Allo Boss2 Review (Stereo Streamer)

[johan]

Thx you Aurel for the data. Most of the power consumption comes from RPIs with just a small percentage coming from SMPS.

 

[AdamG]

Hello everyone,
I measured the consumption at rest of the Boss 2 Acrylic with an RPI3B + and an RPI3A + under Moode 7.2 in 5ghz WiFi:

RPI3B+ + Nirvana 2.85A = 3.7 watts
RPI3B+ + Allo Made in china power supply 3.0A= 2.7 watts
RPI3B+ + IFI power supply 2.5A= 3.7 watts

RPI3A+ + Nirvana 2.85A= 2.1 watts
RPI3A+ + Allo Made in china power supply 3.0A = 1.7 watts
RPI3A+ + IFI power supply 2.5A= 2.0 watts

Welcome Aboard @Aurel71.

 

[Aurel71]

Welcome Aboard @Aurel71.

Thanks you

 

[Bamyasi]

It is interesting how Allo engineers were previously adamant in their choice of RPi3/CM3 for all their designs, with their main argument being that it is more "quiet", i.e., generates less EMI and other forms of out of band noise. You can read numerous comments from them on audiophilestyle.com in response to questions from users about utilizing RPi4, all very negative. Now they have finally used RPi4 in their own design, which demonstrated clearly that RPi4 can exhibit excellent dynamic range / noise levels in audio applications. I found it to be quite ironic.

 

[DeepSpace57]

@johan do you plan to release the balanced variant (XLR) of this little DAC anytime soon?

 

[johan]

Bamyasi , RPI4 has multiple buses . Boss2 works on i2s . To remove hi frequency noise from lines we are using buffers (Schmidt triggered ). A second bus is USB. We consistently said that USB bus on RPI4 has noise compared with USbridge . We also said that we do not see much difference in THD+N data and yet subjectively we hear DACs sound better . Of course, you can think that's because we make them. Still we give our honest opinion . The choice is yours in the end .

Deepspace57 yes we are working on it.

 

[kohlerm]

In this context, Is anyone aware of a project that takes the Boss2 components an adds a capable head phone amp?
Capable to me means 300-400mw at 37 ohm, because that is what I found is good enough for my Sundaras

 

[Bamyasi]

Bamyasi , RPI4 has multiple buses . Boss2 works on i2s . To remove hi frequency noise from lines we are using buffers (Schmidt triggered ). A second bus is USB. We consistently said that USB bus on RPI4 has noise compared with USbridge . We also said that we do not see much difference in THD+N data and yet subjectively we hear DACs sound better . Of course, you can think that's because we make them. Still we give our honest opinion . The choice is yours in the end.

It was shown by @amirm that the performance of I2S vs. USB is exactly the same when used to connect a DAC. Of course, you can still insist that RPi4 is an exception but without any evidence supporting such statement it really sounds weak.

Regarding your argument that you can hear difference that cannot be measured -- for your own good I would suggest you refrain of posting such statements here. Otherwise, you risk seriously compromising your company's reputation.

 

[johan]

Bamyasi

I design DACs using AP , Spectrum Analyzers and CROs. I trust my instruments . Yet , I have a subjective opinion . It generally matches the test data but not always . By definition , a subjective opinion cannot be measured. Note , I quickly point out , I see no correlation on THD+N .

Also note that we test on all our devices (and try to remove) hi frequency components ( beyond hearing limit) . None of our DACs uses dPLL (we use direct clocks/buffers with the exact multiple of audio frequency ) . We dont see much change on Jtest, Yet both are implemented .

We go above and beyond THD+N numbers with techniques that decrease noise (and can be measured directly ) that conventional wisdom says its not audible . I have no proof that its audible . And yet we spend countless hours to remove it.

Sorry but my statements are not controversial nor do I think it will impact our reputation . I give my opinion but also the hard data . The choice is yours .

 

[DeepSpace57]

@johan if you design dual dac (cs43198) and balanced config on the board with the same success as BOSS2, i guarantee you will kill all chi-fi dacs like d30pro, su-9.

 

[johan]

DeepSpace 57 we are designing it...our only question right now is if we use RPI or Xmos input..

 

[DeepSpace57]

DeepSpace 57 we are designing it...our only question right now is if we use RPI or Xmos input..

Maybe both ! Buyers can choose either of them while purchasing; personally Pi for sure. I hate cables.

 

[BikeSmith60]

Just ordered one of these for delivery in Europe. Had a very old Squeezebox die on the basement system and needed to replace. Still have 3 other Squeezeboxes all running Roon in addition to the main system which is all Naim. Hoping that the little Boss2 will make a decent Roon endpoint...

UPDATE: Boss2 received and installed with no problems. Was indeed Plug and Play as a Roon bridge and is functioning correctly. However, there are a few disappointing points:

1. Sound = very flat and non dynamic (as compared to a Squeezebox Classic on same exact system/parameters). Bass and lower-mids are perhaps too rounded and full while HF are VERY restrained. No bite or controlled sparkle on top. It works but sounds dull and disappointing.

2. Aluminum case feet are uneven and the unit is unstable on a flat surface. Not a major problem but the unit is so light along with unstable slippery feet it becomes a bit unwieldy once your RCA and ethernet cables are connected.

3. There are no instructions or indications on the functionality of the 4 filters which are accessible by remote control or by joystick. These filters can be disabled or enabled but there is no explanation on what they do.

Finally, I had to install an SSH client to immediately update the DietPi software and this was successful with no change in sound or functionality.

So quite frankly, what I thought was an inexpensive option for a qualitative Roon endpoint turns out to be clearly inferior to a lowly +10 year old Squeezebox in terms of sound and functionality. Yes, it does function as a wired streamer/DAC but there are no miracles, this is a very modest and very basic product with average or below-average SQ at best (IMHO, to my ears and on my system. YMMV of course).
Brgds.

 

[Veri]

Yes, it does function as a wired streamer/DAC but there are no miracles, this is a very modest and very basic product with average or below-average SQ at best (IMHO, to my ears and on my system. YMMV of course).
Brgds.

Kind of odd conclusion considering from Amir's testing it does well in basically all aspects. Maybe something else is at play..

 

[johan]

Hello Bike

Please allow a few days . Either psychological effect or because of the multiple supercaps burning , sound will improve.
Alternatively have you used Nirvana or cheaper PSU ? If cheaper PSU try using the earth lug below casing and connect to to earth. If Nirvana , use earth on front SW.

Let us know.

 

[BikeSmith60]

Hello Bike

Please allow a few days . Either psychological effect or because of the multiple supercaps burning , sound will improve.
Alternatively have you used Nirvana or cheaper PSU ? If cheaper PSU try using the earth lug below casing and connect to to earth. If Nirvana , use earth on front SW.

Let us know.

Hello Johan,
My feedback is obviously subjective according to my own (experienced) ears and in no way an attempt to disparage your products. I will certainly allow some more time of course and I did consider some minimal burn-in perhaps being necessary. The PSU is your cheap one which, while not being the best option, shouldn't compromise the high frequency response as I am hearing it. I can test other PSU options later. Also, unit is not grounded using the ground lug underneath. Can try that also. Lastly, I don't intend to return the device because it is already "good enough" for a basement/workshop system. I was expecting it to sound better though.
Brgds.

 

[BikeSmith60]

Kind of odd conclusion considering from Amir's testing it does well in basically all aspects. Maybe something else is at play..

Hello,
I believe in measurement tests and the results of these tests. I thought Amir's test and review were convincingly good which also prompted me to pull the trigger and order one. However, system synergy and room acoustics are not necessarily reflected in anybody's tests not to mention the listener's subjective aural impressions. In this case, and for the time being, I certainly trust my own judgement as an owner of the device in question.
Brgds.

 

[johan]

Boss2 was designed to be earthed . In fact Amir has tested the cheap PSU and said that there was noise . Only when he earthed the unit to the AP (in your case the same AC outlet as AMP, the noise went down and excellent measurements were taken .

So please use a wire and earth the underneath lug to any earth on AC. In some systems it makes a (very big?) difference .

Leave it on for a while and listen again . Let me know.

 

[Sir Sanders Zingmore]

@johan where can your Australian (potential) customers buy one of these?

 

[johan]

Hi Sir Sanders ,

we ship to Australia direct from our office in India...however please know that there will be a delay for the next 7 days since Bangalore entered a lockdown