ProtoDAC TDA1387 X8 project

[Rio1969]

There should be no noise. You can double check your solder connections.

Will do.

[Rio1969]

It turns out that the noise was from my headphone amp. It is one that I don't normally use, it is the only one that I have with RCA inputs. I tried the Protodac with my main speaker system and there was no noise.

[v12nut]

Noise is almost always caused by a bad module.

What does that sound like? earth hum? crackle? I ask because I have an Hum and am trying to figure it out

[hifinet]

The noise from a bad module is usually an intermittent buzz. The bad module can be unusually sensitive to picking up wifi noise.

[v12nut]

The noise from a bad module is usually an intermittent buzz. The bad module can be unusually sensitive to picking up wifi noise.

Thanks, in my case its probably earth related.

[OnkelPH]

@hifinet what’s the output gain of the ProtoDAC?

[hifinet]

With the 420R I/V resistors at 5V supply voltage, output is measured at about 1.3V RMS with a 0dB sine wave. That is1.84V peak to peak. Consumer 0dBV is 1.414V Ref level. That is +2.28dB. Not sure about the calculation.

[OnkelPH]

With the 420R I/V resistors at 5V supply voltage, output is measured at about 1.3V RMS with a 0dB sine wave. That is1.84V peak to peak. Consumer 0dBV is 1.414V Ref level. That is +2.28dB. Not sure about the calculation.

Thanks

[bobdcarr]

I am offering my protodac unit. It has SPDIF / Optical inputs and works great. If anyone is interested, please PM me, Bob.
[attachment=3817]

Refer to this post for more info: https://moodeaudio.org/forum/showthread....4#pid53694

[thomaschan]

I have added a tube output stage to the 1387 DAC and the improvement is HUGE! The design is based on Lampizator published years ago before he started selling US$50K tube DAC. Very simple and easy to DIY.

https://www.youtube.com/watch?v=z_XzmpK62pc