Help - Preamp with LM1036

[rampage101]

I've noticed this nice little chip (LM1036) from NS, it seems it would be perfectly suited to my gainclone. But what I don't understand from there schematic in the PDF, is what/where the POT's go to control the Bass/Treble/Balance etc. Could anyone possibly point this out to me?

 

[Andypairo]

The LM1036 is "DC controlled", so the DC level at the control pins sets the effectiveness of volume, balance, etc.

quoting from National website:

Four control inputs provide control of the bass, treble, balance and volume functions through application of DC voltages from a remote control system or, alternatively, from four potentiometers which may be biased from a zener regulated supply provided on the circuit.

Cheers

Andrea

 

[rampage101]

OK. So what would be the ideal way to use this as a preamp for my gainclone? I'm new to all this sort of electronics stuff, but I'd like to learn.

 

[Arius]

You can simply use the LM1036 per the suggested schematic shown in the datasheet. This IC allows a fully functional Tone, Volume and Balance preamp to be easily made.

The reference schematic works and you can use a switch for the loudness function (more tone boost at lower volumes). I recommend operating it at 12-15V. As the supply is single ended, you must use input/output caps per the schematic. The chip tends to get warm as it dissipates >300mW during normal operation.

Note that the LM1036 cannot handle high level inputs (e.g CD player outputs at 1Vrms). It works best with 100-300mV input. So add resistors/op-amp buffers where necessary depending on your application.

I used the LM1036 for a simple computer amplifier before so I cannot comment on its sound quality, only that it works as advertised.

Good luck.