Yes .. you are all right .. you helped a lot .. i thought i could get away with one PSU2 but it is not possible for my needs .
So @NIXIE62 your proposal is what i am going to follow . i will build one PSU2 for seperate analog and digital 5v using the 2x7v transformer and Jan Didden's super reg for the +-15v I/V stage with the 2x15v transformer .. thank you !
So @NIXIE62 your proposal is what i am going to follow . i will build one PSU2 for seperate analog and digital 5v using the 2x7v transformer and Jan Didden's super reg for the +-15v I/V stage with the 2x15v transformer .. thank you !
It's a practical option to use the transformers you have. Regardless of what the datasheet says, I always do separate power supplies for the digital and analog parts, at least a separate regulators. With 7+7VAC, there is no need for coolers on the regulators. You just have to pay attention to the ground loop. Since there is already common GND on PSUD2, I would lead only one thick GND wire to the DAC PCB. Maybe I'm wrong?
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Let's say PCM56, AD1856 and AD1860, and maybe some others have a digital part that works on +-5V and analog on -+12V. So with one PSUD2 (4 regulators), one 12+12V transformer and, say, an Amanero PRC clone, I will make a whole small USB DAC for little money, but it will sound almost like a big one with some good OPAs.
I think PCM63 and PCM1702 are similar in their power supply needs . they both need +-5v for digital and analog part .
How did people implement PCM63 power supplies if they used +-15v for opamps or discrete I/V stage ? i suppose they used 1 PSU2(or PSU1) pcb for +-5v and 1 PS for I/V . Another separate PS is beneficial for USB-to-I2S pcb.. so 3 power supplies and 3 transformers ..
How did people implement PCM63 power supplies if they used +-15v for opamps or discrete I/V stage ? i suppose they used 1 PSU2(or PSU1) pcb for +-5v and 1 PS for I/V . Another separate PS is beneficial for USB-to-I2S pcb.. so 3 power supplies and 3 transformers ..
It's very simple.
We use two transformers with multiple secondaries, custom made. I practice a torus transformer say 30VA on iron for 50VA, with reduced core magnetization and blind thread. One transformer is for the digital part, the other for the analog part of the device. On one PSUD2, +-5V and +-12V regulators are made for the analog part of the DAC chip and OPAs. On the second PSUD2, +-5V is made for the digital part of the DAC chip and +5V 100mA for the output part of the JLS card (and possibly another 50mA for the AK4113 card.) One PSUD2 board is cut in half and a +5V 400mA regulator is made there for the input part of the JLS card wih large cooler, which must be galvanically isolated from the rest, meaning a separate secondary and connected to GND with a 100nF capacitor (AC GND for high frequencies). Of course, it can be done differently .
You will like this combo. I used the PSU2 with +-5 and +- 12V for AD1862 and Super Reg +-15 for EUVL discrete I/V
Or CRC filters and a shunt regulator, but it is also the most ineffective way and also the most expensive, but the result justifies the investment.
For comparison, in my DAC, I have about 14W of dissipation on six shunt regulators and a couple of watts on CRC filters and three transformers, which makes up most of the DAC, and at the same time, it is quite expensive because of the discrete shunt regulators.( 24 depletion mosfet, 6 op amps,...)
In my opinion, the best choice for DAC
For comparison, in my DAC, I have about 14W of dissipation on six shunt regulators and a couple of watts on CRC filters and three transformers, which makes up most of the DAC, and at the same time, it is quite expensive because of the discrete shunt regulators.( 24 depletion mosfet, 6 op amps,...)
In my opinion, the best choice for DAC
I guess @miro1360 meant it to be some simple DAC. However, things got a little out of hand.
I used an R-core with 12V & 15V secondaries. Got it on Ebay. Looks the same as Vunce's above, just different windings.
