Hello , i know it is an old post , but what do You think of this pcb ??? it might help to polarize LDC , it s based on the shematic featured upper in the thread ... would it be "easy" to implement in the Frankebtube design ??? Hex Inverter Voltage Multiplier for Condenser Microphones - Share Project - PCBWay. today i m building it to make OPA Alice mic
If you take the VCC for the DC-DC PCB from the 10V point (Zener Cathode) on the FrankenTube circuit, it may work. With 10V the DC-DC board should provide about 60+ volts for capsule polarization.
Such a shame, looks great. What went wrong?Ive tried something similar few years back. No succes on my side....
No Franken tube mic circuit but slightly adapted 6418 tube di box circuit plus dc-dc converter for polarisation voltage. It was nice experience though
Are you using the original opamp recommended for the build, from a reliable source? Also you can check if the noise comes from heater supply by replacing it temporarily with a 1.5v battery.
I am currently using opa134ua, is there any difference compared to the opa134pa? and about the heater I am going to try that, maybe there is something wrong with the heater supply.
Pic?
This is a board that I have bought from a seller, and the op amp that he used is an opa134ua, maybe I should switch the opamp to opa134pa?
I used a 1.5v battery for the heater, the noise is still there but it does improve a lot, maybe there is something happening with the heater supply? what can I do to improve that?
I asked before, how do you know it's a genuine opa134 at all?
the one that Ive bought are bur brown opa134ua(not sure is it a fake one or what), because the one that the seller provides have no brand on it so I decided to use a more reliable brand.
true
no way it will work, so maybe it's not the problem of soic8 version or dip8 version.
