Music, and a linear power supply (LPS), have been always a good match. The main problems of an LPS is extremely inflated pricing and no data.
Using a transformer will not automatically give you a better PSU. Worst is that too many manufacturers include no testing... no data that can help you choose the right one for you. Allo intend to change that!
First, they started with the transformer. There are many types of transformers, some are worse than others (noise coupling, electromagnetic interference). Allo chose one of the best transformers for noise and emi, r-core.
The transformer has dual outputs (galvanically isolated) of 5.2V 3A and 5.2V at 1.2A so you can power multiple devices (Raspberry Pi 4 or 3 + a DAC, Katana, BOSS or others) and also use independent (of course, since they are isolated) filtering on each rail. First, a capacitance bank (massive) to reduce the 50/60Hz noise, then an active filter, followed by an LDO to keep voltage stable. Since LDOs have poor transient and impedance, Allo used a last active filter (with good transient) and then capacitors of more than 15.000uF but most importantly, supercapacitors on the output. Final power comes in fact from super caps... transients and impedance of the LPS are...very good!
Lastly, the Shanti includes an AC line filter and the AC side is earthed to the casing. A few words on what they achieved. Measuring noise (in a real-world scenario) they saw about 80nV (0.08uV of noise from 0-20Khz) at the floor of their AP machine. This is comparable to batteries from their internal testing.
Shanti is not only shining because of the ultra-low differential noise and common mode noise but also because of the incredible low impedance / deep reservoir of electrons at the output of the PSU.
Shanti Noise Graphs
- Dual output (galvanically isolated) 5.2V 3A and 5.2V at 1.2A
- Power multiple devices (Raspberry Pi 4 or 3 + a DAC, Katana, BOSS or other)
- Independent filtering on each rail
- Supercapacitors on the output
- Incredible low impedance / deep reservoir of electrons at the output of the PSU
- Includes multiple adaptors (see below)
- 1x Shanti PSU
- 1x UK IEC Plug lead
- 1x DC 5.5x2.1mm Input to 5.5x2.5mm Output
- 1x DC 5.5x2.1mm Input to 4.0x1.7mm Output
- 1x DC 5.5x2.1mm Input to 4.8x1.7mm Output
- 1x DC 5.5x2.1mm Input to 3.5x1.35mm Output
- 1x DC 5.5x2.1mm Input to Micro-USB Output (cable)
- 1x DC 5.5x2.1mm Input to USB Type-C Output (cable)