Well the $5 preamp is a Bit misleading, Firstly the INA217 will run you close to $4 in singles, and a Proper Power supply will run you upwards of $20 even on the cheap, Pluss you need a Chassis as a Piece of Verto Board and a Jumble of wires won"t last to long in a Studio, You also need to buy a Male and Female XLR connector, Pluss that guy omited a lot of the Circuit which will lower it"s performance Pluss if you want Ballanced output you have to add to the datasheet Circuit, also if you want Gain controll you will need a special 10K Reverse Log Taper Potentiometer or a specially made Rotary switch....
To build the circuit properly in a Proper Chassis with a Proper power supply and XLR connectors and a Gain Knob is going to run you at least $20 per channel......
I am actually building a couple 4 channel Rack units useing the INA217 right now ,They will be Ballanced in and out, with Phantom power and 66db of Gain (60db unballanced) useing my own design(simular to the Datasheet but with a ballanced Line driver at the output to ballance the Signal and my own home etched PCB"s useing the chassis from a scraped Yahama compressor......
Because I got many of the Parts for free (Transformer ,INAamps ,Chassis, ECT) it will only cost me about $50-$75 for each 4 channel Unit Pluss my time but I might sell one of them to get some money to build a few more, I have enough INA217"s to build 12 channels pluss 4 INA103"s for a few different Preamps....
This circuit here can be built for probably $2 (Minus connectors ,PSU ,Chassis ect) and actually sound pretty good and has pretty low noise, I have another that is only slightly more complex and has Ballanced in/Outs but only about 35db gain but it can be boosted with use of a dual opamp.....
Cheers
And I can probably get it on the 'bay for cheap cheap.
