Studio Reference Amplifier

[44250]

this supposed to be a HiFi amplifier, I wouldn't put limiter on the input. limiters are more PA thing...

 

[Yuriy64]

Hello friends. Tell me please the minimum and maximum voltage PSU for the amplifier APEX SR100.

 

[saminnografix]

this supposed to be a HiFi amplifier, I wouldn't put limiter on the input. limiters are more PA thing...

i have revisited the forum today i suppose to attach my SR300 layout for perusal in post#2660 but was not there so i am uploading it now and i added my SR250 too in case some can give inputs too......so i can correct it before making the PCB.🙂

regards
sam

 

[44250]

at sr300,I would only switch places of + and - connectors with fuses,so when current comes from PSU than it flows through fuse than to first large capacitor,to second and than to output transistors. that way you have constant flow of current in one direction instead forward - backward to and from those big capacitors. I like all the rest you did there!

 

[Vrystaat]

Stereo protection

Hallo guy's,
Can somebody plse post a stereo DC protection circuit from apex with the PCB layout.
Thanks a lot !🙂

 

[saminnografix]

at sr300,I would only switch places of + and - connectors with fuses,so when current comes from PSU than it flows through fuse than to first large capacitor,to second and than to output transistors. that way you have constant flow of current in one direction instead forward - backward to and from those big capacitors. I like all the rest you did there!

Copy that, thanks,
regards,
sam

 

[apexaudio]

SR800

 

[Yuriy64]

Apexaudio. Tell me please the minimum and maximum voltage PSU for the amplifier APEX SR100.
What kind of power supply do you recommend for this amplifier?

 

[apexaudio]

Apexaudio. Tell me please the minimum and maximum voltage PSU for the amplifier APEX SR100.
What kind of power supply do you recommend for this amplifier?

From +/-35V to +/-55V 300VA for stereo.

 

[44250]

SR800

nice one, really!

 

[saminnografix]

nice one, really!

it's not just amp it's APEX's SR series...
i have made PSU 75 before, but labeled it with PSU85 for having 63-0-63vAC that might be good for SR800 here are some pix,

i have some question for the attached soft start in case of brown out will it reset? second what power switch do i need is it momentary switch or latching switch? i am powering up a 2.5-3.0 kVA traffo,.... i like this softstart so no high voltage on front panel.

thanks
regards
SAM

 

[Dennis T]

guys, anyone with the PCB of sr300 in PDF format email Dennis. makununika@gmail.com or post

 

[44250]

#2671
I have not seen this post before, and now I really have not understand the question... I would be glad to help!

 

[thimios]

it's not just amp it's APEX's SR series...
i have made PSU 75 before, but labeled it with PSU85 for having 63-0-63vAC that might be good for SR800 here are some pix,

i have some question for the attached soft start in case of brown out will it reset? second what power switch do i need is it momentary switch or latching switch? i am powering up a 2.5-3.0 kVA traffo,.... i like this softstart so no high voltage on front panel.

thanks
regards
SAM

This circuit isn't a soft start circuit!
It is just a push on push off circuit and uses main voltage for 4011 i. c. Use switch button suitable for main voltage only!!!
These are <<alwayes live circuits>>.

 

[apexaudio]

This circuit isn't a soft start circuit!
It is just a push on push off circuit and uses main voltage for 4011 i. c. Use switch button suitable for main voltage only!!!
These are <<alwayes live circuits>>.

Yes, there is no high current but there is high voltage reference to ground on front panel on/off button.

 

[anoopkrajan]

Hi,
Any equivalents for LF411 and BF420,421
Thanks and regards.
Anoop

 

[robydream]

Regulated PSU PCB V1.0

Here is files for Regulated APEX PSU-5 V1.0.pcb in pdf is mirrored ready for toner transfer so when you are making PCB please make sure that you need to mirror it if you plat to use it for photodevelopment of pcb.

 

[Yuriy64]

Hi, Mr. Mile!

Tell me please some information about the APEX SR300 amplifier:
Min and Max voltage PSU - ??...?? V
recomended voltage PSU - ?? V
recomended BIAS current - ?? mA
What is the power of the amplifier with the recommended voltage PSU - ?? W

Thank you in advance.

 

[Dennis T]

thank you for the psu_5 Schematics

 

[duyminh1984a]

sr200 version by hand