If you feel like, use the inputs to the module to drive a populated board, with Class AB drive.
This module is a high voltage intermediate amplifier, driving the outputs, which will need checking as well.
Better do the radical surgery, even the outputs may be hard to replace if needed.
Much less trouble, more reliable, energy efficient also.
This module is a high voltage intermediate amplifier, driving the outputs, which will need checking as well.
Better do the radical surgery, even the outputs may be hard to replace if needed.
Much less trouble, more reliable, energy efficient also.
No magic smoke yet. It has been powered on multiple times now for troubleshooting purposes ofcourse.
This module will always break, certainly in class A amps because of the extra heat that is being generated. The lack of a heatsink and age doesn't help either. Logic dictates thas it is most likely broken. Will do some measurements later on.
The thought had crossed my mind. Turns out that these power transistors are not available any more. Seems to be a common problem with line of amps. I'm still investigating what a suitable replacement would be. One thing that I've found out is that the bigger brothers of this amp almost always will have blown out power transistors when the stk module gets defective. Other users of this amp will still have functioning power transistors after replacing stk module. How much "damage" is done is difficult to tell, certainly not up to the initial manufacturer specs.
This module will always break, certainly in class A amps because of the extra heat that is being generated. The lack of a heatsink and age doesn't help either. Logic dictates thas it is most likely broken. Will do some measurements later on.
The thought had crossed my mind. Turns out that these power transistors are not available any more. Seems to be a common problem with line of amps. I'm still investigating what a suitable replacement would be. One thing that I've found out is that the bigger brothers of this amp almost always will have blown out power transistors when the stk module gets defective. Other users of this amp will still have functioning power transistors after replacing stk module. How much "damage" is done is difficult to tell, certainly not up to the initial manufacturer specs.
Thanx for your advice either way.
Its been over a year trying to fix my Akai amp. Finally found this page.
As per my reading. This just may work for my 3042.
I just have to compare schematics. here is the list of compatible numbers with my notes
IC STK-3042/3062/ 3082 / Not 3044 15 pin STK3082
TO Confirm STK3062, STK3082, STK3102, STK3122, STK3152
STK3062II, STK3082II
Once I fix this STK the next STK in the same amp is the STK2250
If anybody has a PCB for sale in India pls let me know. With components better.
I do tons of SMD work. We only bothered to get a stencil in year 8.
I stick to using 1206 SMD resistors and caps. Very easy to do by hand.
Put some flux paste over the board. press the components in. And then go in with a fine tip t12 and lead.
As per my reading. This just may work for my 3042.
I just have to compare schematics. here is the list of compatible numbers with my notes
IC STK-3042/3062/ 3082 / Not 3044 15 pin STK3082
TO Confirm STK3062, STK3082, STK3102, STK3122, STK3152
STK3062II, STK3082II
Once I fix this STK the next STK in the same amp is the STK2250
If anybody has a PCB for sale in India pls let me know. With components better.
I do tons of SMD work. We only bothered to get a stencil in year 8.
I stick to using 1206 SMD resistors and caps. Very easy to do by hand.
Put some flux paste over the board. press the components in. And then go in with a fine tip t12 and lead.
You can get custom PCBs made in Bangalore, the designs are free to use, for equivalent chips.
Since you already do this kind of work, should be easy.
Try Universal in the electronics market off JC Road (towards City Market from Town Hall), he might have some in stock.
In 1990 he had three band switches in stock for a Philips AR197 that was last made in 1978. Worth trying.
Even easier, find a ready transistor amp board for your amp voltage, and fit it inside, max. 1500 Rupees. Comes with heat sink. Stereo.
Since you already do this kind of work, should be easy.
Try Universal in the electronics market off JC Road (towards City Market from Town Hall), he might have some in stock.
In 1990 he had three band switches in stock for a Philips AR197 that was last made in 1978. Worth trying.
Even easier, find a ready transistor amp board for your amp voltage, and fit it inside, max. 1500 Rupees. Comes with heat sink. Stereo.
Hello davidsrsb and fmmech_24 ,
So I have ordered a pcb with davidsrsb design not knowing that fmmech_24 had posted a design for the stk3102III. Overlook on my part. Now the question is if the two are compatible. I need an 3102III as my marantz amp has one. Looking at the schematics the circuit is identical (minus the resistor mod). The used components are of a different value and/or type. Will this make a big difference? Can I still use davidsrsb design in my situation?
Thank you.
Hi all, I have a few amps that use these chips and one has recently died. It uses the STK3152III, it’s a Crest Vs900 and I have confirmed it’s the chip. I have multiple other amps that do not work, I haven’t confirmed their issues are these chips, but regardless I’d like to have a couple dozen of these boards made up. I’m very new at having boards made, so I was hoping that you all could help me not make a mistake when placing my order. I ordered all of the parts for these boards and mistakenly didn’t read through the whole thread, so I didn’t see the change to 18k resistors. I plan on adding the 18k resistors to my next order, but in the meantime I plan on using some small 1/4w through hole resistors, any issue with that? Not sure if the resistors will produce enough heat to need a heatsink, specifically those resistors.
The chip in this Crest amplifier mounts to the back panel using a small clamp that gets screwed into place. I read a thinner board is better if using a heatsink. .6mm??? Do not use FR4 correct, go aluminum? Ceramic? PCBWAY best place to go? Any help with this would be greatly appreciated!
Dan
The chip in this Crest amplifier mounts to the back panel using a small clamp that gets screwed into place. I read a thinner board is better if using a heatsink. .6mm??? Do not use FR4 correct, go aluminum? Ceramic? PCBWAY best place to go? Any help with this would be greatly appreciated!
Dan
Okay thank you, I’ll have to check pricing out. If there is an amp where it is placed in a spot where there is no heatsink and no place for a heatsink I’m guessing a thicker board is preferred?
Do you see any issue with using 3 1/4w through hole resistors in place of the 0603? I’m sure they’d last forever, just curious if they should be attached to a heatsink.
Dan
Yeah that’s what I mean, just mount them vertically off of the board, but just clip the leads short and tack them to the pads meant for the 0603 devices. I found the gerber files already made up for the aluminum boards, I’m guessing they’re adequate at drawing heat from the components, I haven’t seen anyone mention over heating. They’d definitely be more robust than the alumina boards and the file is already made up. I’ll look into having both made, but as I already mentioned, I’m super new at having boards made and I’ll definitely find a way to screw it up lol.
Dan