Pioneer SX 780 upgrade to the STK 0050 module II. Is it worth it?

[@mistermac56]

Nice work on a great receiver. The new discrete modules are a godsend as a replacement for the STK 0050 Darlington modules. They are reasonably priced and the build quality of them is excellent.

[@VintageAudioFever]

Yes they are!

[@Craig_Spurlock]

A buddy bought a very clean SX-780 on Ebay, and it had a defective STK0050 that had already been changed once. I convinced him we should go with the discreet modules, and once I got them installed, they worked perfectly. After adjustments, I measured about 52 clean watts per channel into 8 ohms. The modules sound great too!

[@VintageAudioFever]

nice!!!

[@Cass48]

I just had this done to my 780. It sounds great.

[@craigm.9070]

Excellent work! I've seen several of these STK transplant kits installed now; they seem very well made, durable, and serviceable. Another great, classic receiver prepped for a long run, your customer is most certainly happy with the results. Thank you for your time

[@VintageAudioFever]

Great to hear!

[@brianchisnell1548]

Wow Joe. This was fun! I puchased my 780 in 1980. After 6 or 8 years, the power on relay failed. A local tech replaced it . Still going strong 36 years after that. My rig is this receiver, HPM-100s, PL-530, CTF-650. Part time, Man cave use. I was 22 when I bought it. I subbed!!

[@Ezzell_]

Great video. I would like to see a video on your light bulb load box. Could you do a video on it?

[@Fanan67]

Hi, very nice work. One suggestion. Make a lock for your spinning base. She spins very easy witch is good, but when you are making measures or soldering it should be lock and steady. Because if loose you can make a short or a bad join. Thank you for your videos.

[@VintageAudioFever]

hey!!! yes I agree it does get away from me sometimes, I unusually wedge something to stop the spinning when I need to, other than that, I find this table very useful, especially when I am all set it for testing the unit, I can access the front/back but rotating the table without disturbing any of my probs....

[@Fanan67]

@@VintageAudioFever I have one also, they are a must have. I lock mine when I need to, because I already had the probe hitting a wrong place and got sparks and smoke.

[@victorinborsciov6817]

I used to "simulate" STKs with success using discrete components back in 1990. First off, carefully break it, then using a metallurgical microscope to identify components, then make a copy of the internal pcb pattern. Used to love the way internal transistors looked like. Years later did the same thing trying to replace STRs using discrete components but to no avail.

[@VintageAudioFever]

interesting!!!

[@TurntableGuy]

Good job. The aftermarket STK0050s are actually not bad and seem to work well without blowing up, but it's nice to have an alternative.

[@marka1986]

The quality is variable. I did a repair and went through 4 of them in 6 months. Ordered some more from a different place and no problem since.

[@acoustic61]

@@marka1986 Where did you get the good ones?

[@kennethiman2691]

If he wants a forever receiver, I would have done a total recap. They are decades over their lifespan. Love those STK replacements.

[@VintageAudioFever]

Hey Kenneth Capacitors statement is fair enough!! he will have no issues with those caps on this unit for many years to come but again, it's what the owner wanted....I totally respect that!!

[@bulgoczacybulgotnik]

Also put bigger caps in power supply 10000 to 15000uF would B fine

[@danielknepper6884]

Yeah until you blow your bridge rectifier​@@bulgoczacybulgotnik

[@deweydodo6691]

Now I miss my lights on the front face. Think I am down to one bulb on the right side . I bought my sx780 new and its never been serviced. It plays reasonably well yet.

[@elsaarmstrong-zp6ng]

Best audio amp I have ever heard was a pair of Leak TL50 tube amps. Fronted by point plus stereo pre amps. KT88 tubes/valves give soft clipping on even harmonics distortion. Gives out presence like a live music event! Of course you need decent sized speakers like Tannoy Westminster’s which can shift air! Many guitar players like even harmonics distortion i.e. Fender , Gibsons etc!

[@g.fortin3228]

Nice job Joe !! If i find one of these ailing but clean,and can pick it up cheap, it's nice to know this is a worthy repair.

[@VintageAudioFever]

Right on

[@n.b.p.davenport7066]

I have a technique's I believe early 80s works good just needs cleaning for the tuner and volume control

[@davescbradiorepair8195]

Yes it is definately worth the change i always keep 50 on hand.

[@alexzildjian]

YOUR NEW SUSCRIBER 😃 love vintage gear Hi from Baja California MÉXICO 🇲🇽😊

[@VintageAudioFever]

Thanks for the sub!

[@alexzildjian]

@@VintageAudioFever thanks 🙌😊

[@biogons14]

Very interesting video. But I have a question: Shouldn't the offset voltage be readjusted after bias? The offset voltage at the speaker output is affected by the imbalance resulting from the voltage drop across resistors R263 and R265 of 0.22 Ohms after adjusting the bias in the STK0050; isn't that so? Looking at the schematic, the offset compensation system with transistor Q5 seems very ingenious. My Marantz SR4000 has an STK3062 as Pre-Amp driver and has no offset adjustment, and I don't know how to implement it, because I have a channel with -360mV!

[@rubenromero2053]

Hi Joe. I from Buenos Aires, Argentina. Your video is excelent. where could buy these components? (replacement STK 0050). Regards

[@rajoconnor]

Where did you get those meter clips? I need some of those! Also, I’ve used similar stk replacement modules with fantastic results in a sx-680 as well.

[@piotrfi8004]

When Pioneer SX-750? ❤️

[@bonno666]

I had an Akai PA-W04 amp with similar STK 0050-II, and the paint came off too. It could have been that way from factory. Would these STK replacements work for a STK0070-II. So with the suffix II behind the number. He is selling them without the type 2 suffix

[@VintageAudioFever]

I beleive that these STK modules are for several models, I know the seller will answer better on your question than I could and he does responds to questions...

[@Silverface1987]

Can you tell us where these power pack came from. What person or company made them.

[@VintageAudioFever]

You can get them on ebay...look up stk-0050 module 2

[@Luke-12V]

good evening, I really like watching your videos, I really appreciate it, could you please tell me how to easily calculate the power of the amplifier According to RMS, as you showed in the video, 21rms is equal to 51 watts, or something like that, thank you very much for any explanation, All the best

[@VintageAudioFever]

Hi Luke...thank you for watching my videos. The watts per channel are measured RMS X RMS and you decide that number by the ohm you used...so let's say 21 rms would be... 21x21 / ohm resistance...

[@Luke-12V]

@@VintageAudioFever thank you very much

[@DaveofAllTrades75]

Hey joe could you provide a link or name of seller you got the discrete replacements from? I have found some on various places on eBay but they’re the ones you have to build yourself and I would rather get a set that are already made and done professionally like the ones in your video for my pioneer 780. If you could let me know I would appreciate it

[@VintageAudioFever]

my buddy Tim is the guy that bought those STK modules from ebay, I think. I will make sure he see's your comment and hopefully he will get back to you with your question.

[@darylsans]

@@VintageAudioFever I am interested in the modules as well.

[@jedhatcher252]

I want one for the 950 if possible?

[@thwickman]

Do you have any info or a link where to get those stk,s?

[@apolinarmartinez5723]

Great video

[@Bias_Prineus]

Hi joe, how you align this stk amps can you advise, cause I have a Hitachi old one that has sentimental value for me 😢

[@VintageAudioFever]

Hi Geo If your talking about the stk...you can't align the powerpack...already set to go once they are replace....

[@brunY741]

Hi. Any video on the LX-690 Pioneer?. Mine lights up but no click/relay. I changed the stk0039 with no result. Humm....

[@VintageAudioFever]

affraid not a audio ive worked on as of yet.... why did you change the STK's we're they short? and your saying it didn't correct it'self after you change STK?

[@brunY741]

@@VintageAudioFever hi. Thanks for coming back. No I tried to change the stk because I had a couple of it. With poor diagnose method! Shame on me.

[@terencekaye9948]

Is there a schematic for those modules?

[@John-N-541-ym7dx]

Have a SX 780 that eventually will need the STK transplant done, but not until my SX 980 goes down and cannot be brought back to life.

[@sumonvumik8842]

best repair video :)

[@albertoortizsanchez7229]

40:27 Excelente reparación, poseo un Pionner STK, 780. Los STK fallaron. Por favor indíqueme en dónde puedo adquirirlos y seguir disfrutando del excelente sondio GRACIAS. COLOMBIA.

[@VintageAudioFever]

You need the stk0050 module 2

[@media3JBL]

Now you have to ask yourself - Is there anything left on FM radio worth listening to?

[@andershammer9307]

I don't think you can get good stk packs anymore. I have a nice sx-780 also and it is working.

[@VintageAudioFever]

Hi ....you can still get the stk-0050 online, yes...and they work. Just be carefull who you buy them from, do research and read reviews. Etc

[@stevenjosephs9]

What State are you in ( United States ) ?

[@billpeirce7]

Where can I buy these modules?

[@VintageAudioFever]

@VintageAudioFever • 0 seconds ago the customer bought them on ebay , type in STK-0050 module II

[@RalphRacc00N]

I believe those are original power packs, The paint falling off is most likely age. Now if someone would remake the FM integrated circuits.

[@VintageAudioFever]

Hi Ralph...the reason I say they may not be original STK is simply the paint rubbing off.. I was suppose to compare with one that I believe is original but I miss to show it on this video, regardless if they were or not, the customer find them working nicely on this receiver before changing them to the new modules...

[@videocast3655]

@@VintageAudioFever I am a one owner of a 780 and replaced the original packs on it several years ago. They are clearly marked Sanyo on the face. all the replacements I bought just say darlington or whatever on them. I guess there may be some knock offs out there with sanyo on them, but I doubt if they are real this far down the road

[@markmurray5619]

The new STK modules look just like the modules xraytonyb designed.

[@VintageAudioFever]

I seen xraytonyb video on these STK, I didn't know he designed them, I thought he had bought the disassembled kit and he put it all together...I could be wrong tho... xraytony is a great channel for sure!!

[@videocast3655]

correct. xraytonyb credits the designer in his video@@VintageAudioFever

[@fedinkov]

🤘

[@ON5ALE-Alessio]

Pioneer is known to make their stuff to last decades

[@lusitaniafilms]

Hello Joe. What do you know? I am also Joe, and also a Teck. Now when someone woulsay Hey Joe what do you know. I would respond. " how would you like Bullseye on your Dome" :)

[@VintageAudioFever]

Hey Joe...welcome to my channel

[@alexmodel5005]

Without increasing the supply voltage it is not going to make a difference. You should stick to nails and a hammer!

[@VintageAudioFever]

Not sure if I understand your comment!?

[@preston963]

Who wants to know how many thousands of those crap Sanyo STK's in many different products I replaced because yeah they didn't like summer in OZ, Fuse go bye bye very quickly.

[@len9518]

Nice, but you talk too much. You could have easily cut thiis down to 20 minutes, 25 at most.

[@AN-ce1nd]

I had one brand new in 1980. I also had a Marantz 2216B. Guess which one I kept? The Marantz, pioneer is absolutely pure junk.

[@VintageAudioFever]

ok well I am glad you like your marantz..