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latest revision: http://halfshavedyaks.xyz/forumimages/4mic2chanV3.png Initial layout suggests that the board will be about 40mmx65mm though I will try to make it smaller. Thickness will be about 15mm

R1, R4 etc are the source resistors for the fets in the capsules. the capsules are not depicted as they wouldn't be on the board. As I mentioned earlier it might be desirable to make these trimpots,

In this case all the simulator is doing is ohms law, so it is trustworthy - purely for the avoidance of stupid mistakes rather than any great insight. I wouldn't trust it in some more complex

I'm guessing these 'simulation' programs are for the 'obedience of fools and the guidance of wise men' ?... Listing voltages to 3 decimal places is clearly nonsense. No two 'real world' examples of

OH NO the actual link is this: http://halfshavedyaks.xyz/forumimages/4mic2chanSeriesPower2.png

Yes there were some obvious stupid mistakes notably I showed 48v at the XLR pins and worked down from there which is rubbish. sorry it was really just to show the topology. I have done an improved one

I don't think the 'real world' voltages will be anything like those you've listed in your 'sim'.. Assuming a total current drain of 4mA , then each of the 4 'legs' of the feed will need to supply 1

I just noticed two conceptual errors in this rough schem. 1. opamp power consumption is not constant - it is 1.8ma per opamp quiescent, but it will increase with signal. So the opamp power needs to be

I've found that many attempts at internal frequency response corrections within the microphones? themselves can often tend to be too simplistic to be really useful. Passive filters are often the

Yes, I mean low shelf along with a high frequency notch that is needed with some cheap capsules. There are some interesting cardioids out there that don't have a very steep rolloff. Only 3dB per

Along with the OPA board, you will need a hex inverter (or other means of getting bias voltage) to make this all work. See this for more: https://www.instructables.com/True-Condenser-OPA-Mics/ -- Best

Newbie. Ordered this capsule from 34mm capsule ( https://www.amazon.com.mx/gp/product/B09CTB3WD1/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 ) Unsure about what OPA to build. Please advice. Thank

here's a? schem to show the idea of what I mean about stacking the power supply. To use the same current twice like a schoeps. http://halfshavedyaks.xyz/forumimages/4mic2chanSeriesPower.png current

why those values? I'm not challenging it - I'm just not sure what your criteria are. If the bal and vol pots are the same size then with the balance pot all the way over there is a 50% reduction in

firstly, this is a quick draft - component values are not optimised and the power supply isn't the bit that's new or interesting. However the zener is there to protect any 25v or less caps in the

thet wrote: Yes, the typical accordion pickup system does this -- the left-hand cable threads through the bellows (they snake the wire in an "S" shape and tape it to the tips of the bellow creases to

I agree that in this case the filtering should eliminate anyzener noise. I just can't see the point of introducing a potentially noisy regulator where it's not needed. In the worst case here -

One probably explains the other... What do you mean by equalize? If you mean compensating LF loss with some kind of boost EQ, you need to realize that the drop reaches 12dB/octave, which is quite

I agree, partially. I'm not worried about zener noise, since it is conveniently filtered by R7/C4. But I agree with increasing the zener voltage, unless the opamp maximum rail voltage is exceeded.

I would use 20k for balance and 50 or 100k for volume, assuming there is an opamp after. It's something you need to experiment with. With large chromatics, you can run the wires along the left and