A comment on bit depth. 16 bits gets you 98dB SNR. That is actually more than enough since, most recordings don't have that signal to noise.
An exchange I had with a ProtoDAC kit customer from December 2023:
Hi there,
This few lines to let you know that the TDA1387 chips worked for all of 4 days and then the music stopped.
I had ordered few of those in China and I could quickly substitute the one I received from you.
Could you possibly send me a replacement chipset?
Thanks in advance
The DAC works once again.
Hi,
I am sorry for the trouble you are having. It is unlikely that all eight chips went bad at once. There is likely another explanation for the failure. With both channels going out at the same time, the most likely explanations are loss of power to the module or loss of I2S signal to the module.
Mark
Well I cannot explain what happened but once I substituted the chipset the board was working perfectly. Hence my conclusion that something is wrong with the chipset .
OK. I can issue a partial refund to cover the replacement cost of the module.
Done. And thank you.
After sending the email informing of the Ian 3.3V issue:
Mark a couple of weeks ago I connected the Protodac to a 5v power supply. I did not think about trying the “defective “ chip in this new configuration. If it works I owe you $10!
A few hours later:
I owe you!
Hi there,
This few lines to let you know that the TDA1387 chips worked for all of 4 days and then the music stopped.
I had ordered few of those in China and I could quickly substitute the one I received from you.
Could you possibly send me a replacement chipset?
Thanks in advance
The DAC works once again.
Hi,
I am sorry for the trouble you are having. It is unlikely that all eight chips went bad at once. There is likely another explanation for the failure. With both channels going out at the same time, the most likely explanations are loss of power to the module or loss of I2S signal to the module.
Mark
Well I cannot explain what happened but once I substituted the chipset the board was working perfectly. Hence my conclusion that something is wrong with the chipset .
OK. I can issue a partial refund to cover the replacement cost of the module.
Done. And thank you.
After sending the email informing of the Ian 3.3V issue:
Mark a couple of weeks ago I connected the Protodac to a 5v power supply. I did not think about trying the “defective “ chip in this new configuration. If it works I owe you $10!
A few hours later:
I owe you!
Hi gentlemen !
2 weeks out of home. I have done my homework today. For this try,
Everything works fine now. I assume that the problem was from the USB C cable connected to PurePi. With Thunderbolt 4, the curent seems high enough. The setup is stable.
A/B listening with Cary 800 DVP owned by a friend. ProtoDAC/Q7 has little more deepness and wideness. The big difference is ProtoDAC/Q7 is more enjoyable. Music is easier with it.
Thank you all for your help.
Many thanks to @hifiamps for your advisements to achieve this setup. 5V is much better than 3V 😉
Thank to @Gabster 2000 to inspire us with his YT channel. It helps me to jump to this enjoyable journey !
Max
2 weeks out of home. I have done my homework today. For this try,
- PurePi powered by Apple MPB charger with Thunderbolt 4 cable (next step should be transformers, ultracapacitors and regulators)
- RPI by generic charger 3A@5V (thank you Mark),
- Q7 powered by 3.3V from LifePO4 batteries mounted on PurePI board (next step will be ultracapacitors)
- ProtoDAC (love it !) powered by PurePI 5V ultracapacitors with GPIO 2 and 4 pins cut (thank you Mark).
Everything works fine now. I assume that the problem was from the USB C cable connected to PurePi. With Thunderbolt 4, the curent seems high enough. The setup is stable.
A/B listening with Cary 800 DVP owned by a friend. ProtoDAC/Q7 has little more deepness and wideness. The big difference is ProtoDAC/Q7 is more enjoyable. Music is easier with it.
Thank you all for your help.
Many thanks to @hifiamps for your advisements to achieve this setup. 5V is much better than 3V 😉
Thank to @Gabster 2000 to inspire us with his YT channel. It helps me to jump to this enjoyable journey !
Max
Attachments
@pkonstantinidis I am listening to Molly Tuttle's City of gold (96/24) just after 44.1/16. All from Qobuz (Volumio, Wifi). I can't hear any difference.
@pkonstantinidis μην το αναφέρεις (Does Google work fine ?)
A/B listening with Cary 800 DVP (15k€) or/and Helixir DAC (French brand from Marseille, 8K€). Both, owned by a friend, are about to be sold right now !! 🙂
When I will done by mounting mine, I will help him to do it. Q7 brings some flesh to the singers and makes sound ProtoDAC so enjoyable. As L75 owner I am pretty sure you can feel what I mean. 7 hours straight listening and I want more !!
A/B listening with Cary 800 DVP (15k€) or/and Helixir DAC (French brand from Marseille, 8K€). Both, owned by a friend, are about to be sold right now !! 🙂
When I will done by mounting mine, I will help him to do it. Q7 brings some flesh to the singers and makes sound ProtoDAC so enjoyable. As L75 owner I am pretty sure you can feel what I mean. 7 hours straight listening and I want more !!
@MaxB_70
If I understand correctly, the Cary DMS-800DVP is just a streamer and the Helixir is a DAC. So, you compared those two combined with the FifoPi Q7 and the ProtoDAC, right?
As a matter of fact, I am sure the FifoPi Q7 is definitely a great component. I have also finished my streamer based on Ian Canada's components, including two LinearPi, three UCconditioners, a StationPi Pro, a FifoPi Q7 and a TransportPi AES. You can see all of them here...
I can confirm that the streamer sounds great. Much more detail, clarity and sense of reality than before using the streamer. But my question is more about the ProtoDAC. I wonder whether using the ProtoDAC is better than using a dedicated external DAC (say, worth 2-3K€).
In any case, when you say the that FifoPi Q7 + ProtoDAC compares favorably with your Lenco L75, I can fully appreciate that your've placed the bar at a very considerable height. Impressive!
(enclosed a photo of my Lenco L75)
If I understand correctly, the Cary DMS-800DVP is just a streamer and the Helixir is a DAC. So, you compared those two combined with the FifoPi Q7 and the ProtoDAC, right?
As a matter of fact, I am sure the FifoPi Q7 is definitely a great component. I have also finished my streamer based on Ian Canada's components, including two LinearPi, three UCconditioners, a StationPi Pro, a FifoPi Q7 and a TransportPi AES. You can see all of them here...
I can confirm that the streamer sounds great. Much more detail, clarity and sense of reality than before using the streamer. But my question is more about the ProtoDAC. I wonder whether using the ProtoDAC is better than using a dedicated external DAC (say, worth 2-3K€).
In any case, when you say the that FifoPi Q7 + ProtoDAC compares favorably with your Lenco L75, I can fully appreciate that your've placed the bar at a very considerable height. Impressive!
(enclosed a photo of my Lenco L75)
Attachments
@pkonstantinidis , I do like your job ; I am sure I will have some questions when I try to setup transformers, regulators and ucconditionner.
When I said or/and, it is because Cary DMS-800DVP his both streamer/DAC and Helixir is only a DAC. Then we compared Cary and Helixir DACs (both feed by Cary streamer part). The best was the Cary. Dynamics, flesh are pretty noticeable with the Cary. Then we compared Cary with RPI/Q7/Protodac. Cary sounds like my Linn Soundek LP12 I owned from 2008 to 2013 : Balanced, good timing but a little skinny. Q7/ProtoDAC sound is more framed, physical presence improved compared to Cary. But I am not able to compare ProtoDAC alone with other DAC because I don't have a TransportPi.
I compared Q7/PRotoDAC with L75 listening Paul Simon Graceland album. Q7/PRotoDAC did it well, pretty well. You're right, Q7 is such a good component. But L75 has more dynamics, incarnations. You can feel the singers, the instruments. Vinyl...
When I said or/and, it is because Cary DMS-800DVP his both streamer/DAC and Helixir is only a DAC. Then we compared Cary and Helixir DACs (both feed by Cary streamer part). The best was the Cary. Dynamics, flesh are pretty noticeable with the Cary. Then we compared Cary with RPI/Q7/Protodac. Cary sounds like my Linn Soundek LP12 I owned from 2008 to 2013 : Balanced, good timing but a little skinny. Q7/ProtoDAC sound is more framed, physical presence improved compared to Cary. But I am not able to compare ProtoDAC alone with other DAC because I don't have a TransportPi.
I compared Q7/PRotoDAC with L75 listening Paul Simon Graceland album. Q7/PRotoDAC did it well, pretty well. You're right, Q7 is such a good component. But L75 has more dynamics, incarnations. You can feel the singers, the instruments. Vinyl...
@MaxB_70 If I understand correctly, you have placed your FifoPi Q7 on top of the RPi. (And the ProtoDAC on top of the FifoPi Q7).
I've also tried the FifoQ7 on top of the RPi, and the RPi powered by its standard 5V power supply. When I used the StationPi Pro to separate the RPi and the Fifo Q7, and also powered everything with Ian Canada's ultra capacitors (UCconditioners), the sound quality improved considerably.
So, perhaps you may still have some further room for improvement, which is not just marginal. If you are happy now, you may be much happier if you proceed to some further adjustments/modifications.
I've also tried the FifoQ7 on top of the RPi, and the RPi powered by its standard 5V power supply. When I used the StationPi Pro to separate the RPi and the Fifo Q7, and also powered everything with Ian Canada's ultra capacitors (UCconditioners), the sound quality improved considerably.
So, perhaps you may still have some further room for improvement, which is not just marginal. If you are happy now, you may be much happier if you proceed to some further adjustments/modifications.
@pkonstantinidis " you have placed your FifoPi Q7 on top of the RPi. (And the ProtoDAC on top of the FifoPi Q7)." Exactly. PurePI supply Q7 (LifePO4 batteries) and ProtoDAC (ultracapacitors).
For further improvements, you're totally right :
In my order to Ian (GP2023), I have also
StationPi SMT,
UcConditionerMkII 3.3V ( Maxwell 325F 2.7V UC to be ordered) and UCPure for Q7
UcBalancer ( eaton 3000F 2.7V UC to be ordered) for ProtoDAC
then RPI will be supplied by PurePi
In few weeks I will have time to set it up 😉
For further improvements, you're totally right :
In my order to Ian (GP2023), I have also
StationPi SMT,
UcConditionerMkII 3.3V ( Maxwell 325F 2.7V UC to be ordered) and UCPure for Q7
UcBalancer ( eaton 3000F 2.7V UC to be ordered) for ProtoDAC
then RPI will be supplied by PurePi
In few weeks I will have time to set it up 😉
@MaxB_70 I am sure you will see very significant improvement, once you separate the RPi and the FifoPi Q7. And since you'll power the ProtoDAC with UcPure (5V), it will be even better. I am looking forward to your impressions, as soon as you've received all the parts. But why didn't you place the order from Audiophonics? You would have received the parts within a 2-3 days.
By the way, aren't you using an output stage for the ProtoDAC, like Ian Canada's OPA861?
I am also tempted to go for a ProtoDAC, but I would prefer to find an already prebuilt one, if possible, with the best quality parts. Living in Europe (Greece), I would rather get the ProtoDAC from within the European Union, to avoid any unnecessary hassle with the Greek customs.
Did you build the ProtoDAC yourself? If yes, what parts did you use?
By the way, aren't you using an output stage for the ProtoDAC, like Ian Canada's OPA861?
I am also tempted to go for a ProtoDAC, but I would prefer to find an already prebuilt one, if possible, with the best quality parts. Living in Europe (Greece), I would rather get the ProtoDAC from within the European Union, to avoid any unnecessary hassle with the Greek customs.
Did you build the ProtoDAC yourself? If yes, what parts did you use?
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@pkonstantinidis, I have already the Ian's parts I mentioned above. I ordered directly from Ian as he managed a group buying in last December and offered to consumers % off. (https://www.diyaudio.com/community/...and-s-pdif-fifo-kit-group-buy.207438/page-265). There is no taxes between Canada and Europe. So much more interesting than Audiophonics. 2 days to arrive in France ; 10 days waiting at Charles De Gaulle airport (thank you French customs...). Packaged so well by Ian.
"By the way, aren't you using an output stage for the ProtoDAC, like Ian Canada's OPA861?"
I did it like Gaby show us.
"And since you'll power the ProtoDAC with UcPure (5V), it will be even better."
Right now, ProtoDAC powered by PurePi 5V ultracapacitors (GPIO extension pins 2 and 4 cut) . So, your advice leads me to think that PurePI 5V ultracapacitors must power RPI, and UCPure must charge 3000F ultracapacitors to power ProtoDAC. Am I right ?
There is another option : UcPure charging 3000F ultracapacitors to power Q7 and ProtoDAC powered by PurePi 5V ultracapacitors (thank you Mark for your advice). Maybe, you have an idea ?
"I am also tempted to go for a ProtoDAC, but I would prefer to find an already prebuilt one, if possible, with the best quality parts. Living in Europe (Greece), I would rather get the ProtoDAC from within the European Union, to avoid any unnecessary hassle with the Greek customs."
I have seen that Mark gave a link to Holland. It seems pretty well.
I have assembled it by myself from Mark's kit (USA).
"By the way, aren't you using an output stage for the ProtoDAC, like Ian Canada's OPA861?"
I did it like Gaby show us.
"And since you'll power the ProtoDAC with UcPure (5V), it will be even better."
Right now, ProtoDAC powered by PurePi 5V ultracapacitors (GPIO extension pins 2 and 4 cut) . So, your advice leads me to think that PurePI 5V ultracapacitors must power RPI, and UCPure must charge 3000F ultracapacitors to power ProtoDAC. Am I right ?
There is another option : UcPure charging 3000F ultracapacitors to power Q7 and ProtoDAC powered by PurePi 5V ultracapacitors (thank you Mark for your advice). Maybe, you have an idea ?
"I am also tempted to go for a ProtoDAC, but I would prefer to find an already prebuilt one, if possible, with the best quality parts. Living in Europe (Greece), I would rather get the ProtoDAC from within the European Union, to avoid any unnecessary hassle with the Greek customs."
I have seen that Mark gave a link to Holland. It seems pretty well.
I have assembled it by myself from Mark's kit (USA).
Attachments
The ProtoDAC kit uses Vishay Audio Resistors, which are bulk metal foil, Z-foil in 420R, Texas Components TX2575, for purely passive I/V. These are made to order. Charcroft is a manufacturer in the EU. HiFiCollective stocks Z-foil by Charcroft. Parts Connexion in Canada also stocks VAR. The TX2575 are expensive resistors, but definitely worth the cost in this application. Much better than the finest metal film resistors. These are the most difficult parts to source.
The output coupling capacitors are WIMA MKP 4. These are competent, but certainly could be improved upon. See Humble Homemade HiFi cap test . Keep space restrictions in mind. No capacitor is perfectly transparent. If you can verify that the next component (for example, preamp) in your system has input DC blocking caps, you could substitute a wire for the cap. DC voltage output is about 2V.
I selected Panasonic FR-A (EEU-FR1A102L) power supply decoupling capacitors after listening to many different capacitors.
This is a great first DIY build. Very easy.
See information on the Moode Audio website.
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Usually, switched attenuators don't have any blocking capacitors. It's not a good idea to run DC current through the resistors in the attenuator. You could take a quick look inside, and check to be sure. Follow the path from the input jack to the attenuator. If DC current is allowed to pass, you will get popping sounds with level changes. Not good.
Max, I have a very similar setup to yours, can you post a photo showing the wiring side of your setup? (opposite side from the USB A ports on the pi)
