk 439 and stk 460.and i had a receiver with stk 084g and a fisher amp with stk4171.........
the sound was acceptable...............but i think they die suddenly when there is a short at the output.
nowadays i prefer the national lm types (1875,1876,3886......) over the stk's, because they are cheap,tiny,easy available and with a good psu they sound amazingly well.
greetings................
some years ago i have used the stk 439 and stk 460.and i had a receiver with stk 084g and a fisher amp with stk4171.........
the sound was acceptable...............but i think they die suddenly when there is a short at the output.
nowadays i prefer the national lm types (1875,1876,3886......) over the stk's, because they are cheap,tiny,easy available and with a good psu they sound amazingly well.
greetings................
The STK modules don't sound very good, and have too many external components (they run a bootstrap externally, as well as some part of the current mirror I guess). This usually makes for messy layouts.
With some care one can lay it out for minimal ground noise (the PCBs in the datasheet are terrible!), but the fidelity is still pretty low. I find the LM series sounds a whole lot better, even some of the TDA chips have better sound.
Most STKs currently available are fake, Sanyo stopped production quite a while ago. You're either getting NOS or NOK-OFF. Caveat Emptor.
I've used a lot of their amps in the past (41xx, 43xx) and at the time (90s) there were no chips available to compete with them. But there are better options now for sure.
And the STKs absolutely collapse in bridged mode. I was running a pair of STK4191 as bridge amps for a long time. I pulled it out for a listen recently, and I was appalled at the sound.
I would really look at something else, and this is coming from an ex-STK fanboy.
With some care one can lay it out for minimal ground noise (the PCBs in the datasheet are terrible!), but the fidelity is still pretty low. I find the LM series sounds a whole lot better, even some of the TDA chips have better sound.
Most STKs currently available are fake, Sanyo stopped production quite a while ago. You're either getting NOS or NOK-OFF. Caveat Emptor.
I've used a lot of their amps in the past (41xx, 43xx) and at the time (90s) there were no chips available to compete with them. But there are better options now for sure.
And the STKs absolutely collapse in bridged mode. I was running a pair of STK4191 as bridge amps for a long time. I pulled it out for a listen recently, and I was appalled at the sound.
I would really look at something else, and this is coming from an ex-STK fanboy.
Flyingtele,
Not sure if the following is any use to you, but here's my take on one particular STK:
I have a STK4141-II (part of an old Sansui receiver). I don't know how that compares to what you're looking at.
So far, I've bypassed everything but the tone controls. Not even an input selector or Vol (I'm controlling volume at my FLAC player, which is my only source). I'm running 90mm full-range, near-field monitors.
At the moment, the STK won't go loud without taking on a hard edge and losing bass depth, control and tune.
At lower volume I'm getting a lot of detail and 'ambiance.' It's toe-tappy and moderately tuneful -- even in the bass. A couple of hours warm up makes a big difference. I have some bigger P/S caps to fit -- hopefully that will help too.
Maybe I wasn't expecting much from something I found on the street, but I am impressed.
On the other hand: look at all the user feedback on the National chips.. People really love them.
When I get some money, I'll be trying one for myself.
Not sure if the following is any use to you, but here's my take on one particular STK:
I have a STK4141-II (part of an old Sansui receiver). I don't know how that compares to what you're looking at.
So far, I've bypassed everything but the tone controls. Not even an input selector or Vol (I'm controlling volume at my FLAC player, which is my only source). I'm running 90mm full-range, near-field monitors.
At the moment, the STK won't go loud without taking on a hard edge and losing bass depth, control and tune.
At lower volume I'm getting a lot of detail and 'ambiance.' It's toe-tappy and moderately tuneful -- even in the bass. A couple of hours warm up makes a big difference. I have some bigger P/S caps to fit -- hopefully that will help too.
Maybe I wasn't expecting much from something I found on the street, but I am impressed.
On the other hand: look at all the user feedback on the National chips.. People really love them.
When I get some money, I'll be trying one for myself.
Sweet, thanks for your help. Ill probably opt for an LM series chip amp from National. Can I run two off one power supply if its properly regulated, and has big enough rail caps and a transformer with enough juice?
Some amps work fine like that, yet others like the ETI 480 don't seem to like it.
As previously stated, its not for ultimate hi-fi, rather just bringing an attractive old amp back to life with new circuitry. For the pre amp I plan on using an LM1036 chip which is a stereo volume-bass-treble-balance control all in a single package.
Some amps work fine like that, yet others like the ETI 480 don't seem to like it.
As previously stated, its not for ultimate hi-fi, rather just bringing an attractive old amp back to life with new circuitry. For the pre amp I plan on using an LM1036 chip which is a stereo volume-bass-treble-balance control all in a single package.
There is a huge number of STK power output modules, with diferent toppologies, so is their quality (sound). STK4048XI is a very good one, 16 transistors in all with long tail pair and current mirror; I made amp with it and sound great, lot of power (150W) and good bass...STK084, 086 have much simple design with 9 transistors ...good for guitar amp...
Hello, i was also considering the same STK series but after looking at what others are saying Im looking into more info. I was considering the STK433-130-E or 150-E series. not many parts needed to make. look at data sheet for schematic and applications. also can be bridged as well. hope this helps
Hi people, would anyone care to comment (out of experience, preferably) on the STK0050-II? I have two of these in a Marantz SR5100 and am just curious at the way Marantz wired it up to the two transistors... Do they use the transistors as protection?
thank you
ps: sorry for some odd reason I am not able to upload a schematic. maybe it's IE9...
thank you
ps: sorry for some odd reason I am not able to upload a schematic. maybe it's IE9...
Hi,
STK 0050 - VBE, driver and output. Datasheet: STK0040 datasheet pdf datenblatt - List of Unclassifed Manufacturers - OUTPUT STAGE OF AF POWER AMP ::: ALLDATASHEET ::: among many other STK's
STK 0050 - VBE, driver and output. Datasheet: STK0040 datasheet pdf datenblatt - List of Unclassifed Manufacturers - OUTPUT STAGE OF AF POWER AMP ::: ALLDATASHEET ::: among many other STK's
Attachments
the STK433-130 still lives through MCM electronic store for $10.51 and about average at a few other stores i see online... so they are still out there. here is the website to place a order the STK433-130.
Sanyo Thick Film Hybrid IC 2 Channel Class AB Audio Power IC, 150W x2 | STK433-130-E (STK433130E) | Sanyo
Hope this helps. also you can get the schematic to build this amp and also in blt mode as well for 300 watts RMS (or near).
Sanyo Thick Film Hybrid IC 2 Channel Class AB Audio Power IC, 150W x2 | STK433-130-E (STK433130E) | Sanyo
Hope this helps. also you can get the schematic to build this amp and also in blt mode as well for 300 watts RMS (or near).
STK specs
I'm reluctant to resurrect an old thread.. and especially since this is my first post on the forum... Does anyone have a reference for specs on the various STK amps? Do the numbers indicate anything other than just a model #? I have an old Realistic STA-785 receiver (mid '80s vintage) that I left powered on for a couple days with the volume down and totally improper speakers attached. Receiver doesn't "amp" any more. I'm wondering whether to suspect the STK4182II. I find replacements on eBay, etc. I'm really new to electronics testing. Is there a novice guide to simple testing with a VOM?
I'm reluctant to resurrect an old thread.. and especially since this is my first post on the forum... Does anyone have a reference for specs on the various STK amps? Do the numbers indicate anything other than just a model #? I have an old Realistic STA-785 receiver (mid '80s vintage) that I left powered on for a couple days with the volume down and totally improper speakers attached. Receiver doesn't "amp" any more. I'm wondering whether to suspect the STK4182II. I find replacements on eBay, etc. I'm really new to electronics testing. Is there a novice guide to simple testing with a VOM?
Power inputs? Signal inputs? Referencing a sample circuit, looks like the STK4182II has +Vcc on pin 11. -Vcc should hit pins 14 and 9. 10 and 13 are R/L speaker +. 1 and 18 are R/L signal inputs. 3, 16 grounded.
http://www.datasheetcatalog.org/datasheet/sanyo/STK4182.pdf
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