Pro Audio Design Forum

Cool, I will leave the cap in. I am sketching out a breadboard diagram for a buddy who wants to build one. My brother (who works for a company which specializes in DIGI tal DESIGN ) put it on the AP at work and discovered that my breadboard construction gave it a very low level hum (like -120 dB) wi...

Wayne - Sorry, I'm still a little confused. I've built my THAT 1510 preamp with no internal phantom power supply on the premise that the user will have to provide his own phantom power. Thus, the blocking electrolytics on the input have been omitted, as well as the 22k resistor to ground and the 6.8...

OK, I will leave the center resistor out as I'm omitting those coupling capacitors. I have considered both the 1510 and the 1512. After extensive testing I've found that below 40 dB of preamp gain I start to hear the A to D noise of the recording device. This preamp will have fixed gain of 40 dB. If...

Thanks for the very informative reply. So I'll be OK using the two 3.3k resistors and 22k for the center resistor? I should mention that my design omits the phantom-power blocking capacitors. Strange, I know, but if you want phantom power you use an external supply. My preamp is used for testing mic...

Using the T-bias scheme, what impedance will a mic see? I'm concerned about loading dynamic and ribbon mics. I have built a preamp around the 1510 using two 3.3k resistors to ground using the rule of thumb that the input impedance should be 10x the mic impedance (I do have a 600-ohm mic, AT804, and ...

Thanks, Wayne. I am about to rebuild my 1510 preamp and will be incorporating your modifications to the basic design from THAT Corporation.

What is the purpose of the 200 pF capacitor between pins 2 and 3?

What is the purpose of the 200 pF capacitor between pins 2 and 3?