I wanted a bit more power for my Koss PortaPro.
Sound is more bassy, but midrange and hights are bit muddled, so I’ll be upgrading it with better caps and Opamp LM4562NA. LM4562 – LM4562 Dual High Performance, High Fidelity Audio Operational Amplifier Datasheet in PDF which will be another £3 I guess.
All cost me about £15 on parts including enclosure. I bought ready made PCB. Also I would like to get some decent engraving on the top of enclosure.
PCB is pretty tiny.
So there’s quite empty space in enclosure, but I can’t be arsed more.
9v Battery is taped to other side enclosure lid.
LED is beaming to gap when power on.
Not my best work, but it will sound satisfying with little bit of upgrades.
Front side. Right Jack is OUT, Middle ON-OFF/ 47K volume pot, Left Jack IN.
Engraving on the top make it look wicked!
Job done, merry Xmas!
UPDATE: Now more like £20 CMOY
I have upgraded my little CMOY:
– better resistors in power section
– Wima capacitors 0.1 uF instead of 15pF noname
– Opamp LM4562NA instead of LF353N (datasheet in PDF)
– new cable Van Damme pro grade classic XKE silver plated OFC with Neutrik angled Jack 3.5mm
Much much better sound now.