Indeed nothing new on this circuit but making something by myself is very interesting. The circuit contains 2-ch 3-band equaliser circuit with Lipo battery charing circuit as follows

LiPo single cell produces 3.7 V and not all operational amplifier working well such a low and single voltage. I found JRC 2115D, which is suitable for this purpose.

Here is a parts arrangement. Most of them are lead-axial type and quite easy to make!

Now the full parts kit is sold at tindie.com for $25.

Actual operation can be found in the following movie... have fun!