Voltage Divider for Op Amp

[Bouquin]

Hello!

I have been trying to build a replica of a simple pre-amp from a 1970s era echo machine. It is important to me that, for the moment, I keep the device as close to original design spec as possible.

The op amp, as I have discussed in another thread, is a Toshiba TA7136P. The circuit now is up and running and I am powering its -/+14V spec with two separate 10V DC adapters that measure 14V each under small loads.

I have been researching common ways to power op amps for guitar effects pedal applications and I am wondering if there is a common way to build a voltage divider that responds well to the current demands of an op amp (whatever those typically are). For instance, if I were to power the preamp with a 18V, consumer "pedal power" type device, what circuit would reliably split that into -/+9V for me?

Thanks!

 

[rayma]

if I were to power the preamp with a 18V, consumer "pedal power" type device,
what circuit would reliably split that into -/+9V for me?

http://www.ti.com/lit/ds/symlink/tle2426.pdf

 

[Bouquin]

http://www.ti.com/lit/ds/symlink/tle2426.pdf

Wow, this looks promising! Looks like it will halve an input so would I need two of them? How would the negative half work? And two would independently manage their respective + and - without any contact between the two?

Thanks!

 

[Bouquin]

Sorry, I got ahead of myself. Looks like the single one will do the job. This seems to be the common way to set it up, right?

http://tangentsoft.net/elec/bitmaps/vgrounds/tle2426clp.png

So, can it be safely assumed that the current draw of this op amp does not exceed 20mA? Sorry for the basic inquiries! 😀

Looks like the max supply current draw is 4.2mA for my op amp....

 

[rayma]

This seems to be the common way to set it up, right?
http://tangentsoft.net/elec/bitmaps/vgrounds/tle2426clp.png
Looks like the max supply current draw is 4.2mA for my op amp....

Yes, this should work ok for you.

 

[Bouquin]

Another question about the tle2426: Should the virtual ground be connected to the true ground shared by the rest of the circuit?

 

[rayma]

Another question about the tle2426: Should the virtual ground be connected to the true ground shared by the rest of the circuit?

Yes, to the output of the TLE2426 circuit.

 

[raul_77]

Project 43 - Simple DC Adapter Power Supply

 

[Bouquin]

Yes, to the output of the TLE2426 circuit.

Thanks! How come this circuit is shown with a capacitor? Is that necessary with the tle2426? Will it not work as a stand alone device?

 

[rayma]

Thanks! How come this circuit is shown with a capacitor? Is that necessary with the tle2426? Will it not work as a stand alone device?

Most amplifiers and regulators need a capacitor on the power supply terminals for proper operation.