Excellent result on the ripple scope shot George! I'm thinking perhaps the ripple peaks aren't equal because there's a slight mis-match in voltage between the two phases of your secondary. You are using the CT as the ripple frequency is 100Hz. So with just 2mV p-p ripple at the regs, even 60dB regulator PSRR will only give 2uV p-p at the output, well below the inherent noise of their bandgap reference. Whereas without the inductors the raw ripple at the output would almost certainly rise above the regulator noise floor. 👍
I rewound the burned primary. Then removed the secondary too and wound five secondaries. Two symmetric (bifilar) and one single.
Everything with 0.4mm wire.
One symmetric secondary will feed Abrax triple PSU
Attachments
Hi guys, just to show you my PCM58 DAC. Thanks to Richard for his kind and continuous support.
Gaetano.
Gaetano.
Alexopth1512 went to the trouble to set-up a Raspberry Pi.4 for me (linux+Volumio+Tidal)
This small thing allows me to listen from internet sources (web radio, You Tube, paid streaming) plus music from my local files (USB hard drives).
It has the great advantage that it's USB output signal is electrically clear. No groundloop noise issues that have haunted me with PCs, thus no need for USB or I2S isolators. It is also fanless.
I can control Tidal source and music files from my smartphone, so it turns out I finally don't need the 10inch LCD display.
Tidal also provides optional resampling.
Raspberry USB out to Amanero Combo 768, to I2S/SPDIF/optical switch to quad PCM58 DAC to Dark LED I/V.
All powered through the triple PSU.
The sound is BIG, clear and very satisfying to my ears. Kudos to Abrax one more time
Dizzie Gillespie's "Afro" (1954) now playing.
Wow!!!
George
This small thing allows me to listen from internet sources (web radio, You Tube, paid streaming) plus music from my local files (USB hard drives).
It has the great advantage that it's USB output signal is electrically clear. No groundloop noise issues that have haunted me with PCs, thus no need for USB or I2S isolators. It is also fanless.
I can control Tidal source and music files from my smartphone, so it turns out I finally don't need the 10inch LCD display.
Tidal also provides optional resampling.
Raspberry USB out to Amanero Combo 768, to I2S/SPDIF/optical switch to quad PCM58 DAC to Dark LED I/V.
All powered through the triple PSU.
The sound is BIG, clear and very satisfying to my ears. Kudos to Abrax one more time
Dizzie Gillespie's "Afro" (1954) now playing.
Wow!!!
George
