BC127 / BC127-HD ADC performance


I cant find any information about the ADC for the mic / line inputs in the BC127 module.
Can anyone give me some information?
Since the BC127-HD supports 24bit/96k-Audio, is there a better ADC implemented?
I’m developing a bluetooth-boombox with additional line-input and I’m not shure, if the ADC in the BC127 is suitable for the line-input.

Thanks for your help!



The HD is a slightly different hardware build from the standard one and it is all designed to match together, what information are you after?




Hi there !

I will use this topic as I have related questions.
I cannot find any information regarding ADC input characteristics. Does anyone knows:

  • Input impedance (Single End / Diff)
  • Input voltage for Full Scale output (Single End / Diff)
  • Common mode bias ? (i.e. should inputs be AC coupled, or biased to a level, and which one ?)

I want to use BC127 as a transmitter for line-level analog signal, not microphone. So I have to design my analog front-end to meet specifications (that are absent of the datasheet…)
I do not plan to use the +20dB gain configurable in Melody (dedicated for microphone use)

If anyone can help.
Thanks !


Sorry, but nobody did never used the analog input of BC127 ?
Does anybody knows the full scale voltage input ?

Thanks !


I went over what I know about the ADC in another post:

The peak to peak full scale input is around 1.6 volts as far as I can tell. The input impedance varies from 6k to 30k depending on the gain setting. For a line level input you’ll want to use a low gain. You should AC couple the inputs.

Set a very low output gain then vary the input gain to find the right level (so you know any overload comes from the input amp).


Hi BPT !

Thanks a lot for this answer, this surely helps !