Good price/performance: HifiBerry DAC+ Pro OR Allo Boss ?

Dear all,

I'm preparing the XMas gift for my father, who doesn't have ANY kind of online/offline streamer source right now, just an old CD player.

I bought a Raspberry Pi 4 (4GB), it works with the external HDD wonderfully with our FLAC files through Volumio.

I'd like to give a huge boost to the sound quality and I think the aforementioned 2 DACs are pretty much the 2 options in this price range.

Which one would you buy if you just want a decent sounding analog output from a Pi4 ?

No big Hi-Res materials, no SACD, just simple FLAC files, our CD collection ripped with Exact Audio Copy and a good Plextor drive - that's it.

Both DAC hats have own dual-domain clocks, both can be powered by ultra-low-noise PSUs instead of the Pi's own, however, if they got fed by the Pi itself, both still have their own PSU-filtering circuit.. so focusing more on a really good sounding DAC without all the glitches of 'ultra-high-end' efforts like isolator, Kali, etc.. - which one would you opt for ?

Or to formulate my question the way around: can he be very satisfied with a Hifiberry DAC+ Pro ? (The Boss costs ~ $15 more).

I also like the true XLR feature of the Hifiberry DAC+ Pro XLR while the Boss doesn't have XLR out.

Next step would be upgrading his whole chain like throwing out the old Technics amp and getting a decent DIY Mosfet thing to drive the new speakers which would also be a DIY project..

I think the Hifiberry DAC+ Pro XLR would be as is alone a huuuge upgrade over the Pi's default sound, I just want maybe some confirmations regarding its sound quality.

Last but not least we with the Hifiberry we can simply convert the XLR outs to RCA on the other end (into the Technics amp) but the new chain would be XLR based anyway so it's more future-proof. Allo's RCA can't be made XLR so easy, it would need some additional circuit for sure. Just a practical point of view why I'd rather opt for the Hifiberry. (60% vs 40%) :)

Many thanks.
 

diyiggy

Member
2019-01-16 12:22 am
Hi,

Get IanCanada stuffs here or Allos' both seems to rule the markett with their ESS dac hats..

You need for better soubding result to isolate the Rpi from the dac hat with an isolator hat both those companies provide.

There is also a Rpi dac hat from Audiophonics which proved excelent music, and I sincerly believe Pa will be more than pleased with its sound: let look for philips dac chips hats at Audiophonics. Ernsternst member here wrote something about it in digital section. I think it's your best bet it also provide a good enough clock stage and sound is not only a dac chip but a whole... here it's a very good monney for what you get.

Just be aware Pa will need a little diy ability and IT to start these stacked things to output something or simply provide to him the deployment :) between Santa and a beer or wine. :cool:




Edit : dac chip from Philips is the TDA1387.
 
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Yeah, thanks ... :) Well, the isolator board, hmm. Not sure, I would definitely choose this for myself, aber my father won't recognize a difference I think.

Btw I'm connecting the DAC hat (any kind of..) via 40-pin flat ribbon GPIO breakout cable (exactly the same like old HDD IDE cables). This way the DAC gets a bit further from the Pi.. the latter will be in a separate shielded chamber anyway, within the DIY aluminum case.

Pa can do DIY no problem and Volumio is already able to recognize and drive this DAC.

Nevertheless, for myself I'm definitely going to use an isolator board too. (Maybe buy +1 later for Pa, too) :D

ESS DACs, especially the dual ES9038Q2M looks very promising. Does this board still need an output stage ? (And the XLR connectors in my case, soldered by us onto the board).

And the FifoPi ? And the Isolator board ? :scratch2:
 

ChrisP

Member
2003-12-04 2:48 pm
UK
I've been using a HiFIBerry Pro for a while now with a similar setup with no issues, sounds very good to me. Originally I was using it with a Pi3 but this died a sudden death a while back so I've gone back to an old Pi2 I had kicking around and it's more than powerful enough. A 4GB Pi4 is probably overkill tbh.

A useful trick is to partition the external drive with something like 32GB as the first partition and install the OS on there, this gives it a major speed boost as the sdcard is pretty slow. it'll still need the /boot partition to be on the sdcard to boot though.

I use a low power ssd as the external hd, overkill for the USB2 interface but damn quick and it can be powered directly from the Pi's USB. This is probably the main reason I may get a Pi4 one day.

I use Arch linux, running headless, with MPD as the music server software which is great and this thing is also running a small mail server with postfix & dovecot so I leave it running 24/7.

This is just off the standard PSU. Maybe one day I'll run the analogue section off a dedicated linear PSU, there's a jumper you can break for this.
 

diyiggy

Member
2019-01-16 12:22 am
Vortex, a flat gpio longer cable will not replace a noise isolation, you may just hear q difference cquse bias. Best monny could be Allo isolator reclocked, and best Iancanada's...
Father will genuinly enjoy the tda1387 hat directly stacked imo.... wether an isolator.
 
Thank you Gentlemen. I think I won't fit into time with my order anyway so I decided to spare the money now and buy him a IANCANADA DAC in January, the dual ES9038Q2M.

Due to the pretty flat casing the DAC would still fit somehow onto the Pi, but not with an isolator so the final solution is to place the DAC and Pi next to eachother, Pi in the noisy section with linear PSU and LDO-regulated side, DAC on the other side, and a thick aluminum wall between them, with a thin slot on the bottom for the flat ribbon cable.

Q1: What would you recommend, put the isolator board (and if yes, which one?) onto the Pi first and then do a breakout with the cable, or better put the cable directly onto the Pi and go with the isolator to the other side, where the DAC is meant to be ?


Q2: One of my colleagues sells his Pi2 B for chips, probably. Shall I jump on it and is it sufficient for the task on the long run ? Less heat + I could use the Pi4/4G for myself for a completely different project. There's only one option talking for the Pi4: I might install OpenVPN onto the system of Volumio and have it automatically connect to my router always (without forcing all traffic into the tunnel). This way I can safely share any kind of material with my father easily, but this solution means some load on the CPU, we both have fast internet access.


For storage I'll buy a USB3<->M.2 SSD adapter board link and build it into the chassis too, right next to the Pi, plugged in directly. A 500GB WD Green SATA drive will do the trick I think, seek time and cool operation is more important than being fast in requential reads. Thanks for the partitioning idea, very useful.
 
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ChrisP

Member
2003-12-04 2:48 pm
UK
some stats for a pi2. the iostats are averaged over a couple of minutes or so whilst playing a flac from the ssd.
meminfo is from about 5 min after a reboot.

[email protected] ~]# iostat
Linux 4.19.86-1-ARCH (mail.xx.xx.uk) 09/12/19 _armv7l_ (4 CPU)

avg-cpu: %user %nice %system %iowait %steal %idle
1.82 0.00 1.54 0.31 0.00 96.33

Device tps kB_read/s kB_wrtn/s kB_dscd/s kB_read kB_wrtn kB_dscd
mmcblk0 0.78 23.30 0.00 0.00 7044 0 0
sda 18.39 514.98 38.77 0.00 155730 11724 0


[[email protected] ~]# cat /proc/meminfo
MemTotal: 994676 kB
MemFree: 709736 kB
MemAvailable: 897732 kB
Buffers: 53748 kB
Cached: 135592 kB
SwapCached: 0 kB
Active: 77752 kB
Inactive: 147316 kB
Active(anon): 35972 kB
Inactive(anon): 268 kB
Active(file): 41780 kB
Inactive(file): 147048 kB
Unevictable: 0 kB
Mlocked: 0 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 994676 kB
LowFree: 709736 kB
SwapTotal: 1048572 kB
SwapFree: 1048572 kB
Dirty: 72 kB
Writeback: 0 kB
AnonPages: 35776 kB
Mapped: 54508 kB
Shmem: 464 kB
Slab: 37128 kB
SReclaimable: 15484 kB
SUnreclaim: 21644 kB
KernelStack: 1136 kB
PageTables: 2056 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 1545908 kB
Committed_AS: 188064 kB
VmallocTotal: 1064960 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
Percpu: 592 kB
CmaTotal: 8192 kB
CmaFree: 6288 kB
[[email protected] ~]#
 

diyiggy

Member
2019-01-16 12:22 am
Wow....

So no bit perfect or longer buffering ? Better to have flash drive or is it due to the Pi ic ?
Same for wave files?
One wajd the Pi is better as standalone renderer.... I personnaly give this task on a synology NAS for server task and flac decompressipn tak (while I'm not sure it is better, lol...)
 
What is the purpose of m2 ssd drive over a bigger sata 3 SSD ? Is it just size or did you plane it for other things like electrical noise or what?

I think I don't really understand your question.

M.2 is a form factor, a physical connector, not the protocol or bus behind it. It can be SATA and NVMe (PCIe based) as well.

click

- SATA versions (M.2) used to run cooler due to less stress on the chips, sometimes by intention (cheap drives, low price), sometimes by design (SATA maximum transfer speed cap reached long ago).

- In contrast, NVMe (M.2) types are designed (the mainstream at least) to be faster than SATA types so the stress on their chips is also bigger. The result is more heat, they can sustain extreme speeds but most of them only for a short period, then thermal throttling hits in and goodbye performance - or the user cools them with a proper heatsink.


Therefore, for a Volumio based flac streamer I'd opt for the SATA types, from a good reliable type (reading reviews and tests helps a lot). Transfer speed isn't needed that much so a conventional 2.5" HDD would be fine for the job but quick random access (seek) times are important when doing indexing and other filesystem activities, not only just playing FLAC files. The best compromise in this is a SATA drive.

Classic SATA drives in external case (non-M.2) are also okay imho, it's really up to the price/performance. Whichever version I take, a cheap 2.5" usb3 to sata or USB3 to M.2 does the trick and I'm good.
 

diyiggy

Member
2019-01-16 12:22 am
thanks, I was not aware of that size case.


My understanding is the electronic noise is greater from the source when a lot of mA are used to feed the fifferent loads and devices before the dac chips and he can be heard. Thus many people here try to reduce the electronique noise going towards the dac inputt.


Many noticed an improvment (if the hifi system is clear enough) when two Rpi are used (Server and library file splitted from the further Rpi renderer) or a standalone Rpi renderer (with a lighted distro & playback soft to reduce onboard chips use) feeded through ethernet cable or wifi (though Wifi seems noisy due to the Rpi layout which is not designed for audio only since the beginning, then people tried portable wifi router with ethernet outputt towards the Rpi with both the hotspot and the Rpi powered from battery). But those splits are the last refinments. But a standalone will do in most of hifi systems, anyway all the Rpi music distros have this choice today.



SD cards reader was an other way to reduce noise towards a DAC board: very low current embeded and no noise from a Rpi or laptop or router. If the M2 size case is in between the SD Card and a 2.5 full SSD in term of mA current needs I surmise it can help to make your Rpi quieter... perhaps ?! You will always have till some noise from the Rpi though!


Check for example Soundcheck member's threads here or in his blog soundcheck's - [email protected]


your best bet is not to split the dac hat from the Rpi with a flat cable (but for your height purpose) in term of sound but split your box for two Rpi for a further improvment the day you want to check such solutions.


hope that helps...


So you will take an ESS hat for father too ?
 
Wow, thanks for these extra few tips.

ESS ? So far I thought yes, then it turned out it still needs an output stage module (bought separately), clocks, extra control board to choose between filtering modes, etc. Uh.

That would be overkill I think, compared to a ready-to-use Allo Boss or Hifiberry DAC+ Pro XLR with their own onboard clocks. I also hear good feedback about the AKM type DACs, looking at the specs of this one here right now (although I probably need rather XLR outs so maybe I'll revert back to the good-old Hifiberry DAC+ Pro XLR combined with a FifoPi or similar isolator board kind of stuff..).

Leaving the door open for future upgrades - or myself, with a 2nd Pi because I don't have that kind of a streamer yet - I might opt for a simple PS Audio compatible I2S HDMI out (IAN CANADA HDMIpi Transmitter I2S / DSD / DoP to HDMI - Audiophonics) and try an external DAC fed by this I2S signal, e.g. the Matrix Audio X-Sabre Pro (non-MQA version). But that's a later story, now father has to make a quantum leap with his whole gear, pretty much everything of his chain is outdated and poor sounding. :(
 
Yepp, that's where I've arrived too in the last days. A bit more realistic plan and this would still be "WOOOW" for him, after a dark & dull sounding, lifeless Technics amp & CD player.

Next are the speakers anyway. I should have begun with them first, but this little Volumio solution isn't only about SQ but about UX and fun too. This alone won't save the world, but when I redesign his boxes with new AMT tweeters, new midranges, new proper bass drivers and new crossover, then comes a whole new life then.

Thank you all for the supportive comments. Great forum, love it. :)
:cheerful: :cheers: