Are large numbers of channels superior to smaller numbers ? [resolved]
I'm trying to build a neurofeedback setup in order to attempt to treat my mental health (there is no neurofeedback facility in my country). So far I have only found a 128-channel 10-5 system cap in china for 120 usd, which is quite good price. I'll be able to use it even with lower amount of electrodes.
So far I don't know how many electrodes do I need, so I'm thinking why not the highest number 128 channel? However, after browsing for a bit, looks like diy people don't build 128 channel eeg setups?
This EEG-SMT looks like it's only for 5 electrodes https://www.olimex.com/Products/EEG/OpenEEG/EEG-SMT/open-source-hardware
Here is 24 channel but price is above high https://www.alibaba.com/product-detail/New-EEG-Trolley-Machine-with-eeg_60599438069.html?spm=a2700.galleryofferlist.normal_offer.d_title.38c4ee99USWoJy
Where is the 128 channel eeg amplifier, so that I would have support for max number even if I later turn out to decide to use less electrodes?
And why would it be so expensive, shouldn't it be like a relatively simple device for electrical engineers who understand the mechanism? iPhone seems way more complex and it's cheaper than some of those 24 channel eeg amplifiers