ALLOaudio Posted July 11, 2018 Share Posted July 11, 2018 hi to all, as many of you heard , we have been working on a new DAC . We asked ourselves how its possible to bring true HIFI sound to the RPI. We wanted a price point thats accessible to everyone while blowing away any DAC made by anyone under 1000$ . Lets see if we succeeded 1. DAC IC First we chose a very capable IC , the ess9038q2m . This IC has excellent specs (theoretical THD+N at -120) and the analog stage (output) is left to the designer (more on analog stage below). One extra advantage of the ess9038q2m is DOP Of course we used super caps and everything in audio path is film caps and thin film R. 2. Clocks Any delta sigma IC is very sensitive to the clocks (jitter). We used the "ultra low jitter clocks from NDK NZ2520SDA http://www.ndk.com/en/products/search/clock/1190972_1433.html. We also made sure that power was filtered by 2 LDOs in series along with a HF filter. Noise tested is in uV. Of course we also used buffers (that also has its power filtered 3 times..) What we achieved is the lowest jitter ever (390fs) 3. Analog stage There are 2 kinds of analog stages , transfos and opamps. A lot of people swear by trans (with good reason) and others chose specific monolithic opamps. Still the consensus is that transfos are better as far as sound quality (but very expensive and bulky) and that opamps are better as far as THD+N numbers . If Opamps are used the quality of the PSU (opamps need dual rail 15V) is very important . Still we felt that opamps CAN be better than transfos.. We concentrated a lot of efforts in this analog stage . You see , monolithic (integrated circuits) opamps suffer from the fact that not enough real estate is available on the silicon die .( excellent article https://sparkoslabs.com/audio-op-amps-gain-seek-bandwidth/) So our choice was ultimately to build a discreet opamp (with IV stage we got 6 of them) while feeding it from a DC/DC convertor that has filters on input (+ LDO) and filters on output (+ LDOs) and of a course a common mode choke (each rail has independent filtering) for a total noise thats lower than 1mV However building an opamp is not a trivial task . What we did is partner with Sparkoslabs.com and used his excellent design (thx you Andrew the wizard) . One review of those opamps https://www.monoandstereo.com/2014/08/sparkos-labs-discrete-op-amps-review.html Each board is then hand trimmed (individually ) for DC offset (when board is warm to simulate conditions of a board that been running for at least 45 min)) and then programmed for THD+N compensation . So in essence Katana dac is an excellent implementation of the Ess9038q2m in Master Mode (we are the first to do so) , with a discreet stage made by 6 opamps running in class A amplification . THD+N numbers (1Khz , 0 dbfs , a weighted ) at -112.75 !!! Pricing at 249$ (US) and 259Eur (tax included) Release date 17 of July Link to comment
asdf1000 Posted July 11, 2018 Share Posted July 11, 2018 Hi @ALLOaudio Great stuff. What PCM and DSD sample rates are supported? Link to comment
ALLOaudio Posted July 11, 2018 Author Share Posted July 11, 2018 1 hour ago, Em2016 said: Hi @ALLOaudio Great stuff. What PCM and DSD sample rates are supported? PCM 384k , DSD64 & DSD128 on DoP mode asdf1000 1 Link to comment
jcbenten Posted July 11, 2018 Share Posted July 11, 2018 Sorry but I am not familiar with the RPi and Allo ecosystem but is this a standalone DAC or does it have to be mounted on a RPi? thanks. QNAP TS453Pro w/QLMS->Netgear Switch->Netgear RAX43 Router->Ethernet (50 ft)->Netgear switch->SBTouch ->SABAJ A10d->Linn Majik-IL (preamp)->Linn 2250->Linn Keilidh; Control Points: iPeng (iPad Air & iPhone); Also: Rega P3-24 w/ DV 10x5; OPPO 103; PC Playback: Foobar2000 & JRiver; Portable: iPhone 12 ProMax & Radio Paradise or NAS streaming; Sony NWZ ZX2 w/ PHA-3; SMSL IQ, Fiio Q5, iFi Nano iDSD BL; Garage: Edifier S1000DB Active Speakers Link to comment
ALLOaudio Posted July 11, 2018 Author Share Posted July 11, 2018 @jcbenten Always nice to welcome someone new to our hardware. We offer our DACs in 2 ways... The board alone (for those who want to mount it themselves). The player (assembled with the RPI in a case and ready to use). The Katana will be available by next week on our site. regards, Andre Link to comment
davide256 Posted July 11, 2018 Share Posted July 11, 2018 hmm, may be way out in left field but will ask. Could one use Burson discrete OP AMP's instead, or would they be inappropriate in the DAC? Burson spec sheet below https://drive.google.com/file/d/0Bxn23njCr8VCR19ELS1YOTMxV00/view Regards, Dave Audio system Link to comment
Panelhead Posted July 11, 2018 Share Posted July 11, 2018 This is impressive! Looks great and the price is very reasonable. Can ESS volume control be implemented? 2012 Mac Mini, i5 - 2.5 GHz, 16 GB RAM. SSD, PM/PV software, Focusrite Clarett 4Pre 4 channel interface. Daysequerra M4.0X Broadcast monitor., My_Ref Evolution rev a , Klipsch La Scala II, Blue Sky Sub 12 Clarett used as ADC for vinyl rips. Corning Optical Thunderbolt cable used to connect computer to 4Pre. Dac fed by iFi iPower and Noise Trapper isolation transformer. Link to comment
Ralf11 Posted July 11, 2018 Share Posted July 11, 2018 will balanced outputs be available? Link to comment
ALLOaudio Posted July 12, 2018 Author Share Posted July 12, 2018 @Panelhead we have hardware volume control available... Alsamixer @Ralf11 XLR output is available, you simply need to solder the connectors to the board Link to comment
rikhav Posted July 13, 2018 Share Posted July 13, 2018 What is the recommended power supply to be used ? And can the dac baord be powered separately I had read Allo is also designing a LPS Is it true? Link to comment
pooger Posted July 14, 2018 Share Posted July 14, 2018 On 7/12/2018 at 1:56 AM, ALLOaudio said: @Panelhead we have hardware volume control available... Alsamixer @Ralf11 XLR output is available, you simply need to solder the connectors to the board Neither of you replies really answer the questions. In terms of the volume control, is it attenuating the output, or using the internal ESS volume adjustment? In terms of balanced out, I'm assuming that one can hook up an XLR but it will be single ended—if it is balanced, please correct me. Link to comment
matthias Posted July 17, 2018 Share Posted July 17, 2018 Katana launched: https://www.allo.com/sparky/katana.html Matt "I want to know why the musicians are on stage, not where". (John Farlowe) Link to comment
rikhav Posted July 17, 2018 Share Posted July 17, 2018 What are the resolutions it supports? Link to comment
asdf1000 Posted July 18, 2018 Share Posted July 18, 2018 11 hours ago, rikhav said: What are the resolutions it supports? That's answered just a few posts up. rikhav 1 Link to comment
fphredd Posted July 24, 2018 Share Posted July 24, 2018 Can this be used with a passive pre-amp? Thx. Link to comment
ALLOaudio Posted July 24, 2018 Author Share Posted July 24, 2018 @fphredd , sorry, KATANA wont work as a passive pre-amp. regards Link to comment
fphredd Posted July 24, 2018 Share Posted July 24, 2018 21 minutes ago, ALLOaudio said: @fphredd , sorry, KATANA wont work as a passive pre-amp. regards I think you misunderstood. Will it feed a passive pre-amp was my actual question. Thanks so much! Link to comment
ALLOaudio Posted July 24, 2018 Author Share Posted July 24, 2018 Sorry, yes you can feed a pre-amp with the KATANA but please note that we output @ 2.5vrms, so not sure what the point would be. Link to comment
Panelhead Posted July 24, 2018 Share Posted July 24, 2018 1 hour ago, ALLOaudio said: Sorry, yes you can feed a pre-amp with the KATANA but please note that we output @ 2.5vrms, so not sure what the point would be. s Sorry this confuses you. There are several questions concerning a volume controller. The reference to an Allo controller confused me. I assume you are not using the volume control function included in the ESS chip. This is too bad. This is the best option. With 32 bits to work with it will never degrade the Sonics. A question was asked about following the Katana with a passive (non-buffered) volume control. I will share my ignorance by saying yes. But it depends on the amplifier used. Short, low capacitance cables, fairly high input impedance on amp both will improve combination. For me, using the ESS controller would be what I am after. Would give up Thunderbolt and four channel for now. 2012 Mac Mini, i5 - 2.5 GHz, 16 GB RAM. SSD, PM/PV software, Focusrite Clarett 4Pre 4 channel interface. Daysequerra M4.0X Broadcast monitor., My_Ref Evolution rev a , Klipsch La Scala II, Blue Sky Sub 12 Clarett used as ADC for vinyl rips. Corning Optical Thunderbolt cable used to connect computer to 4Pre. Dac fed by iFi iPower and Noise Trapper isolation transformer. Link to comment
maxijazz Posted July 24, 2018 Share Posted July 24, 2018 @ALLOaudio Do you have in plans a case for rpi/katana with enough room for mounting of pair of xlr sockets (that will be soldered out to katana board) in the case ? Link to comment
Panelhead Posted July 25, 2018 Share Posted July 25, 2018 On 7/17/2018 at 9:14 PM, Em2016 said: Also, is there room for the relay attenuator in the Katana player? 2012 Mac Mini, i5 - 2.5 GHz, 16 GB RAM. SSD, PM/PV software, Focusrite Clarett 4Pre 4 channel interface. Daysequerra M4.0X Broadcast monitor., My_Ref Evolution rev a , Klipsch La Scala II, Blue Sky Sub 12 Clarett used as ADC for vinyl rips. Corning Optical Thunderbolt cable used to connect computer to 4Pre. Dac fed by iFi iPower and Noise Trapper isolation transformer. Link to comment
matthias Posted July 29, 2018 Share Posted July 29, 2018 First review: https://volumio.org/allo-katana-dac-review/ Matt "I want to know why the musicians are on stage, not where". (John Farlowe) Link to comment
juliocat Posted August 2, 2018 Share Posted August 2, 2018 !!!!!!!!It's working!!!!!!!!! Sound it's really great even with just one LPS ALLOaudio 1 Hackintosh I7 16GB Ram, Roon, HQPlayer, Drobo 8 TB NAS, Raspberry Pi 3 NAA, Gustard X20 ES 9018 Xmos, Audio GD C39 Preamp, The First ONE DIY Amp, Monitor Audio GS20 Speakers, Monitor Audio RSW12 Subwoofer, PI Audio MagikBuss filter. Link to comment
ALLOaudio Posted August 2, 2018 Author Share Posted August 2, 2018 nice setup! try to power controller and RPI... what speakers are you using ? thanks Andre Link to comment
juliocat Posted August 2, 2018 Share Posted August 2, 2018 My speakers are http://www.aletheia-av.com/Aletheia-AV_productos_A-25II.html I'm planning on using 3 LPS, One for raspberry, One for microcontroller and one 15-0-15 for opamps Hackintosh I7 16GB Ram, Roon, HQPlayer, Drobo 8 TB NAS, Raspberry Pi 3 NAA, Gustard X20 ES 9018 Xmos, Audio GD C39 Preamp, The First ONE DIY Amp, Monitor Audio GS20 Speakers, Monitor Audio RSW12 Subwoofer, PI Audio MagikBuss filter. Link to comment
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