I am looking at the schematic for the Boss GE-7 equilizer and can not figure out what the first opamp is. It's part number is U5A and identified as a HA12017. It appears as an op-amp but I am unaware of what pins 5 and 3 are for. Is this an obscure chip, and if so, where can I find a substitute? Thank you.
William
P.S. I have done a google search for the datasheet using both HA12017 and just 12017 but didn't find anything. If someone could point me to a datasheet, I would really appreaciate it.
Sorry, I can't find a datasheet either (try going to usbid and asking for one), but it IS an op-amp, I believe often used as a pre-amp. Manufactured by Hitachi.
-Colin
I have somewhere fragments of a datasheet, but not at home. I will look for the stuff. I used it 20 years ago in a design for a multitrack tape recorder head preamp. Basicaly it is a (really) low noise Opamp, designed for use in moving-magnet pickups (that is used on this vintage turntables, if you remember :D ). it can be run on higher voltages than a normal Op-Amp (gives more headroom). also used in Ibanez RM-60 Rack-Mixer.
be careful, sensitive against static discharge. use a protection diode from input to V+ and another one to V-.
analogguru