DIY STK-0050 module.

[mastersur]

Dear compatriot:
I searched a lot, there's enough info on the web but I have not compiled almost nothing. I found a schematic and someone who manufacture a replacement very well done, attached photo, but I did not find the drawings of the PCB.
Really disappointed me a little and leave the subject, but I still interested.
If anyone has more info is welcome and refloats the post.
Regards!

 

[stocktrader200]

I have an old sx 780. one channel blown STK0050II on other channel.
you can replace the STK with an IRFP240 and IRFP9240 with 6.8v bias zener
they are much better and an 82pf cap replaces the 10pf stability cap
sound is much better. The amp circuit is very close the the Ultimate amp circuits in other threads here.
I am thinking of replacing the TA7136p with a 6922 based tube preamp. that should make it competitive with $2500 equipment.

 

[AndresEsteban]

I have an old sx 780. one channel blown STK0050II on other channel.
you can replace the STK with an IRFP240 and IRFP9240 with 6.8v bias zener
they are much better and an 82pf cap replaces the 10pf stability cap
sound is much better. The amp circuit is very close the the Ultimate amp circuits in other threads here.
I am thinking of replacing the TA7136p with a 6922 based tube preamp. that should make it competitive with $2500 equipment.

Thanks for the info, could you be so kind as to share with us an schematic of how to connect the two IRFP transistors and the zener diode in order to replace the STK0050 module? Regards, Andy

 

[dcairns]

I know this is an old-ish thread, but I did run across this:
STK-0050 Module W/ Power to operate sets up to 100 Watts (Open Source) | eBay

Link to seller, since listing links expire
bobandelainepike on eBay

 

[prairiemystic]

I have STK datasheets and a pic of one I took apart.
The old ones in the 1980's did sound quite good, but bonding wires always breaking off.

 

[JMFahey]

Excellent idea, very useful.

 

[rsavas]

My contribution to the DIY world, see Audiokarma thread for more info.
STK-0050 replacement for SX-780 and others | Audiokarma Home Audio Stereo Discussion Forums
bobandelainepike on eBay are offering Al plates and pcbs for sale.

 

[xavirom]

Hello everyone. I am looking for some diagram, preferably tested, of a discrete version of the STK0050II, in my country (Argentina) only fakes are obtained. Any suggestion is welcome. Thank you all.
Its for AKAI AM U04

 

[merlynski]

My contribution to the DIY world, see Audiokarma thread for more info.
STK-0050 replacement for SX-780 and others | Audiokarma Home Audio Stereo Discussion Forums
bobandelainepike on eBay are offering Al plates and pcbs for sale.

I have personally used this option, and it works like a charm!

 

[Vinibob]

DIY STK

They sure do! Thanks to Bob & friends for engineering this. I can appreciate what went into this. Well done.