Fake STK3152/STK3102

I think you mean aluminium oxide or alumina ceramic. They would be better thermally. Unfortunately you cannot get these made by the cheap Chinese fabs.

Photos of the original show that there was little attempt to used large copper pads to actually benefit from the substrate heatsinking and the standard fault of the high voltage and power dissipation thick film resistor going high value shows that the thermal design was poor
 
Hello !
I recently purchased a defective Marantz PM80 MK1 amplifier. The STK3102 IV module in this amp has a short in it. The amp also came with one of the replacement PCBs discussed in this thread. The PCB is marked "2018 DJBP substitute STK3102". I believe the original owner got the PCB from a DIY Audio forum member. Two questions (for now) if I may?

1) Is the substitute module discussed in this thread a drop in replacement for the STK3102 version IV model or is the application only suited to replace a version III ?

2) Is the 2018 PCB blank I have fit for purpose or should I go with the latest version and BOM mentioned in the thread above?

Many Thanks - Barry
 
I have no information about the Version IV, if you can find any information,I will have a look

I've not been able to find a datasheet for the IV version, but it seems that the III version will work in its place. That is actually implied at the start of this thread. I'm going to order up some of your boards and give it a whirl. Thanks very much to you for providing a solution to this problem.
 
Interesting project. I was looking to make a board for my marantz pm52 wich i have recently repaired with a clone skt3082 from reichelt.de. It appears to be working but hearing the story on fakes, better be safe and try a nice weekendproject.

I was ordering parts on farnell but had trouble finding the zxtp5401gta on that site. what could be a suitable replacement for that?
 
Helo all
Than you David for a great job makeing clone of stk3102.
I am working on AKAI_AM-U04_AM-2250 and planing to make the clone
Someone can sell me the pcb board? someone made it .....
I am in croatia (EU)
Regads David

vizkoze
I think this can replace the original ones in the sch
ZXTP5401FL 150V, SOT23, PNP High voltage transistor
BVCEO > -150V BVEBO > -5V IC(cont) = -600mA PD = 330mW
Complementary part number ZXTN5551FL
 
PNP Cross ref
BTB1236AL3 Si PNP 5 160 1.5 140 60 SOT223
BTB1238AL3 Si PNP 3 240 1 140 120 SOT223
CZT5401E Si PNP 2 220 0.6 100 100 SOT223
ZXTP03200BG Si PNP 3 200 2 105 100 SOT223
ZXTP5401G Si PNP 2 150 0.6 100 60 SOT223

NPN Cross ref
BTC2881L3 Si NPN 6 200 1 120 160 SOT223
BTC3906L3 Si NPN 5 160 0.6 100 120 SOT223
BTD1857AL3 Si NPN 5 160 1.5 140 160 SOT223
CHT2000ZGP Si NPN 2 200 0.6 3000 SOT223
CHT5551ZGP Si NPN 2 160 0.6 100 80 SOT223
CZT2000 Si NPN 2 200 0.6 3000 SOT223
CZT5551E Si NPN 2 220 0.6 100 120 SOT223
CZT5551HC Si NPN 2 160 1 100 80 SOT223
DZT5551 Si NPN 1 160 0.6 100 80 SOT223
PZT5551 Si NPN 1.5 160 0.6 100 80 SOT223
PZT5551L3 Si NPN 5 160 0.6 100 120 SOT223
STC2073Q Si NPN 1.5 160 1 150 200 SOT223
ZXTN5551G Si NPN 2 160 0.6 130 80 SOT223

PNP SMD Codes
2L MMBT5401 Si-pnp HV, 160V, 200mA, 350mW, B=60..240, >100MHz SOT-23 16ta 3a - Nsc,Vs
2L TMPT5401 Si-pnp GP, 160V, 200mA, 350mW, B=60..240, >100MHz SOT-23 16ta 3a - All
-2L PMST5401 Si-pnp HV, 160V, 300mA, 200mW, B=60..240, 100..300MHz SOT-323 16ta 3a - PhH
C2L CMPT5401 Si-pnp GP, 160V, 500mA, 350mW, B=60..240, 100..300MHz SOT-23 16ta 3a - Cen
K4M MMBT5401 Si-pnp HV, 160V, 200mA, 350mW, B=60..240, >100MHz SOT-23 16ta 3a - Di
p2L PMBT5401 Si-pnp HV, 160V, 300mA, 250mW, B=60..240, 100..300MHz SOT-23 16ta 3a - PhM
t2L PMBT5401 Si-pnp HV, 160V, 300mA, 250mW, B=60..240, 100..300MHz SOT-23 16ta 3a - PhH
t2L PMST5401 Si-pnp HV, 160V, 300mA, 200mW, B=60..240, 100..300MHz SOT-323 16ta 3a - PhM
ZE 2N5401S Si-pnp GP, 150V, 600mA, 350mW, B=60..240, >100MHz SOT-23 16ta 3a - Kec

NPN SMD Codes
1FF CMPT5551 Si-npn Sw, 180V, 600mA, 350mW, B=80..250, 100..300MHz SOT-23 16ta 3a - Cen
3S MMBT5551 Si-npn HV, 180V, 200mA, 350mW, B=80..250, >300MHz SOT-23 16ta 3a - Nsc,Vs
G1 MMBT5551 Si-npn HV, 180V, 200mA, 350mW, B=80..250, >300MHz SOT-23 16ta 3a - Bel,Mot
-G3 PMST5551 Si-npn HV, 180V, 300mA, 200mW, B=80..250, 100..300MHz SOT-323 16ta 3a - PhH
K4N MMBT5551 Si-npn HV, 180V, 200mA, 350mW, B=80..250, >300MHz SOT-23 16ta 3a - Di
K4N MMST5551 Si-npn GP, 180V, 200mA, 200mW, B=80..250, <300MHz SOT-323 16ta 3a - Di
N80 SO5551 Si-npn GP, 180V, 200mA, 200mW, B=80..250, <300MHz SOT-23 16ta 3a - Ste
O80 SO5551R Si-npn GP, 180V, 200mA, 200mW, B=80..250, <300MHz SOT-23R 16te 3a - Ste
pG1 PMBT5551 Si-npn GP, 180V, 300mA, 250mW, B=80..250, 100..300MHz SOT-23 16ta 3a - PhM
tG1 PMBT5551 Si-npn GP, 180V, 300mA, 250mW, B=80..250, 100..300MHz SOT-23 16ta 3a - PhH
tG3 PMST5551 Si-npn HV, 180V, 300mA, 200mW, B=80..250, 100..300MHz SOT-323 16ta 3a - PhM
ZF 2N5551S Si-npn GP, 160V, 600mA, 350mW, B=80..250, >100MHz SOT-23 16ta 3a - Kec
 
Last edited:
A minor update, the high voltage dropper resistors that burned out in the original are now each split into 3 series parts to spread the heating.
Further increases in the copper on the output driver transistors
 

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hi dzevo,
as requested a picture of the 4 black 0.6mm pcbs, including 1 pcb with attached BGA heatsink


BR
Günni
 

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Heatsink

Interesting that the topic of heat sinks has come up. I purchased a small heat sink and used the self adhesive tape it came with to fix the heat sink to the back of the module.

The heat sink doesn't seem to do much. The transistors run hot (like too hot to touch) but the heat sink is cool.

Please can I ask what is the preferred method to fix the heat sink to the back of the module?
 
Have been interested in this thread because my Sony str-av1020 lost the left channel and developed distortion in the right due to the failure of the stk3122-3 after only 30 years.... This receiver has had other problems with bad crimped connections on internal wiring so has been on the bench several times before but the main amplifier has always been awesome and will produce about double its rated 120w per channel into a load resistor. Naturally I wanted to fix it again and found a NOS on ebay for $18. When it arrived, I noticed it had evidence of being de-soldered but it works fine so maybe they actually did test it first...... (rolls eyes) It is the genuine part though, even has the production codes printed on the back side and was absolutely pristine as far as being clean and free of any wear or other marks so maybe I got lucky.

Anyhow... I loved this thread and have ordered boards and parts to build the replacements. Thanks to davidsrsb and also alumasqrl whose personal blog page led me to this site.