Audio input impedance

Nick123

Hi,

I’m planning to build a custom guitar pickup system and I’d like to match it properly to Bela’s inputs.

Could you please tell me the input impedance of the audio input on Bela ?

My goal is to design the pickup (impedance, output level) so that it is well matched to the audio input without an external buffer, if possible.

According to ChatGPT, it is a much better solution to connect the guitar pickup to the analog input using a DC offset and not directly to the audio input, is that correct? Bing AI wrote the opposite, not to use the analog inputs. I am an absolute beginner in the subject, the AI mixed it up well. 🙂
(It will be a hexa pickup, it needs to be connected to 6 channels)

I haven't ordered the Bela yet, I might wait for the Gem version, but I might buy an earlier model to start with, maybe the older experiences and feedback I find online will be useful.

Thanks a lot!

giuliomoro

Gem Stereo and the first two channels of Gem Multi have 10k input impedance (see TLV320AIC3104 datasheet). The remaining ten channels of the multi have adjustable input impedance to 2.5k, 10k, 20k (see TLC320ADC3140 datasheet)

Nick123

Thank you for the answer, now I understand how the devices work, I can find information on the data sheets.
The Bela Mini Multichannel Expander Starter Kit would suit me, I would like to order one, but it is currently not available in the EU shop. Will this product be available later?

giuliomoro

the Mini Multichannel has been discontinued and replaced by the Gem Multi, which is currently available for preorder here