Hey Fellas,
I have also confirmed Miro’s AD1862 NOS Dac board is a sweet sounding success!! The music sounds very good right out of the box. I don’t even have the MSB adjustment components installed. I will have to try a few of the I/V solutions you all have been talking about to maximize my listening enjoyment. IMO, this board can be the foundation for a full featured killer DAC 😀
Thanks for sharing this project Miro 🙂
Cheers,
Vunce
I have also confirmed Miro’s AD1862 NOS Dac board is a sweet sounding success!! The music sounds very good right out of the box. I don’t even have the MSB adjustment components installed. I will have to try a few of the I/V solutions you all have been talking about to maximize my listening enjoyment. IMO, this board can be the foundation for a full featured killer DAC 😀
Thanks for sharing this project Miro 🙂
Cheers,
Vunce
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Vunce, thanks for your confirmation! I'm glad we managed to give life to this "forgotten" DAC. This DAC is definitely the perfect core for a killer DAC 😀 That's for sure.
The long journey remains for "the best" I/V. I'm afraid that a final I/V doesn't exist yet and people always come up with something new, from a tube through a transformer to various solid-states 😀 This modular form has an advantage that something new can be always easily tested at a relatively cheap price 🙂
The long journey remains for "the best" I/V. I'm afraid that a final I/V doesn't exist yet and people always come up with something new, from a tube through a transformer to various solid-states 😀 This modular form has an advantage that something new can be always easily tested at a relatively cheap price 🙂
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I agree Miro, listening to the chatting today started to make my head spin. So many different ways to perform I/V conversion!!! Where to start first 😕
I don’t think this project has an end, but as the tweaking progresses, it will continue to get better with time like a fine wine.🙂
I don’t think this project has an end, but as the tweaking progresses, it will continue to get better with time like a fine wine.🙂
Nice work, how are you planning to do the MSB adjustment?
I read someone used a -60db tone and trimmed to reduce audible noise with their amp at high volume.
I read someone used a -60db tone and trimmed to reduce audible noise with their amp at high volume.
@laserscrape,
I don’t know yet?
Does anyone have a good solution for an SPDIF to I2S converter and switching capability to add input options to this board?
I don’t know yet?
Does anyone have a good solution for an SPDIF to I2S converter and switching capability to add input options to this board?
CS8416 has multiple selectable inputs for SPDIF and one I2S output, hardware mode for selectable pins
5534 is not so bad 😀 Be sure to get the LM6171 from a trusted source.
i think ok, its from mouser.
What is the difference between the LM6171AI and BI versions?
miro: the difference between LM6171AI and LM6171BI is very small, only in a few mV offset (better in AI), the sound will be the same
AI has slightly better parameters, but not so significant, it is like BI has 6mV offset and AI has 3mV offset 😀 it is not worth to bother with this difference, take what is cheaper or stocked 😀
Thanks for the recommendations Miro and Chi0001 🙂
I’m going to add a few of the mentioned opamps to my Mouser list.
I have Tantalum and low esr polymer caps to experiment with.
Also, R8 & R9 have 1K4 resistors currently installed, I will bump them up to 2k4.
I’m going to add a few of the mentioned opamps to my Mouser list.
I have Tantalum and low esr polymer caps to experiment with.
Also, R8 & R9 have 1K4 resistors currently installed, I will bump them up to 2k4.
ADA4898-1 opamp is also good if you form a mouser list 😀 it is only in smd package, so an adapter is needed
you can bump and set the output voltage for your setup, it is fine
you can bump and set the output voltage for your setup, it is fine
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Here is 1k tone, 96kHz sample rate and roughly -60db, for MSB adjustment.
the tone is louder than expected, there should some nice improvements to be got from trimming.
Modern realtek motherboard sound chip's line-in perform quite well as it turns out , this is what Im gonna try using for it.
Here is 1k tone, 96kHz sample rate and roughly -60db, for MSB adjustment.
the tone is louder than expected, there should some nice improvements to be got from trimming.
Modern realtek motherboard sound chip's line-in perform quite well as it turns out , this is what Im gonna try using for it.
Here is a measurement through motherboard line in of -60db tone from untrimmed Ad1862 with opa1612 IV (Iv resistor is low in value, 700 ohm or so) :
THD jumps around from 1-1.5%... but is that accurate? why are their no visible harmonics above the noise?
I think noise floor of ADC will be effecting the accuracy of THD+N but I dont how much noise will influence the accuracy THD only measurements
THD jumps around from 1-1.5%... but is that accurate? why are their no visible harmonics above the noise?
I think noise floor of ADC will be effecting the accuracy of THD+N but I dont how much noise will influence the accuracy THD only measurements
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did you generate the -60db tone here?
Custom Sine Tones | Audio Test File Generator
or with audacity? is it possible to generate 20bits sine?
what happened when you turned the potentiometer?
although it is NOS without digital filters, try it with a lower frequency 100Hz? (the sinewave is stairs like, and the lower frequency is = the more bits is used = the cleaner sine 😀)
Custom Sine Tones | Audio Test File Generator
or with audacity? is it possible to generate 20bits sine?
what happened when you turned the potentiometer?
although it is NOS without digital filters, try it with a lower frequency 100Hz? (the sinewave is stairs like, and the lower frequency is = the more bits is used = the cleaner sine 😀)
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It was made in audacity.
which potentiometer do you mean? there are none currently, its just straight from IV.
I am not sure about 20 bit, I have only seen this option in HQ Player a long time ago and I think recall it refusing to start playback with an XMOS I2S interface. you can contain 20 bit data in 24 bit file though, not sure how the AD1862+I2S logic would handle that.
that file is 96kHz to give cleaner sines at higher frequency but I think you are right, 192kHz would be better since the old filter chips ran at 16x oversampling.
which potentiometer do you mean? there are none currently, its just straight from IV.
I am not sure about 20 bit, I have only seen this option in HQ Player a long time ago and I think recall it refusing to start playback with an XMOS I2S interface. you can contain 20 bit data in 24 bit file though, not sure how the AD1862+I2S logic would handle that.
that file is 96kHz to give cleaner sines at higher frequency but I think you are right, 192kHz would be better since the old filter chips ran at 16x oversampling.
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