At a minimum, I think Yarra 2 should have both SE and balanced outputs. With the addition of 2-balanced inputs and 2-SE inputs. This will give the pre a more versatile appeal - IMO.
It would be nice to have the same modular advantages that the original Yarra has, for DAC and Bluetooth, etc. - but I'm not sure how modular it could be. I have numerous RaspPis and DAC HATs that I put together and use as streaming device end-points for roon. My main system DAC (pic below), and supporting hardware would not conveniently fit into a Yarra case sadly.
Now, if you could provide space and back panel cutouts for a 'drop-in' RPi footprint, with associated clean power for a DAC HAT, that would excite me. The user could then supply the RPi and their favorite HAT with all the hookups ready to go. But I realize that may be outside the boundaries of the Yarra 2 conceptual design scope. I may be dreaming too.After spending over a year building, modding and tweaking the one pictured below, it has pretty much provided digital nirvana for me. Once I start listening I have a hard time turning it off.
I never thought a DAC could sound that good! Quality source dependent.Attachments
Hi MM,
Apologies, I’ve just checked my PM’s and it seems it didn’t send. Thanks for letting me know though.
Sure thing.
Shown illustrated below is a block diagram of my entire DAC sub-system. This system uses the IanJin RPi DAC stack of complementary products featured in DIY Audio. More can be found here. Each block is numbered, corresponding to the list below.
1 - Dual secondary 9V & 15V xformer
2 - Dual secondary 9V & 15V xformer
3 - Dual 5V LDO DIYINHK Low-Noise Regulator. One side feeds the FifoPi Utimate reclocker. The other side feeds the dual mono ES9038Q2M DAC and AVCC Twisted Pear Regulator. It also provides a clean 5V to Jan Didden's SilentSwitcher (#7).
4 - Linear PSU rectifier and filter caps feeds +- voltages to #5. (Super Reg)
5 - Dual Jung/Didden Super Regulator providing +-15V to #9 (I/V Stage of DAC stack)
6 - Regulated 5V PSU provides separate power to the RPi.
7 - Jan Didden SilentSwitcher. (under the ribbon cable) This provides 6.5V as input to; 2 NewClassD Low Noise Regulators, used for both DVCC and VCCA.
8 - The DAC stack consisting of, from bottom to top; (1) RPi, (2) FifoPi Ultimate with upgraded Crystek clocks and (3) Dual Mono ES9038Q2M DAC board with 3 off-board regulators previously mentioned.
9 - I/V Stage with upgraded Burson Audio V5i-D opamps.
Is this what you were looking for? I don't have a schematic.
Shown illustrated below is a block diagram of my entire DAC sub-system. This system uses the IanJin RPi DAC stack of complementary products featured in DIY Audio. More can be found here. Each block is numbered, corresponding to the list below.
1 - Dual secondary 9V & 15V xformer
2 - Dual secondary 9V & 15V xformer
3 - Dual 5V LDO DIYINHK Low-Noise Regulator. One side feeds the FifoPi Utimate reclocker. The other side feeds the dual mono ES9038Q2M DAC and AVCC Twisted Pear Regulator. It also provides a clean 5V to Jan Didden's SilentSwitcher (#7).
4 - Linear PSU rectifier and filter caps feeds +- voltages to #5. (Super Reg)
5 - Dual Jung/Didden Super Regulator providing +-15V to #9 (I/V Stage of DAC stack)
6 - Regulated 5V PSU provides separate power to the RPi.
7 - Jan Didden SilentSwitcher. (under the ribbon cable) This provides 6.5V as input to; 2 NewClassD Low Noise Regulators, used for both DVCC and VCCA.
8 - The DAC stack consisting of, from bottom to top; (1) RPi, (2) FifoPi Ultimate with upgraded Crystek clocks and (3) Dual Mono ES9038Q2M DAC board with 3 off-board regulators previously mentioned.
9 - I/V Stage with upgraded Burson Audio V5i-D opamps.
Is this what you were looking for? I don't have a schematic.
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That is a very impressive setup Redjr. Nicely done!
Would a universal DAC PSU with a bunch of ultra low noise outputs interest you? It would have +/-5v, +/-12v, +/-15v and all powered from a single 12v trafo rectified by an LT4320. Jhofland designed one for Vunce's DAC box and it seems to be very useful. It may reduce the sheer number of PSU's you have above - although some may require higher currents.
Would a universal DAC PSU with a bunch of ultra low noise outputs interest you? It would have +/-5v, +/-12v, +/-15v and all powered from a single 12v trafo rectified by an LT4320. Jhofland designed one for Vunce's DAC box and it seems to be very useful. It may reduce the sheer number of PSU's you have above - although some may require higher currents.
Yes. That would be great, and help reduce some of my footprint. This particular project started in another thread with the modding of an Asian ES9038Q2M based board (non-RPi form factor). I learned that it (the project) was beyond my interest level (and patience) at the time. I quickly abandoned it. Around the same time, I became interested in what IanJin was offering with his FifoPi reclocker and DAC, based on the same ESS chipset. I went that route instead, and with some of what I learned about PSUs, LDOs, clocks, etc., I applied to his 'DAC Stack' (as I like to call it), and after about a year, this is what resulted. It's probably not perfect, but it ultimately lead me to adopting roon as my digital streaming service and 'manager'. So, I've effectively, drank the RPi/roon cool-aid and been having a lot of fun, with a few of your fantastic kit sets along the way as well! And did I say, "It sounds great too!"
I'm sure if I had to do it all over, a single board with all the regulators for the uber quiet and clean low-voltages DAC chips require would make it simpler. Like what Allo has produced with their USBridge Signature. They have something like 31 LDOs on that RPi transport board.
That singular PSU sounds like another good starting place for my next project. Others may be interested too. Group buy started yet for it?
Thanks JT. There is a little controller/display board for the FifoPi Reclocker that you can't see in my picture. It faces the back panel! It is designed to be mounted remotely and controlled via an Apple remote. Never taken the time to design and fix it to the front panel yet.
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Looks good. Very interested. I'd want a 3A supply for the RPi. It nominally uses 2.5A, and most RPi wall-warts supply that.
Hi Redjr,
Pretty fancy setup you’ve got there, lots of goodies packed in that chassis. Nice!!
I’m keeping it simple and going with an old school R-2R AD1862 DAC chip in NOS mode. My application doesn’t require big time current draw, the Vpower psu would not be adequate for >200mA.
But, the pcb’s are small and a pair of them can be powered from a single 12v dual secondary trafo. I’m using one of the Talema’s (12v) we use in the Yarra psu.
Pretty fancy setup you’ve got there, lots of goodies packed in that chassis. Nice!!
I’m keeping it simple and going with an old school R-2R AD1862 DAC chip in NOS mode. My application doesn’t require big time current draw, the Vpower psu would not be adequate for >200mA.
But, the pcb’s are small and a pair of them can be powered from a single 12v dual secondary trafo. I’m using one of the Talema’s (12v) we use in the Yarra psu.
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Xrk, excellent stuff! My hats off to you. I too have been working on a modular preamp and we have ended up with a lot of parallel design choices- from dual mono capmx to input boards and even the use of curved traces (yes they look the best! 😁) i too am putting mine in a custom case tho mine wont be good enough for a group buy.
Have you thought about including a dc relay on the board, or even a delay network for a turn on thump? I need one on mine and cant decide how to power it because i dont wanna ruin the prestine dual mono architecture not knowing how much the relay circuit is going to affect the supply line.
Have you thought about including a dc relay on the board, or even a delay network for a turn on thump? I need one on mine and cant decide how to power it because i dont wanna ruin the prestine dual mono architecture not knowing how much the relay circuit is going to affect the supply line.
Thanks for the kind words Donovas! I have turn on delay and DC protect solid state relay for a speaker but it would work fine for a preamp. It has been measured to add no distortion to the signal. Uses 20mA and can be supplied with a single rail voltage from +18v up to +150v as it has a built in linear regulator. The relays are actuated by an optoisolator so there is very little danger of the SSR degrading your power supply. You could always pull it off before the cap Mx if you were concerned. I also have a headphone amp / preamp version of the SSR but it’s not RTR - you need to solder your own SMT parts.
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Here is thread on headphone version to gather level of interest but there was not enough to make a RTR production run. The headphone version is in stereo and uses both +/- power supply rails as it uses bipolar comparators rather than an optoisolator to check for DC offset.
RTR SSR Headphone Amplifier DC Protection Modules GB
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Here is thread on headphone version to gather level of interest but there was not enough to make a RTR production run. The headphone version is in stereo and uses both +/- power supply rails as it uses bipolar comparators rather than an optoisolator to check for DC offset.
RTR SSR Headphone Amplifier DC Protection Modules GB
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I have a new solution for converting balanced to single ended and vice versa. Can be a useful addition to the Yarra to give it flexibility of inputs/outputs. Uses SOA opamps so very neutral and transparent. Most of all, absolutely quiet with no audible self noise with audio source off.
BTSB Buffer - SE/Bal to SE/Bal Buffer GB
BTSB Buffer - SE/Bal to SE/Bal Buffer GB
Hi Folks,
If there is any interest in the new Yarra PSU with micro active bridges and low noise LDO regulators shown here:
The YARRA Preamplifier/HPA for Melbourne DB Group Buy
Please let me know. It really is the ultimate state of the art in low noise linear regulated PSUs for preamps and headphone amps.
I can revise the prototype for production if we can get some interest going. If you don’t mind working on the prototype by adding a few solder jumpers. Let me know.
If there is any interest in the new Yarra PSU with micro active bridges and low noise LDO regulators shown here:
The YARRA Preamplifier/HPA for Melbourne DB Group Buy
Please let me know. It really is the ultimate state of the art in low noise linear regulated PSUs for preamps and headphone amps.
I can revise the prototype for production if we can get some interest going. If you don’t mind working on the prototype by adding a few solder jumpers. Let me know.