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Boss 2 Player (Aluminum Case)
#1
Mine arrived two days ago. I ordered it with the Moode SD, and the unit booted right up and installed, scanned to create the library database without a problem, and played without a problem. Moode version is 7.01, but obviously has the Boss2 additions needed to work. It sounds like the 7.1 release will be a more complete implementation (chip options?).

One issue, just in case someone else uses balanced AC. I have run a seperate 240VAC circuit from my main panel to my system location with a 240 outlet. I connect a box with two stepdown transformers to this box. The secondaries of those transsformers are connected to quad 120VAC outlets that power my system. Safety ground is continuous throughout.
I've done this for years to good (quiet) effect. There is one caveat -- what is normally the neutral on single-phase 120VAC is now 60VAC antiphase to the hot side. This means the neutral within anything powered by this system is not tied to saftey ground back at the panel. The risk is that poorly designed equipment could short the two leading to instant smoke. I build a lot of my own equipment, and always use switches that break both legs, and always fuse both legs.

I have used an Allo Shanti in this system for a good while with great success. I ordered a Nirvana with the Boss2, and noticed a slight somewhat variable fuzzy noise in my speakers  perhaps 120hz with some higher harmonics. Barely audible at the listening position with my old ears. So I started switching units around and discovered that the noise was not there when I powered the Nirvana from a conventional 120VAC single-phase outlet. It is also dead quiet with the Shanti on balanced power. I do not consider this a flaw in the Nirvana as plugging into the differential 120VAC is well out of its design spec.

How does it sound?  Good. I won't elaborate since I believe I should listen for several weeks and optimize the settings (maybe with 7.1) to provide a knowledgeable impression.
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#2
Just a data point. I've been listening to Boss 2 (Acrylic case, Pi-4B, single power feed, default chip options) for the past several weeks and to my ears it's clean, smooth, fatigue-free and there are no start/stop audio glitches whatsoever :-)
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#3
I can find the datasheet for the DAC chip used in the BOSS 2. The chip looks great. However, I can't find any formal statement of the resulting BOSS 2 specs on the Allo site. The downloadable BOSS 2 Manual is, umm, uninformative.

https://github.com/raspberrypi/firmware/...lay/README  says the overlay has no parameters, which implies no hardware volume control. Is this so?

Code:
Name:   allo-boss2-dac-audio
Info:   Configures the Allo Boss2 DAC audio card
Load:   dtoverlay=allo-boss2-dac-audio
Params: <None>

Regards,
Kent
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#4
Hardware mixer is not an overlay param but rather part of the set of ALSA controls exposed by the driver. Below showing two hardware mixers "Master" for PCM and "Digital" for DoP. The other controls are chip options.

Code:
pi@rp2:~ $ amixer scontrols
Simple mixer control 'Master',0
Simple mixer control 'PCM De-emphasis Filter',0
Simple mixer control 'PCM Filter Speed',0
Simple mixer control 'PCM High-pass Filter',0
Simple mixer control 'PCM Nonoversample Emulate',0
Simple mixer control 'PCM Phase Compensation',0
Simple mixer control 'Digital',0
Simple mixer control 'HV_Enable',0
pi@rp2:~ $

Specs
http://moodeaudio.org/forum/showthread.php?tid=3094

FFT plots
https://www.allo.com/sparky/boss2-player.html

I think Allo sent a sample to Amir at AudioScienceReview so expect a more in depth set of plots and data when that review is published.
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#5
Cool, thanks.

Regards,
Kent
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#6
I just thought of one question. Since the Boss 2 player offers volume control with the (very small) display and remote, is there any reason to set the Moode volume control, which I have always used happily, to 100 and use the Boss 2, or the opposite, for that matter?

Thanks
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#7
Ideally you would want the volume changes made via the joystick or remote to be reflected in the moOde knob. I can prolly modify their OLED driver to do this in > 7.1.0 release.
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#8
That would be nice, but I can deal with it as it is should your time demands push it off to the side.
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#9
Have you had possibility to compare with USBridge sound?
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#10
I don't have a USBridge, so no comparison. I'm not sure it would be valid unless the USBridge was connected to a Boss2 DAC.
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