Studio Reference Amplifier

hi to everyone,what is advantage of this buffer? for good quality sound like dj what i need before amp? i have mixer and crossover.please anyone tell me what i do for good quality.thank you.

Use this preamp.
 

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you forgot to add apex logo on this pcb.apex logo must be on pcb which is design by apex audio.

I always try to put some text on pcb design. When you make your own pcb's it's the simplest way to control proper side of film. A few times I flipped film in the wrong way, so I had to etch again 🙁.
You can see text on PP8, but on PP12 I didn't have enough room to put visible text. I could use very small letters, but there's no reason if you can't read text.
I don't use Apex logo, I leave it to Mr. Mile. I use different font, so you know it's Apex clone.
 
hi apex sir,i have 225va transformer and 14700 (10000+4700)uf per rail with 6 ampere diode.dc voltage +-55 and +-24(for sr preamp) and 5vdc for mp3 palyer.is 14700uf per rail is enough for sr150 stereo?thanks.
 

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my SR150 works with 2x35Vac transformer,and that is a voltage that you connect to AC/AC on left/bottom side of pcb. AC/AC are connectors to supply protection circuite. you have a schematics of protection circuite in a post where i posted that pcb,instead 2N5401 better use BC516 (reversed pinout!!!),there is also an explanation how to chose resistor 560r,depending on your relay coil resistance.

protection circuite is based on APEX simple protection,only i changed voltage direction and with it polarity of diodes and capacitors and type of transistors (npn to pnp).

there is also clip-indication on this pcb.

here are all those schematics used on pcb again:
 

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