I am new comer for this Forum.
I saw this topic and had same idea and make my own PSU for my DAC & Headphone AMP.
Just made Dual PSU using LM1085/LM317 with compact metal case.
This is my first prototype. I already made two PCB (one for AC EMI filter, other for regulator parts)
I don't own ND-S1, according to this user manual, their adapter is 5V 1A.
My adapter uses 30W transformer 12VAC. I had VR to adjust output voltage to fit my player.
I use this for my Cambridge Audio dacmagic2 DAC (note :it uses AC12V) & HeadAMP from www. hifidiy.net
, also any portable device such are CD discman, MP3 player etc.
LM1085 can give max 3A output where LM317 can only give 1.5A.
If uses 5V output base on 12VAC to DC then I/P to LM1085. It become very hot becasue of high voltage drop. If under 1A continues supply I think it should be acceptable as I am using the metal case as a heatsink.
One of benifit to use discrete is high S/N ratio. Normally regulator IC just gives @70dB (max). If good circuit discrete design it can reach higher than this value. However, PCB size will relative bigger because of increase components, typically design using Transistors & OP-AMP as well as reference IC for combinaton
I prefer compact size[mind is @120(L) x 40(H) x 90(w)] and high flexiable, multiple adjust output so that I choose Regulator IC.
Woo, is it really need such high power (12V 5A ~60W)?? It is possible using LM1085 but need a shunt transistor to share some current as LM1085 Max can only give 3A.
Also, Transformer need at least 80W for maintain output if HD800b always eat such high power.
I am under checking on my latest PCB which has shunt transistors for sharing current, now is under evaluation and wait for custom make transformers.
[複製鏈接]
