Studio Reference Amplifier

[Arif Budiyanto]

Maximum supply for SR200 is +/-75V
Regards

Ok, thank you so much for your advice...If I supply this amp up to lets say +/-70V, will it give significant sound improvement? Now I feed this amp with +/- 59,5 volt, and I like the sound very much.
Best regards,
Arif

 

[naf]

SR200 from Indonesian forum

Congrats, nice build my friend!

 

[Arif Budiyanto]

Thank you Naf...

 

[Arif Budiyanto]

Another one using blue Fullcap capacitors...

 

[Arif Budiyanto]

I hope this one is fine

 

[apexaudio]

Ok, thank you so much for your advice...If I supply this amp up to lets say +/-70V, will it give significant sound improvement? Now I feed this amp with +/- 59,5 volt, and I like the sound very much.
Best regards,
Arif

Suply this amp up to +/-70V will only increase power,
Regards

 

[Arif Budiyanto]

Suply this amp up to +/-70V will only increase power,
Regards

Ok many thanks Mr. Apex
So I will stay around 60Vdc.
Best Regards,
Arif

 

[JOHN BALI]

Thermal Coupled

Hi...
This my PCB design of SR200,
Are all these small TR need to thermally coupled?
I arranged them like that so it easy if it is need to thermally coupled

It is still need to be check again & if it its a bad design I will redesign again...

Regards

 

[Arif Budiyanto]

Dear Apex,
I have 2 pcs of 4,7 uf Jantzen MKP, is it possible to use them instead of 10uf (C1), considering that now I use very low budget 10uf MKP. What is the result? Or should I have to find another 10uf MKP. It's hard to find good 10uf MKP in local suppliers.
I also have 2 pcs 2,2 Bennic's and 2 pcs Solen MKP and I plan to use them instead of 1uf (C4) for the same reason above.
Thank you so much.
Best Regards,
Arif B

 

[apexaudio]

Dear Apex,
I have 2 pcs of 4,7 uf Jantzen MKP, is it possible to use them instead of 10uf (C1), considering that now I use very low budget 10uf MKP. What is the result? Or should I have to find another 10uf MKP. It's hard to find good 10uf MKP in local suppliers.
I also have 2 pcs 2,2 Bennic's and 2 pcs Solen MKP and I plan to use them instead of 1uf (C4) for the same reason above.
Thank you so much.
Best Regards,
Arif B

It's possible to use 4,7uF instead 10uF in audio path, but no need to change 1uF in DC servo circuit.
Regards

 

[Arif Budiyanto]

Dear Apex,
Thank you so much for your fast response..
Are there any sound changes referring to this change by using 4,7 uf instead of 10uf? Because it means that the new one is less than 50% comparing to the previous value.
Many thanks.
Best regards,
Arif

 

[apexaudio]

Dear Apex,
Thank you so much for your fast response..
Are there any sound changes referring to this change by using 4,7 uf instead of 10uf? Because it means that the new one is less than 50% comparing to the previous value.
Many thanks.
Best regards,
Arif

Sound changes is unaudiable
Regards

 

[Arif Budiyanto]

Sound changes is unaudiable
Regards

Ok, I will try it!
Many thanks..
Arif

 

[jprco]

New to this thread and would like to start at square 1 with SR50 but can't get BF420/421. Any suggestions for direct replacement (ZTX457??). See these were dropped in versions of SR100/SR200. Thanks

 

[apexaudio]

New to this thread and would like to start at square 1 with SR50 but can't get BF420/421. Any suggestions for direct replacement (ZTX457??). See these were dropped in versions of SR100/SR200. Thanks

Use BF471/472 or BF871/872 instead BF420/421,
Regards

 

[jprco]

Thanks for the quick reply. Unfortunately, the recommended replacements are even harder to source here ie BF471;s/871's! Can you suggest new alternates or a supplier? Maybe I should skip the SR50 and move to SR100...but I would like to start slowly,

 

[leonatax]

Hi Apex can you help me, how can i make protection on rs200 like on ax20p-ax14p
thank you very much

 

[apexaudio]

Hi Apex can you help me, how can i make protection on rs200 like on ax20p-ax14p
thank you very much

Protection circuit from AX14P can be add on any amp, and on SR200 also.
Regards

 

[apexaudio]

Thanks for the quick reply. Unfortunately, the recommended replacements are even harder to source here ie BF471;s/871's! Can you suggest new alternates or a supplier? Maybe I should skip the SR50 and move to SR100...but I would like to start slowly,

MPSA42/92 can be use, but pins are E-B-C instead E-C-B (BF420/421)

 

[Arif Budiyanto]

Dear Mr. Mile,
I am sorry for giving you this question...
What is the best bias setting for SR200 when I measure across r10Ohm (temporary replacing the fuse)?...I read this bias setting before but I forget the value...
Best regards,
Arif