I power the PurePi and consequently also the Rpi 4 with a SONCOZ LP1 linear power supply. The FifoPi Q7 is powered by the J5's 3.3v and the ProtoDac by the J3 at 5v
The FifoPi Q7 does not have 5V power on the GPIO. It has 3.3V on GPIO pins 2 and 4. See the chart in post #11. Yes, the FifoPi Q3 and Q7 have a nonstandard GPIO that cannot be changed. That is the problem.
To get around this problem, ProtoDAC needs to be powered with 5VDC using the 5V and GND solder pads between the RCA jacks. You can solder a green screw terminal with 5mm pin spacing, if you prefer. Then use the stacking header with pins 2 and 4 removed to prevent 5V from feeding back to the Q7 GPIO, while retaining the required ground and I2S connections.
This is not only an issue of operation. Even if ProtoDAC will operate at 3.3V, it will not sound as good as it does at 5V.
I have seen assembled ProtoDACs in Holland . I have no affiliation. I have not reviewed the parts selection.
Last edited:
@hifiamps Thanks a lot for your detailed reply. I am waiting for a StationPi Pro, where the Raspberry will be positioned on one side (powered by a 5V ultra capacitor conditioner), and on the other side the FifoPi Q7 will be positioned (powered by a 5V and a 3V). In the photo you can see the previous layout before the ultra capacitors were ready. For the moment I am waiting for the new StationPi Pro to arrive (the previous one was faulty). I wonder whether I can use the 5V on the 'right' side of the StationPi Pro for the ProtoDAC, too. Do you think it could work? I have two 5V and one 3.3V power outputs, that I may use for various HATs.
Another question I have, and apologies if it's off-topic or silly, but -being I am a novice on HAT DACs- I am wondering which Philips chip sounds better, namely the TDA1387, the TDA1543 or the TDA1541A?
Thanks in advance for your response.
Panos
Another question I have, and apologies if it's off-topic or silly, but -being I am a novice on HAT DACs- I am wondering which Philips chip sounds better, namely the TDA1387, the TDA1543 or the TDA1541A?
Thanks in advance for your response.
Panos
Attachments
MaxB_70. I am impressed with the coincidental similarities between our systems. I used to drive my NOS-R2R DAC with a USB cable from my Mac than ran Audirvana. And then I purchased a Wiim Pro. Oh, and by the way, my turntable is a renovated Lenco L75 with a heavy, custom-made plinth and two 12" tonearms.
So, the ProtoDac rivals the Lenco? Wow! That's a bold statement.
In any case, I am curious about the ProtoDAC and how I can place it on the FifoPi Q7. I understand that the ProtoDAC needs 5V, but the FifoPi Q7 has only 3.3V (on the clean side). I am afraid that I am still learning the Ian Canada HAT stuff. -))
Attachments
I don't have any experieince with StationPi Pro. Just looking through the manual, 5V is applied to J5 on the right side. Q3 and Q7 see the standard RPi GPIO pin 2 and 4 5V on their bottom GPIO, but they don't pass it through to the topside GPIOs. They use the isolated 3.3V supply to pins 2 and 4.
I have never heard a TDA1541A. I would like to. I was never interested in building a TDA1541 DAC not only due to cost and complexity, but also the problem with fake chips.
I did listen to a Chinese TDA1543 DAC, but it does not sound nearly as good as the TDA1387 in my opinion. I should mention a successful TDA1543 DAC by Peter Daniel described in "Pushing the limits of TDA1543 NOS DAC". Note that the Peter Daniels DAC is not only NOS, but also output filterless, like ProtoDAC. Note that Peter prefers the thick film Caddock TF020 over the TX2575 as I/V resistor. Others prefer the Z-foil. Note that both are noninductive. I would estimate that the TX2575 are 30% better sounding than premium metal film resistors. Just to put a number to it.
The TDA1387 X8 modules received good reviews when used as a substitute for the TDA1541. Many of the existing TDA1387 DACs use eight chips in passive I/V mode. Having the Raspberry Pi with excellent software like Moode permits direct I2S to the TDA1387 X8 module. I basically simplified and optimized the TeraDak TDA1387*8 DAC, which I liked a lot, and it sounded even better. The TDA1387X8 modules have just been sitting there. Let's use them.
I have never heard a TDA1541A. I would like to. I was never interested in building a TDA1541 DAC not only due to cost and complexity, but also the problem with fake chips.
I did listen to a Chinese TDA1543 DAC, but it does not sound nearly as good as the TDA1387 in my opinion. I should mention a successful TDA1543 DAC by Peter Daniel described in "Pushing the limits of TDA1543 NOS DAC". Note that the Peter Daniels DAC is not only NOS, but also output filterless, like ProtoDAC. Note that Peter prefers the thick film Caddock TF020 over the TX2575 as I/V resistor. Others prefer the Z-foil. Note that both are noninductive. I would estimate that the TX2575 are 30% better sounding than premium metal film resistors. Just to put a number to it.
The TDA1387 X8 modules received good reviews when used as a substitute for the TDA1541. Many of the existing TDA1387 DACs use eight chips in passive I/V mode. Having the Raspberry Pi with excellent software like Moode permits direct I2S to the TDA1387 X8 module. I basically simplified and optimized the TeraDak TDA1387*8 DAC, which I liked a lot, and it sounded even better. The TDA1387X8 modules have just been sitting there. Let's use them.
Last edited:
@pkonstantinidis
My recommendation is to build ProtoDAC (or have it built for you) with GPIO header pins 2 and 4 removed, and a screw terminal soldered to the 5V/GND pads. 😉
My recommendation is to build ProtoDAC (or have it built for you) with GPIO header pins 2 and 4 removed, and a screw terminal soldered to the 5V/GND pads. 😉
@hifiamps thanks a lot for your reply and recommendation. I understand that you like the TDA1387 more than the TDA1543. Would you be so kind as to elaborate a bit why that is? I happen to have a DAC that's based on TDA1453, which I like quite a lot. So, if the TDA1387 sounds (even) better, that's very promising to me.
The only thing is how I can power the ProtoDAC with the required 5V. Do you think that the 5V voltage that I provide to the J5 of the StationPi Pro, I could also supply in parallel to the ProtoDAC. Would that work or can it damage the FifoPi Q7, connected below the ProtoDAC?
Finally, about the ProtoDAC itself, which are the best parts that I can use (e.g. caps, resistors, RCA terminals, etc), in order to maximize its (sonic) performance?
Thanks
The only thing is how I can power the ProtoDAC with the required 5V. Do you think that the 5V voltage that I provide to the J5 of the StationPi Pro, I could also supply in parallel to the ProtoDAC. Would that work or can it damage the FifoPi Q7, connected below the ProtoDAC?
Finally, about the ProtoDAC itself, which are the best parts that I can use (e.g. caps, resistors, RCA terminals, etc), in order to maximize its (sonic) performance?
Thanks
The "Lusya HIFI TDA1543*4 decoder USB OTG DAC external bile decoder board" was the one I listened to as I was screening NOS DACs. It doesn't seem to be available.
The TDA1387X8 DACs just seemed to have lower distortion, more "musical". Better overall. Note that most of the TDA1387 DACs had I/V resistors that were too high a value, usually 560R. Even though they were clipping they sounded better. The TDA1543 DACs may have also had too high an I/V resistor value as well. My TeraDak TDA1387*8 DAC had fixed this problem, and it used a 390R metal oxide I/V resistor. I think originally they also used a 560R.
I personally think the only things you can upgrade on the ProtoDAC kit are the WIMA output coupling caps. I chose the WIMAs for decent sound at low cost. One ProtoDAC kit customer told me that the ClarityCap CMR was much more detailed. Note that they are very large in diameter and not inexpensive. Boutique caps can get very expensive.
The capacitance value should be 4.7-10uF. Note that some caps (Jantzen Standard Z in 10uF, for example) can smear. They sound better in a lower value. Any voltage film cap will work. The lower voltage rating, the physically smaller the cap.
See the Humble Homemade HiFi cap ratings.
If the next component in the chain (preamp, for example) has confirmed input DC blocking capacitors, you could actually substitute a wire for the WIMAs. The DC voltage at the I/V resistors is about 2V.
The TDA1387X8 DACs just seemed to have lower distortion, more "musical". Better overall. Note that most of the TDA1387 DACs had I/V resistors that were too high a value, usually 560R. Even though they were clipping they sounded better. The TDA1543 DACs may have also had too high an I/V resistor value as well. My TeraDak TDA1387*8 DAC had fixed this problem, and it used a 390R metal oxide I/V resistor. I think originally they also used a 560R.
I personally think the only things you can upgrade on the ProtoDAC kit are the WIMA output coupling caps. I chose the WIMAs for decent sound at low cost. One ProtoDAC kit customer told me that the ClarityCap CMR was much more detailed. Note that they are very large in diameter and not inexpensive. Boutique caps can get very expensive.
The capacitance value should be 4.7-10uF. Note that some caps (Jantzen Standard Z in 10uF, for example) can smear. They sound better in a lower value. Any voltage film cap will work. The lower voltage rating, the physically smaller the cap.
See the Humble Homemade HiFi cap ratings.
If the next component in the chain (preamp, for example) has confirmed input DC blocking capacitors, you could actually substitute a wire for the WIMAs. The DC voltage at the I/V resistors is about 2V.
that's really impressive ! such number of similar equipments (My Wiim Pro has been shipped to Greece on August of 2023) ! I may be not accurate on my answer : ProtoDAC with PurePI (no Q7 stacked) is so good that I can really enjoy it. But this kind of flesh and body you can feel with the Lenco is still not present with the digital stuff.
By the way, during 2 minutes I heard PurePi, RPI (external 5V powered), Q7(3.3 from PurePI), ProtoDAC (5V supplied by PurePi) : it is magical ! depth, wideness, tonality of the instruments are very enjoyable. Mark @hifiamps made you a good offer : mounted and wires soldered on pad, that's fair.
Your L75 is very beautiful ; Do your RCA plugs are KLE ? Good work. I share you mine with my self build plinth, phono cables and mounted strobe.
Attachments
@MaxB_70 Here is the key statement in the PurePi manual: "PurePi is functionally the equivalent to a ConditionerPi 5V plus a LifePO4Mini 3.3V."
From the ConditionerPi manual: "Note: It is recommended keeping the external power supply always on with using the ConditionerPi on-board ON/OFF switch only."
This also applies to PurePi.
From the ConditionerPi manual: "Note: It is recommended keeping the external power supply always on with using the ConditionerPi on-board ON/OFF switch only."
This also applies to PurePi.
@hifiamps
setup has been charged the whole afternoon.
video 1 shows that even PurePi off (0V at J5), Q7 is powered, D2 brights. When I remove the external RPI 5V charger, Q7 is not powered anymore. I assume that Q7 is powered by RPI GPIO. What do you think ?
PurePi doesn't seem to work fine to : video 2 shows, when PurePI is powered on, D8 doesn't bright even D4 shows full batteries. I tested 0V at J5.
When ProtoDAC is not stacked on Q7, Volumio is able to play a full album.
When ProtoDAC is stacked on Q7 and plugged in Q7 J5 , setup stops quickly.
So I think to ask @iancanada to checkup the boards.
https://drive.google.com/file/d/1Qg9SCda-WhlLpWZMM_9lzwrDTTx-w9s0/view?usp=sharing
https://drive.google.com/file/d/1Qe6CrNutMQOz1UTu6Sxt-BSi2WEOyaZG/view?usp=sharing
setup has been charged the whole afternoon.
video 1 shows that even PurePi off (0V at J5), Q7 is powered, D2 brights. When I remove the external RPI 5V charger, Q7 is not powered anymore. I assume that Q7 is powered by RPI GPIO. What do you think ?
PurePi doesn't seem to work fine to : video 2 shows, when PurePI is powered on, D8 doesn't bright even D4 shows full batteries. I tested 0V at J5.
When ProtoDAC is not stacked on Q7, Volumio is able to play a full album.
When ProtoDAC is stacked on Q7 and plugged in Q7 J5 , setup stops quickly.
So I think to ask @iancanada to checkup the boards.
https://drive.google.com/file/d/1Qg9SCda-WhlLpWZMM_9lzwrDTTx-w9s0/view?usp=sharing
https://drive.google.com/file/d/1Qe6CrNutMQOz1UTu6Sxt-BSi2WEOyaZG/view?usp=sharing
the external power is always on : charger without switch. Only use S2 on PurePi. Thank you Mark.
I am a complete novice with the Ian Canada products. Currently, I am only using the ultracap 5V supply of PurePi to power my stack (RPi ZeroW/Allo Kali/ProtoDAC) and it works fine.
The batteries are installed, but I am not using the 3.3V supply. Charging power supply is plugged in all the time. If I unplug the charging supply, my stack is powered until the ultracaps are discharged (about 1 minute).
I have never actually measured 3.3V at the J2 terminal. The batteries measure fine. I think it shuts off the 3.3V supply without a load? Just a guess.
Status LEDs while my stack is being powered with 5V: D8 OFF, D1 ON, Pretty blue D13 ON, D4 OFF, D10 ON, D11 ON, D6 ON.
The manuals are incomplete/inadequate IMHO.
The batteries are installed, but I am not using the 3.3V supply. Charging power supply is plugged in all the time. If I unplug the charging supply, my stack is powered until the ultracaps are discharged (about 1 minute).
I have never actually measured 3.3V at the J2 terminal. The batteries measure fine. I think it shuts off the 3.3V supply without a load? Just a guess.
Status LEDs while my stack is being powered with 5V: D8 OFF, D1 ON, Pretty blue D13 ON, D4 OFF, D10 ON, D11 ON, D6 ON.
The manuals are incomplete/inadequate IMHO.
Added a small load (420R resistor) to the 3.3V terminal J2, and 3.3V now appears. There is no change in status LEDs. Remove the load, and 3.3V switches off.
Both the 5V and 3.3V have switching MOSFETs near the output terminals.
Both the 5V and 3.3V have switching MOSFETs near the output terminals.
Switch S2 to off. All LEDs off except D10 and D11 remain on. Unplug the power bank and D10 and D11 still on for another minute or so, then all LEDs off.
@pkonstantinidis @MaxB_70
When I posted the ProtoDac video I did not realize that pin 2 and 4 of the Clean side of the Q7 is 3.3v and not 5v.
So it is better to use a Gpio extension and cut pin 2 and 4 and feed the ProtoDac from a separate 5v or from pure pi
I got the ProtoDac ground from the pcb an +5v from the positive base of the capacitor.
Hi Gabi (apologies in case I have misspelled your name),
thanks very much for your feedback. Much appreciated.
As I already have two 5V UCconditioners, both for the StationPi Pro (dirty and clean side, respectively), I am wondering whether I might use the clean side 5V UCconditioner, to power both the clean side of the StationPiPro and the ProtoDAC in parallel. Do you think that would work?
Furthermore, I am interested in the comparison of the ProtoDAC with the TDA1541A-based that you are building. How do they compare sonically?
Thanks again.
thanks very much for your feedback. Much appreciated.
As I already have two 5V UCconditioners, both for the StationPi Pro (dirty and clean side, respectively), I am wondering whether I might use the clean side 5V UCconditioner, to power both the clean side of the StationPiPro and the ProtoDAC in parallel. Do you think that would work?
Furthermore, I am interested in the comparison of the ProtoDAC with the TDA1541A-based that you are building. How do they compare sonically?
Thanks again.
That should work when I finish the tda project I will try to do a ab test and report
Looking forward to that a/b comparison, @Gabster 2000 . What is the highest resolution that the ProtoDAC can handle? 24bits or even 32bits? 96kHz or even 192kHz?
Thanks.
Thanks.
ProtoDAC is an I2S (slave), NOS (nonoversampling), multibit DAC HAT using eight parallel Philips TDA1387 chips, passive I/V and is capable of 16 bit 384kHz sample rate PCM conversion. It can play higher resolution files by truncating to 16 bits. It could be fed dithered 16 bit samples from 24 bit files. See the project thread and Builder Guide. Info at Moode Audio.