Studio Reference Amplifier

[Luke]

Apex psu 10 - trial

Nice, if your making pcbs, I would be interested in some.

 

[Arif Budiyanto]

This is my SR200 with Soft Start, but i plan to move this soft start. It is located too close to Solen input capacitor, it affects some noises into right channel amplifier block.

 

[ahmadfay]

I am having trouble finding BC560 transistor, can I replace it with another type, for example BC557? thanks

 

[wintermute]

I'm not familiar with the circuit, but a bc557 is similar in a lot of specs to the bc560. However the bc560 is a low noise part.

you might try futurlec BC560 - BC560 PNP Low Noise Transistor It's a long time since I ordered off them but delivery time to Aus was about 2 weeks from memory.

Tony.

 

[ahmadfay]

thanks for the info.
I mean, is there any equation of this type that might get my place?

 

[apexaudio]

This is my SR200 with Soft Start, but i plan to move this soft start. It is located too close to Solen input capacitor, it affects some noises into right channel amplifier block.

Nice work

 

[apexaudio]

I am having trouble finding BC560 transistor, can I replace it with another type, for example BC557? thanks

BC557 can be use instead BC560.

 

[ahmadfay]

BC557 can be use instead BC560.

thanks for the response ...
regards

 

[shravanth]

hello sir
what is the
THD,
frequency response,
damping factor of SR200

 

[ahmadfay]

I have completed the SR 200 project, the result is quite satisfactory in terms of sound quality, but there is a little problem on the final transistor excessive heat, bias from base to base in the set at 1.9 volts. does anyone have a solution to this problem?
thanks

 

[Junie]

which version of PCB you use? Post some pics.

 

[ahmadfay]

with this one...

 

[mj777]

@ahmadfay,those are nonpolar capacitor

 

[ahmadfay]

alright.
though with great difficulty I have got it. but I still can not set up the bias voltage, so that the final transistor gets hot, but I have a bias vr turn to the right and left. is there someone who can help me?
thanks

 

[Arif Budiyanto]

Hi Mas Ahmadfay...
As a common I set bias by measure v across R 0.33 Ohm. Set bias low first, let it run for couple days. When your amp survive then raise the the bias...Please always check the HS temperature...

 

[ahmadfay]

ok Mas Arif, tak coba-e
this is brilliant idea,
thanks

 

[marestiani]

I just made ​​SR50 and the sound is great, but the BF's transistor are quite hot when turned on for 5 minutes, is this normal or is there something wrong with the circuit that I created, help me please newbie here

An externally hosted image should be here but it was not working when we last tested it.

 

[apexaudio]

I just made ​​SR50 and the sound is great, but the BF's transistor are quite hot when turned on for 5 minutes, is this normal or is there something wrong with the circuit that I created, help me please newbie here

An externally hosted image should be here but it was not working when we last tested it.

Nice work, BF's must be hot, what is your rail voltage and what pcb design you use?
Regards

 

[marestiani]

Nice work, BF's must be hot, what is your rail voltage and what pcb design you use?
Regards

Thank you sir apex, i use 35Vdc rail voltage with 10A fake transformer the final transistor used A1943 - C5200 Grade II (only these sell in local store nearest my home) but the temperature not to hot and one more question if i use TL071 what do i have to change to the board? so hard find LF411 in here only got 5pcs last week, i used pcb design in attachment, thanks for sharing a good knowledge n schematic, this is my first build next i will build B500
Regard

 

[apexaudio]

Thank you sir apex, i use 35Vdc rail voltage with 10A fake transformer the final transistor used A1943 - C5200 Grade II (only these sell in local store nearest my home) but the temperature not to hot and one more question if i use TL071 what do i have to change to the board? so hard find LF411 in here only got 5pcs last week, i used pcb design in attachment, thanks for sharing a good knowledge n schematic, this is my first build next i will build B500
Regard

You can use TL071 instead LF411 without any changes.
Regards