Mic Preamp Buffer

[Reno1]

Hi I am building a mic preamp using the THAT 1510 preamp however I am in need of a suitable buffer to place after my volume pot to got to my tone control circuit any suggestions

 

[SY]

Single ended or balanced?

 

[Reno1]

Single ended or balanced?

Single Ended

 

[SY]

Then a buffer is pretty simple. If you like tubes, an ECC88 cathode follower will work beautifully (if well designed) without adding significant noise. In the opamp world, a unity-gain-connected OPA2134 will give you much bang for buck.

 

[Reno1]

Thanks for the help any recommended circuits preferably using op amps

 

[mickeymoose]

Show us what you have now and what you want to do. Schematic diagramms are the bablefish of electronics. E

 

[SY]

Also important are specifications for:

*Required overall gain
*Gain of the first stage
*Output level

 

[Reno1]

Hi I am basically using the circuit provided on the website for the THAT 1510 preamp THAT Corporation 1510-1512 Audio Preamplifier ICs
I will be using a 50k pot from the output which will feed the tone control circuit.
The tone control will either be a 3 band baxandall circuit, or a 3 band control with sweepable mid. I will probably use the second one i will post a picture when i can find it thanks

 

[SY]

The important missing element is the sensitivity of what you're driving. Some line inputs have one or two volts of sensitivity (max input), others more like seven or eight volts. Other question would be, what does the buffer have to drive? If it's a meter or so of coax, just about any good opamp (like a 2134) that's unity gain stable, strapped as a follower (output tied back to the inverting input, input taken to the noniverting input) will work fine. A 100 ohm resistor at the output will help ensure stability. This all assumes something like a 10k input impedance- if you have a 600 ohm load, we'll need to get slightly fancier.

 

[RogerGustavsson]

Why an additional volume control? You can use a potentiometer in place of the gain setting resistor Rg, use a capacitor in series with it. I see no need to add gain and the reduce it.


Roger

 

[jackinnj]

Thatcorp has a dev board for the THAT1510. I really like their products.

You might also want to take a look at the datasheet for the ADI SSM2019. The 2019's I've been using of late seem to be lower noise than those from 10 years back but I wouldn't want to dissuade from using the THATCorp devices.