Allo boss dac 1.2 plus raspberry pi2

[jasonC]

Allo boss dac and raspberry 2b plus free aftermarket psu.
£50 plus 5 pounds for delivery
Will supply a ethnet cable too, 5m
No case so you will need to source one

Allo Boss Dac Hat 1.2.

https://darko.audio/2017/11/allos-59...ious-pi-maker/

https://theartofsound.net/forum/show...e31#post845301

https://www.diyaudio.com/community/t...-7#post5025035


https://community.roonlabs.com/t/all...c-review/20575




We all live in a society obsessed by brand names and the latest gadget. Sometimes with reason sometimes with none.

The RPI has one major problem with audio. The clocks coming from CPU can only output one frequency clock perfect (very close), resulting in major problems with audio files sampled at 44Khz (and multiple).

Too much jitter on i2s clocks.

So we invented theKalibut there is a second way.

Enter the master mode for i2s. Instead of the RPI giving the clock on the line, the DAC itself sends the clocks and RPI sends the data (file to be played). Since we used 2 clocks the problem above disappears.

Ours is not the first master DAC on the market, there are others... read on. Our BOSS DAC is unique, because of the way we have implemented the design.

First we separate the power on 3 channels and filter it: one for the digital side, the second for analog and third for the clocks themselves. Then we take the filtered power and use a second filter (LDOs) to further quiet the noise. Note that we use some of the best LDOs on the market (LT3042 from Linear).

In addition, we use Japanese oscillators from NDK for a very low jitter clock - almost as good as famous Crystek.

Finally, on the analog stage we are using a film capacitor (not ceramic) for a quiet DC to feed the TI IC (ceramic exhibit some piezo distortion, not what you want in analog stage).

Not happy with this, we have added a supercapacitor for an extra kick when analog stage is asking (like deep bass). What we have achieved, in our opinion, is the best analog implementation of the PCM5122 on the market, while at same time correcting the clock problem from RPI.

Yes we live in a society obsessed with the latest gadgets. The BOSS however, is a very solid implementation of the PCM IC that will give you the greatest bang for your buck.

It will sound great no matter what you throw at it - this was our goal and promise to you.

Measured Jitter Compatibility Compatibility: RPI only. Isolator board (at 192Khz). Relay attenuator. PSU: BOSS v1.2 can be powered independently after removing the jumper (see manual) Not Working With: Sparky, Kali *** NEW Features Latest generation ULTRA low phase noise NDK oscillators (SDA series) Dedicated Type C USB connector to feed 5V 3A independently (see manual) Optimized component layout.

New film capacitors on analog stage Features BOSS 1.2 is a Master DAC

Compatible with RPI 2 , RPI 3 and Rpi4

Compatible with OSMC / Max2Play / RuneAudio / Volumio / Moode / PiCorePlayer / PiMusicBox / OpenELEC and others + Roon Ready

Dedicated 384 kHz/32bit high-quality DAC PCM5122 for best sound quality Audio output connectors: 2 x RCA (Left & Right ) & Allo Volt Amp header HAT size
Sampling Frequency ranges from 8 kHz to 384 kHz Ultra-low-noise voltage regulators & LPF for optimal audio performance Integrated EEPROM for automatic configuration (with write-protection)
Automatically switching frequencies according to the input I2S signalsa

Latest generation ULTRA low phase noise NDK oscillators (SDA series)
Dedicated Type C USB connector to feed 5V 3A independently (see manual)
Optimized component layout
New film capacitors on analog stage
input I2S signalsa

20220523_211437 by Jason Croft, on Flickr


20220523_204658 by Jason Croft, on Flickr


20220523_202905 by Jason Croft, on Flickr


[20220523_202915 by Jason Croft, on Flickr

[jasonC]

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