Fake STK3152/STK3102

[alainparis]

Hello, I was just planned to order a STK3102 in ebay...and now I really hesitate . The ampli I have is a marantz PM-80 and I am investigating but more and more think on a failure on this STK3102IV.
However, when I saw the soldering on the picture, cannot do this on so small. So is it possible to order it with components soldering and not only the PCB? Alternatively how to find a real STK3102IV? ( As my case is similar to pioux, guess french will get a lazzy reputation...)

 

[kozard]

If you order the PCB from JLCPCB or PCBWAY you can also order a solder stencil with the PCB. Then there are tutorials video online about screen printing the paste with the stencil. It might be an interesting new challenge to learn perhaps? Or perhaps not for everyone? JLCPCB can do the assembly but it is a bit of a learning curve in KiCad to do the BOM and centroid file if you do not have regular need to learn such skills.

 

[alainparis]

It would be a challenge. Few month ago, just did a very simple PCB using easyEDA and it was a long time I did a PCB! KiCad and easyeda are similar?

However the PM80 belongs to a friend and I should give it back...so will not be able to enjoy it ...

 

[kozard]

I have not tried EasyEDA. KiCad is pretty easy once you get over the initial learning curve like any CAD program. But I think learning SMT stencil and reflow is easier than learning all the details of getting SMT assembled at JLCPCB with KiCad.

 

[davidsrsb]

I have deliberately avoided using the tiniest SMD parts, to make hand soldering using reeled solder practical

 

[Lars71dk]

Hej Kosmic,

Do you have more PCB's for sale? I am in Denmark, and would like to build one.

Regards,
Lars

 

[Kosmic]

Hej Kosmic,

Do you have more PCB's for sale? I am in Denmark, and would like to build one.

Regards,
Lars

Hej Lars

Ja - jeg har stadig 3 print.

or

Yes - I still have 3 PCB

 

[goaty]

Has anyone one PCB for sale to Germany ?
Thanks, Thomas

 

[Lars71dk]

David, regarding cooling, and if you are updating the gerber files, how about making it double sided with at lot of through-holes? and how about two 3 mm holes to enable an aluminum sheet to be tightly boltet to the pcb?

Thanks, LArs

 

[kozard]

Why not build the aluminum PCB version? JLCPCB charges $2 for quantity 5 of such a small aluminum PCB. Airmail shipping is cheap.

 

[Lars71dk]

Why not build the aluminum PCB version? JLCPCB charges $2 for quantity 5 of such a small aluminum PCB. Airmail shipping is cheap.

Because I didn't know about that product, but now I can see it is really interesting for this application!

 

[kozard]

Did you find the link to that thread with the gerbers?

https://www.diyaudio.com/community/threads/stk3152-stk3102-clone-for-aluminium-back-pcb.380947/

 

[Lars71dk]

Did you find the link to that thread with the gerbers?

https://www.diyaudio.com/community/threads/stk3152-stk3102-clone-for-aluminium-back-pcb.380947/

Yes I did! looks like the way to go! have you ordered?

 

[kozard]

No, I was looking at the aluminum boards for another purpose and when I saw this thread I thought it might help and so I suggested it. I have a couple of different amplifiers with different STK modules. However my main amplifier at this time is a Krell clone.

 

[Lars71dk]

Ok, I made this module for a Sony 530ES. Got it up fine. In idle all looking good, stable, bias adjusted. Measured a temperature of 45 degC, no worries.

Next step, apply some input - failed, heavy oscillation of the output stages! Both with and without a load.

Will check the feedback path.. but.. any suggestions?

 

[Lars71dk]

Ok, I made this module for a Sony 530ES. Got it up fine. In idle all looking good, stable, bias adjusted. Measured a temperature of 45 degC, no worries.

Next step, apply some input - failed, heavy oscillation of the output stages! Both with and without a load.

Just to follow up - after a redesign of mainly the feedback loop (which had mismatched capacitances causing the oscillations), the Sony now plays beautifully.

 

[davidsrsb]

We have no information about the transistor die types used in the original module, so it is always likely that the clone module will need some compensation tweaking.
Many of these amplifiers were chasing headline distortion figures at the expense of stability margins

 

[Lars71dk]

We have no information about the transistor die types used in the original module, so it is always likely that the clone module will need some compensation tweaking.
Many of these amplifiers were chasing headline distortion figures at the expense of stability margins

Right, and I think everyone is likely to run into this problem. In a test setup similiar to the original application note, I get oscillations as well.

 

[davidsrsb]

Changing this module will usually go along with changing the output transistors, even more stability concerns

 

[TurvenuijaFIN]

Does this renewed module directly replace the marantz pm-84 mk2 original stk3122III?

I have near mint condition pm-84 mk2 but right channel of stk is blown. I think to go with nte1339 but its voltage endurance is too low. Marantz voltage supply is +-65V. and it has mosfet outputs if it does matter. (J115/K405)