INA134-DRV134 balanced preamp

[raul_77]

I want to build a balanced preamplifier, as I don't need gain I think to use the INA134 and the DRV134, with a volume potentiometer between them.

I can use the suggestions of circuits from the pdf's:

http://www.ti.com/lit/gpn/ina134

http://www.ti.com/lit/gpn/drv134

Or I can use this designs:

Electronique - Realisations - Symetriseur audio 006

Electronique - Realisations - Desymetriseur audio 005

The question is that, in the datasheet of the DRV134, say that need be feeding for a low impedance source, so are need a buffer between the potentiometer and the DRV134.

I can made one... as I can made a hole in a box and hold a sepaker, yes, sounds, but the problem is optimize, same thing happens to me with the buffer.

Any suggestions for the design of buffer between the potentiometer and the DRV134? Any scheme? Or someone has the whole scheme of a preamp like this?

As power supply I think use something like this:

Aunt Corey's Homemade Buffered Passive Preamplifier Schematics | Stereophile.com

http://www.mediafire.com/conv/9659fb4fabaf735515298a53416b54d6210ebd68606bd07e33b1a531a111f65a6g.jpg

Anticipated thanks.

 

[mickeymoose]

What is the purpose of this preamp? I/O impdances, levels, balanced or not? Do a single-line diagram to enlighten us. E

 

[raul_77]

Hi mickeymoose,

I have a pair of active monitors and I added balanced outputs to my cd player. All balanced preamplifiers are extremely expensive, so I want to make one.

I have the components to make it, I can just add a potentiometer between the INA134 and DRV134. But I want to do well.

Surely a balanced preamplifier may be of interest to more people, active speakers are good and cheaper than the HiFi speakers, If anyone has any suggestions, please, put it here.

Happy days

 

[mickeymoose]

This schematic of one of the sites you mentioned should work for you: Electronique - Realisations - Preampli micro 007
The SSM2017/2142 are the equivalents to the INA/DRV134. Leave out all the parts needed for the phantom power and replace R5 with a pot to give the desired gain. E

 

[gootee]

You should also read Chapter 6 of ADI - Analog Dialogue | Op Amp Applications Handbook

And reading Chapter 7 would be a very good idea, too.

 

[tomchr]

Have a look at the LME49724. It does exactly what you want and is optimized for audio.

~Tom

 

[mickeymoose]

The LME49724 is a nice part, but where dos t he pot go? E

 

[raul_77]

Thanks for your responses, but I have in mind simple use a opamp, well adapted to the circuit.

The zip file attached show the basic idea, are for simulated in Tina TI. Tina TI can be download here:

SPICE-Based Analog Simulation Program - TINA-TI - TI Tool Folder

Happy days