I recently swapped the transformer output stage with OPA861 and am very happy with the results. I am using a pair of Salas Ultrabib shunts for power. The sound is maybe a bit more forceful/impactful but retaining the creamy sound quality of the transformers while still being detailed with separation.
Ian, what other resistors have you tried with the output stage? I am curious if something like z foils might make a difference.
I also added sheildpi at the same time. This is a noticeable improvement to rpi4 only. When switching back to Amanero as a source instead of rpi4 I think rpi4 + shieldpi might sound more clear but again tough to tell definitively and being able to use USB out for all coMother sound output is a big advantage.
My plan is to use the transformer output stage as a separate standalone usb powered Dac with rpi4, purepi and receiverpi to output toslink from a tv when streaming from Apple TV and streaming Volumio to main speaker system. I may convert to hdmpipro as a transport to feed an R2R Dac as well as Ian is doing.
Ian, what other resistors have you tried with the output stage? I am curious if something like z foils might make a difference.
I also added sheildpi at the same time. This is a noticeable improvement to rpi4 only. When switching back to Amanero as a source instead of rpi4 I think rpi4 + shieldpi might sound more clear but again tough to tell definitively and being able to use USB out for all coMother sound output is a big advantage.
My plan is to use the transformer output stage as a separate standalone usb powered Dac with rpi4, purepi and receiverpi to output toslink from a tv when streaming from Apple TV and streaming Volumio to main speaker system. I may convert to hdmpipro as a transport to feed an R2R Dac as well as Ian is doing.
Apologies if this isn't the right thread to raise this, but this seems to be where the active iancanada folks hang out. 
I've got a Allo DigiOne Signature that I'd like to add a rechargeable "clean" battery supply to. After reading here and on iancanada's Github, it seems like the LiFePO Mini 6.6v would fit the bill and stack nicely atop the Allo HAT. The DigiOne Sig asks for 5-8v, 100mAh. Any reasons not to try the LiFeP0 Mini 6.6.v here? Anyone else out there running an Allo DigiOne Sig that way?
Any thoughts on whether other iancanada board would be an interesting upgrade path? The DigiOneSig has it's own reclocker, I believe, so not sure any iancanada reclockers make sense. Also, the Pi gets power through the Allo board, so PurePi also seems inadvisable?
Thanks in advance for any advice.
I've got a Allo DigiOne Signature that I'd like to add a rechargeable "clean" battery supply to. After reading here and on iancanada's Github, it seems like the LiFePO Mini 6.6v would fit the bill and stack nicely atop the Allo HAT. The DigiOne Sig asks for 5-8v, 100mAh. Any reasons not to try the LiFeP0 Mini 6.6.v here? Anyone else out there running an Allo DigiOne Sig that way?
Any thoughts on whether other iancanada board would be an interesting upgrade path? The DigiOneSig has it's own reclocker, I believe, so not sure any iancanada reclockers make sense. Also, the Pi gets power through the Allo board, so PurePi also seems inadvisable?
Thanks in advance for any advice.
This might be a fun read. It's a bit dated, but at one time I was considering Car Battery for power. I forgot all about until I had a flashback this week. Many thanks for making it straightforward for LiFePO4 and UltraCaps. Car Battery is anything but straightforward.
http://www.mother-of-tone.com/current.htm
My wish is to move on from Raspberry Pi to a x86_64 platform in 3 years, but I don't think the x86_64 software is mature enough yet for GPIO.
I considered a Turning Pi2 which allows four Compute Module 4, but that's not going to work out. You can't scale CPU power with Raspberry Pi for Audio purposes.
So I want to UltraCap a Motherboard (9V - 24V) with a powerful Intel CPU and my own Audiophile RAM (Left side of Motherboard). And on this platform, I only trust PCI-E (Right side of Motherboard). So if there is someway to add Audio HATs on a PCI-E board that would be nice. But then you have that GPIO software bottleneck even if the hardware works out.
I'll likely try this with PCI-E USB with USB optical cable one day. It would just be nice if somehow you can SinePi a PCI-E solution for Andrea's Clock or Clock-Roll on PCI-E without the legacy Raspberry Pi interfaces. That way there may not be a need to involve GPIO at all, so the software doesn't need to catch up.
I already run low latency realtime on both Raspberry Pi and x86_64, so I have optimised pre-compiled kernels already. Just the additional CPU Power and Audiophile RAM would be fun.
Something like this. I believe U1 is the clock:
Toslink would be nice, but I have a USB optical cable so I'm unsure ATM. I never tried re-clocking USB yet.
I considered a Turning Pi2 which allows four Compute Module 4, but that's not going to work out. You can't scale CPU power with Raspberry Pi for Audio purposes.
So I want to UltraCap a Motherboard (9V - 24V) with a powerful Intel CPU and my own Audiophile RAM (Left side of Motherboard). And on this platform, I only trust PCI-E (Right side of Motherboard). So if there is someway to add Audio HATs on a PCI-E board that would be nice. But then you have that GPIO software bottleneck even if the hardware works out.
I'll likely try this with PCI-E USB with USB optical cable one day. It would just be nice if somehow you can SinePi a PCI-E solution for Andrea's Clock or Clock-Roll on PCI-E without the legacy Raspberry Pi interfaces. That way there may not be a need to involve GPIO at all, so the software doesn't need to catch up.
I already run low latency realtime on both Raspberry Pi and x86_64, so I have optimised pre-compiled kernels already. Just the additional CPU Power and Audiophile RAM would be fun.
Something like this. I believe U1 is the clock:
Toslink would be nice, but I have a USB optical cable so I'm unsure ATM. I never tried re-clocking USB yet.
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Hi.
@iancanada
Not sure if this is the right place for my Qs.
Just got my hands on a ShieldPi Pro. I know I am late to the party.
I've btw been using my own OSCON buffer/filter for years - attached directly to GPIO. I wanted to see if things
get better with the Shieldpi.
I am attaching the Shieldpi with a 90° angle adapter for better PI cooling.
Now. I tried to understand the related ShieldPi Pro document.
1.
What I don't see is a recommendation where to insert the 5V power supply. What's the prefered 5V input socket?
I run a PI with a Katana attached to it - just to mention it.
Wouldn't it be nice to have a central 5V input socket also on the ShieldPi? Ground, 5V all attached in one spot!?!?
2.
The external Power On/OFF Button. How is that supposed to work? Just a short? Doing what?
3.
How about the auxiliary GPIO header. Isn't that acting a bit like like an antenna, without being terminated/covered ?
Any advice to understand and to squeeze most out of the board is appreciated.
@iancanada
Not sure if this is the right place for my Qs.
Just got my hands on a ShieldPi Pro. I know I am late to the party.
I've btw been using my own OSCON buffer/filter for years - attached directly to GPIO. I wanted to see if things
get better with the Shieldpi.
I am attaching the Shieldpi with a 90° angle adapter for better PI cooling.
Now. I tried to understand the related ShieldPi Pro document.
1.
What I don't see is a recommendation where to insert the 5V power supply. What's the prefered 5V input socket?
I run a PI with a Katana attached to it - just to mention it.
Wouldn't it be nice to have a central 5V input socket also on the ShieldPi? Ground, 5V all attached in one spot!?!?
2.
The external Power On/OFF Button. How is that supposed to work? Just a short? Doing what?
3.
How about the auxiliary GPIO header. Isn't that acting a bit like like an antenna, without being terminated/covered ?
Any advice to understand and to squeeze most out of the board is appreciated.
1.
In my opinion the 5V goes through the GPIO header,It is not necessary to have a other 5V connector.
'I am attaching the Shieldpi with a 90° angle adapter for better PI cooling'
I don't think it's a good idea,the ShieldPi Pro must be more effective when placed above the RPI,But I could be wrong,IAN ?
are you satisfied with the result of the ShieldPi Pro?
In my opinion the 5V goes through the GPIO header,It is not necessary to have a other 5V connector.
'I am attaching the Shieldpi with a 90° angle adapter for better PI cooling'
I don't think it's a good idea,the ShieldPi Pro must be more effective when placed above the RPI,But I could be wrong,IAN ?
are you satisfied with the result of the ShieldPi Pro?
If you don't use IANs other stuff, you have to feed 5V through the RPI-USB-C.
That's not really nice.
If the ShieldPi is supposed to be a kind of starground-point it'd be best to
have all the power input at that place too.
Since the auxiliary header is open, perhaps it'd be an option to feed 5V
through that header. I am not such a big fan of feeding 5V straight through
the header pins though.
Having a nice screw-terminal to feed 5V to the ShieldPi AND the PI would have
been a very convenient option. That's all I am saying.
Let's talk about the "shield" in ShieldPi. I consider the actual shielding option
pretty inefficient. To me it's almost useless. If 70% of the surface is unshielded,
what's such a mini-shield supposed to do !?!?
The "shield" shields at least the power rails on the ShieldPi board (hopefully).
That's the good part.
To me most important are the rail-buffer and the rail-filter options.
The buffer (and filter?) makes a difference even if you feed the
RPI with a UCPure setup.
And again. The shield keeps the heat on the CPU. As all HATs would do.
The MK2 is a bit better in that regard, still no use for me.
A 90° angle header, turns all HATs much further away from the RPi and
allows an extremely efficient cooling. That way you could also add your own
shield-extension that does what a shield should do.
Anhow. It is what it is.
I'd still appreciate if Ian could answer my earlier Qs and
I'd also appreciate if the product documentation could be updated accordingly.
Thx
That's not really nice.
If the ShieldPi is supposed to be a kind of starground-point it'd be best to
have all the power input at that place too.
Since the auxiliary header is open, perhaps it'd be an option to feed 5V
through that header. I am not such a big fan of feeding 5V straight through
the header pins though.
Having a nice screw-terminal to feed 5V to the ShieldPi AND the PI would have
been a very convenient option. That's all I am saying.
Let's talk about the "shield" in ShieldPi. I consider the actual shielding option
pretty inefficient. To me it's almost useless. If 70% of the surface is unshielded,
what's such a mini-shield supposed to do !?!?
The "shield" shields at least the power rails on the ShieldPi board (hopefully).
That's the good part.
To me most important are the rail-buffer and the rail-filter options.
The buffer (and filter?) makes a difference even if you feed the
RPI with a UCPure setup.
And again. The shield keeps the heat on the CPU. As all HATs would do.
The MK2 is a bit better in that regard, still no use for me.
A 90° angle header, turns all HATs much further away from the RPi and
allows an extremely efficient cooling. That way you could also add your own
shield-extension that does what a shield should do.
Anhow. It is what it is.
I'd still appreciate if Ian could answer my earlier Qs and
I'd also appreciate if the product documentation could be updated accordingly.
Thx
Hi, Can I use this Output Transformer on Headphone Amplifier System ?Transformer I/V party, listening test results
I’m working on this comparison test for a while. I'd like to share my results here with you. Sorry for the delay. I could be wrong. Just for you to reference. I picked up these three because they have the same configuration. I could have more reports for others down the road.
#3 eBay 600:10K audio transformer
I bought this pair of 600:10K transformers off eBay. They are not expensive but look pretty decent. I didn’t expect too much from them. However the real listening test did give me some surprise. They have all the sound signature of a typical transformer I/v stage. Nature, analog, peaceful and without any additional flavor. I would stack with them if didn’t experience the other two. I ran them at my LL1544A transformer I/V PCB with same schematic and same configuration. The only thing is that the footprints don’t fit very well. If I have chance to design the transformer I/V II PCB I’d like to make it compatible with them.
If you have never tried the transformer I/V, I would highly recommend this one as starting point.
#2 LL1544A
My transformer I/V PCB was originally designed for them. I have been using them for a long time before I had the BisesiK transformers. I have to say I’m very familiar with the sound. For me, it’s my first transformer I/V that could touch the ‘high end’ in my heart. Besides all the sound signature of a typical transformer I/V stage, LL1544A has higher sound density and plays music more dynamically. Especially it has a very beautiful mid-high range which makes the music a little sweet feeling. I enjoy listening to my favorite vocal jazz with them very much. I could listen to music for a long time almost forgot I was doing comparison test.
LL1544A I/V stage will suitable for all kinds of music and all kinds of system
#1 Bisesik transformers
I must put them in the first position though they are not the kind of transformer I/V that you can fall in love with them immediately at the first time you use them. However, after two weeks of run in, I’m getting in love with them more and more and for now I almost can’t live without them.
If I had only one word to express them I would use the word ‘perfect’. They are not good at certain frequency range but good at all frequency ranges. The low rang could be extended much lower (why they are so big?) than other transformers which feature could be looked upon as common weakness of all transformer I/V stages. So I’m considering maybe I could degrade my speakers from B&W802 to B&W803 because of that. Just kidding! They sound not only with higher density at full frequency range but also play music much vividly. The bigger stage and bigger band you are listening, the stronger you feel about that. If I had another word to use, I would use the word ‘musical’. They play all music with emotion. You can feel the whole atmosphere surrounding you. When I’m listening violin with them, I almost couldn’t help cry. The Bisesik transformers are suitable for all kinds of music. But if you really like the classical music, my advice is that sticks with this one no need to consider any others.
I had a pair of Japanese Oyaide AR-910 pure silver XLR cables. They are pretty decent but I always feel the high range sounds a bit strange when I use them with other I/V stage. However, with Bisesik transformer, everything becomes correct and precision. When I use this configuration listening the sound track of film Pirates of the Caribbean, The Curse of the Black Pearl (I like the big band), I was almost shocked. The huge band and the whole stage were surrounding me and I can hear each hidden details. All instruments are playing vividly together at their positing. I can feel each of them. This feeling could be even better than I was in a real theater.
Though I put Bisesik transformers in the first position, but I wouldn’t recommend them for you if your system is not good enough. The better system you have, the more advantage of these transformers you can feel.
My system for listening test
Transformer I/V for test
1. ES9038Q2M DM DAC HAT (with three independent 3.3V voltage rails)
2. ShiledPi
3. FifpPi with Pulsar 90.xxx MHz clock
4. ReceiverPi
5. RPi3
6. LiefPO4 power supply with ultra capacitor conditioners at both 5V RPi rail and the 3.3V FifoPi clock rail.
The rest of the system
1. B&W 802 D2 speakers
2. PASS XA160.5 amplifiers
3. PASS XP-10 per-amplifiers
TransformerIvParty by Ian, on Flickr
BW802PASSXA160.5 by Ian, on Flickr
Ian
Hi All,
Total noob here. Will the below work as a standalone USB to i2s converter if I add an external power supply? Not currently working with my holo spring DAC. Had tried to use the 3.3v from the amanero board but I don't think it provides enough current. I do have a PS Audio DAC I could try that I believe sends power over the hdmi cable, unlike the holo.
Just trying to start cheap with the parts I have laying around, and then possibly upgrade once I have something working. The coax breakout wires were hooked up with red to mclk and black to gnd on the amanero 20 pin header. Hopefully I have the switches on the hdmiPi in the right positions to receive i2s signals (minus mclk) from the gpio pins.
Thanks, and I'm excited to be starting this journey!
Total noob here. Will the below work as a standalone USB to i2s converter if I add an external power supply? Not currently working with my holo spring DAC. Had tried to use the 3.3v from the amanero board but I don't think it provides enough current. I do have a PS Audio DAC I could try that I believe sends power over the hdmi cable, unlike the holo.
Just trying to start cheap with the parts I have laying around, and then possibly upgrade once I have something working. The coax breakout wires were hooked up with red to mclk and black to gnd on the amanero 20 pin header. Hopefully I have the switches on the hdmiPi in the right positions to receive i2s signals (minus mclk) from the gpio pins.
Thanks, and I'm excited to be starting this journey!
Hello; I have a question about the 2x 5V (1x-5/1x+5)power supply of the OPA861 fully Balanced Zero Feedback I/V Stage.
1. could I use 2x UcPi board with 2x UCCONDITIONER 5V ?
https://www.audiophonics.fr/en/powe...er-supply-board-for-raspberry-pi-p-16717.html
2. or would 2x LIFEPO4 MINI 6.6 V with 2x UCCONDITIONER 5V also work?
https://www.audiophonics.fr/en/batt...-battery-power-supply-module-66v-p-15832.html
I would like to connect it like this, only without the toroidal transformer and Linear Pi Dual..
1. could I use 2x UcPi board with 2x UCCONDITIONER 5V ?
https://www.audiophonics.fr/en/powe...er-supply-board-for-raspberry-pi-p-16717.html
2. or would 2x LIFEPO4 MINI 6.6 V with 2x UCCONDITIONER 5V also work?
https://www.audiophonics.fr/en/batt...-battery-power-supply-module-66v-p-15832.html
I would like to connect it like this, only without the toroidal transformer and Linear Pi Dual..
Attachments
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Hi Ian,
Please ignore my request for USB future anything. I going to give up on USB Reclocking because there is just no value. I came to this conclusion after configuring my LiFePO4 MKIII to use All ten batteries to test power my Intel NUC PC.
I got a little under 3 hours of use. It's not enough to justify a Passive Powered USB Reclocking setup since I only use Audio gear that is off of Mains. I could scale three UcPure/UcBalancer, but it has crossed the inflection point of value.
I have arguably the World's Best Toslink Chain with Andrea's SOTA CLK @5.6448 MHz/TransportPi AES and arguably the World's Best Passive Power Supplies with the UcPure/UcBalancer so the USB project would have to provide a good amount of value to pursue. It doesn't, it may even be a downgrade from my current sunk cost setup.
So I'll keep an eye out for the USB Input on the ReceiverPi in 2025 if one day I go RPI-less. For now, I'm a very happy camper as my whole chain is off Mains via Passive Power. I was distracted by USB options, but in reality what I have built is really all I need. Money better used for Music or UcPure/UcBalancer upgrades.
Please ignore my request for USB future anything. I going to give up on USB Reclocking because there is just no value. I came to this conclusion after configuring my LiFePO4 MKIII to use All ten batteries to test power my Intel NUC PC.
I got a little under 3 hours of use. It's not enough to justify a Passive Powered USB Reclocking setup since I only use Audio gear that is off of Mains. I could scale three UcPure/UcBalancer, but it has crossed the inflection point of value.
- PCI-E USB Reclocking boards cost around $1500
- The Industrial Motherboard plus Audiophile RAM cost around $1800
- 3 UcPure/UcBalancer will add up too with 18 Eatons needed in total.
I have arguably the World's Best Toslink Chain with Andrea's SOTA CLK @5.6448 MHz/TransportPi AES and arguably the World's Best Passive Power Supplies with the UcPure/UcBalancer so the USB project would have to provide a good amount of value to pursue. It doesn't, it may even be a downgrade from my current sunk cost setup.
So I'll keep an eye out for the USB Input on the ReceiverPi in 2025 if one day I go RPI-less. For now, I'm a very happy camper as my whole chain is off Mains via Passive Power. I was distracted by USB options, but in reality what I have built is really all I need. Money better used for Music or UcPure/UcBalancer upgrades.
@iancanada
What is the output impedance of your I/V opa861? In your opinion, is it low enough to drive 2k balanced load?
What is the output impedance of your I/V opa861? In your opinion, is it low enough to drive 2k balanced load?
Hello,
He told me average is 60 mA so i decided to ask Guido Tent for a 5 volt shunt that can deliver 100 mA. This little circuit board can be mounted where the input terminal is for the five volt so where the supply needs to be. I think that is as important as a good supply. Long cables only cause trouble. Greetings Eduard
I'm close to do the same move as yours, as my main goal is not a dac, but a roon server. And that is the ONE thing rasp4 can't do, sadly.
But I do not want to give up on the PSU side of the thing, and there, like you, I'm exploring lifePIO4 MKIII (one or two) as a viable option to correctly power up a thin mini itx mobo with an intel cpu that could be passively cooled. That would make a perfect roon server, with clean DC power. No clue if it's doable though, my knowlegde with this is limited.
not sure if anyone still reads this thread. I'm wanting to slowly build a streamer for my pi4 and was thinking of going with the transportpi digi. Now the question is can the digi be connected to a fifo at a later date? can the clocks be removed or bypassed? otherwise i'll have to go with a normal transportpi and the fifo
@lad73
Here is the comparison of TransportPi Digi and other TransportPi solutions, just hope it helps
https://github.com/iancanada/DocumentDownload/blob/master/TransportPi/TransportPiComparison.pdf
Ian
Here is the comparison of TransportPi Digi and other TransportPi solutions, just hope it helps
https://github.com/iancanada/DocumentDownload/blob/master/TransportPi/TransportPiComparison.pdf
Ian
hi, Ian thanks for your reply. I have read that document but there is no mention of being able to use the fifo with the digi. Looks like I'll have to go with the normal transport and fifo. I was hoping to use the digi then sell it and upgrade to the aes transport with the fifo at a later date.
Hello. I have lots of staff from Ian. My latest is receiverddc input board. Im building dacnad want to have some inputs. Dac have one big oled screan nad dont want to add next. Problem is with manual input select J8. Receiverddc manual is not clear in this part. By shorting pi 2 with pins 1,3,5 i can chouse hdmi,rpi, usb and coaxial. But how to activade A optical? Very thanks for help.
