I started here.
https://hifiduino.wordpress.com/introduction-and-guide-to-hifiduino/
For my AKM build I only use a £5 Arduino, no display, encoder, remote etc. to basically write the values I want into each register.
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Don't think this is rated for 7.2V but best check the datasheet.
https://www.akm.com/akm/en/file/datasheet/AK4497EQ.pdf
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Unlike the AK4490, the AK4497 datasheet doesn't specifically mention that output voltage is dependent on the input voltage. Would probably be best just to go with the usual 5V.
EDIT : Did a double check, my mistake, looks like output voltage is still dependent on the input voltage. Given that the max recommended operating voltage is 5.25V tho, there might be only minimal gain in cranking up the voltage, unlike AK4490's max voltage input of 7.2V
EDIT : Did a double check, my mistake, looks like output voltage is still dependent on the input voltage. Given that the max recommended operating voltage is 5.25V tho, there might be only minimal gain in cranking up the voltage, unlike AK4490's max voltage input of 7.2V
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Hi guys,
I too am trying my luck at an AK4490 DAC. I have a basic design down and am waiting on prototype PCBs.
I see that many of you are using Arduino UNOs to program the chip.
You do realize that you are using 5V TTL logic to interface to a 3.3V part, right?
From what I am reading the 4490 seems to be tolerant to the 5V of the UNO, but I wouldn't keep doing that for long.. Level shifters are a dime a dozen.
Better yet, I would go for an I2C isolator.. That way I would do both galvanic isolation and level shifting with one part.
I too am trying my luck at an AK4490 DAC. I have a basic design down and am waiting on prototype PCBs.
I see that many of you are using Arduino UNOs to program the chip.
You do realize that you are using 5V TTL logic to interface to a 3.3V part, right?
From what I am reading the 4490 seems to be tolerant to the 5V of the UNO, but I wouldn't keep doing that for long.. Level shifters are a dime a dozen.
Better yet, I would go for an I2C isolator.. That way I would do both galvanic isolation and level shifting with one part.
Have had no issues with applying 5V I2C to many 3.3V DAC chips including AK4490 and ES9018S, all working fine after many years of use. YMMV
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Dimdim
we are also starting design on a 4490 for RPI. I almost have half a mind to open the design to the community.
we are also starting design on a 4490 for RPI. I almost have half a mind to open the design to the community.
I think that an ak4490-based DAC would be a great match to an RPi & Kali combo and such a community-designed DAC would be at the very least an interesting implementation.
The only problem with a HAT sized ak4490-DAC would be the constraints of the HAT size. It would mean that a cost-no-object design would basically be out of the question. On the other hand, not everyone would desire a cost-no-object design.
The only problem with a HAT sized ak4490-DAC would be the constraints of the HAT size. It would mean that a cost-no-object design would basically be out of the question. On the other hand, not everyone would desire a cost-no-object design.
Ok we can open most of the design. (not gerber)
I also think that we should bring only one power supply to the board and generate everything from there..
Choices:
1. Should it be master or slave
2. How many voltages are needed..and what value (important)
3. Summing circuit..(choice of opamp and voltages)
I also think that we should bring only one power supply to the board and generate everything from there..
Choices:
1. Should it be master or slave
2. How many voltages are needed..and what value (important)
3. Summing circuit..(choice of opamp and voltages)
And this
http://terratechnos.com/products/terraberrydac/
Enviado do meu SM-J500F através de Tapatalk
http://terratechnos.com/products/terraberrydac/
Enviado do meu SM-J500F através de Tapatalk
Yeap I am aware of this design...I was thinking something along those lines.
I have a dual-mono AK4497 DAC kit on its way to me;
AK4497DM DAC??
(I use Google Translate)
I will need to derive a single-ended signal from the DAC outputs (voltage output so no I/V required). I have previously had good results using a Broskie BCF on the outputs of a AK4490 DAC (single) and that remains an option (though the BCF has been out of stock for a long time)
However, as this new DAC is dual-mono it is a slightly different scenario as the DAC outputs need to be summed, here's the relevant datasheet schematic;
Instead of using the 100uF cap and 10K/44R resistors, I'm wondering if I can simply connect the relevant DAC outputs together (to sum them) and feed the differential signals into a suitable transformer to derive the SE signal (I'm assuming the roll-off of the transformer will double up with LP filter duties too). Even better would be to use my Silk TVCs as the transformer.
The plan is to pass the SE signal to a 4P1L tube buffer stage.
Thoughts/comments?
Cheers
Ray
AK4497DM DAC??
(I use Google Translate)
I will need to derive a single-ended signal from the DAC outputs (voltage output so no I/V required). I have previously had good results using a Broskie BCF on the outputs of a AK4490 DAC (single) and that remains an option (though the BCF has been out of stock for a long time)
However, as this new DAC is dual-mono it is a slightly different scenario as the DAC outputs need to be summed, here's the relevant datasheet schematic;
An externally hosted image should be here but it was not working when we last tested it.
Instead of using the 100uF cap and 10K/44R resistors, I'm wondering if I can simply connect the relevant DAC outputs together (to sum them) and feed the differential signals into a suitable transformer to derive the SE signal (I'm assuming the roll-off of the transformer will double up with LP filter duties too). Even better would be to use my Silk TVCs as the transformer.
The plan is to pass the SE signal to a 4P1L tube buffer stage.
Thoughts/comments?
Cheers
Ray
Those resistors and caps *are* summing the outputs. Each summed output is fed to an LPF - so yes, you can use a transformer instead of the two opamps. I would not eliminate any of those components. Ensure your transformer Rdc does not form a high pass filter with the capacitor and cut your low bass off, you can increase the cap without penalty.
You can also use only one polarity of output, this will change the characteristics of the sound to include more second order HD which theoretically degrades THD. You could also try dual primary windings, with the transformer doing the summing. Experimentation is key to getting what you want.
The primary winding will be fed by the two junctions of the 44 ohm resistors, that are currently connected to the opamp + inputs (the 22 ohm resistors can be ignored).
You can also use only one polarity of output, this will change the characteristics of the sound to include more second order HD which theoretically degrades THD. You could also try dual primary windings, with the transformer doing the summing. Experimentation is key to getting what you want.
The primary winding will be fed by the two junctions of the 44 ohm resistors, that are currently connected to the opamp + inputs (the 22 ohm resistors can be ignored).
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