SE Electronics Z3300a

[Emmathom]

Is your DMM auto-scaled or do you manually switch the measurement range?

auto-scale Volts or mV

 

[micolas]

R2 and R3 must be matched better
Upin2xlr = Upin3xlr

i match them with 0.1% accuracy

 

[micolas]

try connecting the LED in both configurations, knowing that an LED limits the reverse voltage. And with normal diodes the same.(several in series, they only have about 0.6...0.7v).

 

[Emmathom]

Well... ??

 

[micolas]

Well... ??

just test, measure.
with leds, diodes.
*we also have plan C

 

[micolas]

measures how much +/- V supplies the dc/dc for polariz capsule, in the microphone Orig
with Presonus Phantom

 

[Emmathom]

Orig-mod in Presonus :

Pin 2 = 37,88v / Pin 3 = 37,89v / D2 = 18,12v / D2+D1 = 29,82v / R18 = +60,72v / R19 = -60,73v / before R5 = 34,70v / after R5 = 21,45v / Fet D = 16v / Fet S = 0,46v / SA1015 e = 2,52v / K105 D = 29,42v / K105 S = 9,91v

here's the Mod (recall)
Pin 2 = 38,79v / Pin 3 = 38,87v / D2 = 17,20v / D2+D1 = 28,24v / R18 = +56,02v / R19 = -56,04v / before R5 = 32,81v / after R5 = 20,55v / Fet D = 15,85v / Fet S = 0,36v / SA1015 e = 2,82v / K105 D = 28,10v / K105 S = 8,17v

 

[Emmathom]

it seems that D2 is a 18v zener and D1 a 12v zener ?
what not simply increase the second one for one with more voltage ?

 

[micolas]

it seems that D2 is a 18v zener and D1 a 12v zener ?
what not simply increase the second one for one with more voltage ?

that was plan c
but I thought you don't have many zenner diodes to make a combination for the second microphone, to provide voltage like Orig

 

[micolas]

I would only put a 33v Zenner in each, very equal, and I would get 65..70v

 

[Emmathom]

that was plan c
but I thought you don't have many zenner diodes to make a combination for the second microphone, to provide voltage like Orig

I have a good choice of 1w zeners...

 

[micolas]

Orig-mod in Presonus :

Pin 2 = 37,88v / Pin 3 = 37,89v / D2 = 18,12v / D2+D1 = 29,82v / R18 = +60,72v / R19 = -60,73v / before R5 = 34,70v / after R5 = 21,45v / Fet D = 16v / Fet S = 0,46v / SA1015 e = 2,52v / K105 D = 29,42v / K105 S = 9,91v

These values are correct

 

[micolas]

I have a good choice of 1w zeners...

in reality, Zenners also have a large dispersion of parameters.
In both microphones identical zenners are mounted, but in reality they have different parameters.
I would put something like that
33 v
20+12 yrs
24+8.2 v
etc.
(Since the oscillators also work differently, they have different gain transistors
So I would put the total Zenner a little bit bigger in MOD microphone

 

[Emmathom]

I would only put a 33v Zenner in each, very equal, and I would get 65..70v

2 z make less noise than one (?) so I could put a 15v or 16v at D1 ?

 

[micolas]

2 z make less noise than one (?) so I could put a 15v or 16v at D1 ?

Yes

 

[Emmathom]

Yes

Ok so I replace D1 by a 15v to start with... and we'll see...

 

[micolas]

Ok so I replace D1 by a 15v to start with... and we'll see...

Replace D1 by a 11..12v

 

[micolas]

Replace D1 by a 11..12v

and increase the value step by step, and measure
you don't want to burn anything

 

[Emmathom]

I desoldered D1 and tried to measure it : my tester says "it's damage" > can't read any value but 0,625V in reverse...
But I can read the exact values on my 1w zeners...

I tried to look at the data on the z : I think it's written Z27V (?) it must be a 1/2 or 1/4w and it's so small !

But if D1 was dead current would not flow thru it and I would not have tension ???

 

[micolas]

I desoldered D1 and tried to measure it : my tester says "it's damage" > can't read any value but 0,625V in reverse...
But I can read the exact values on my 1w zeners...

I tried to look at the data on the z : I think it's written Z27V (?) it must be a 1/2 or 1/4w and it's so small !

But if D1 was dead current would not flow thru it and I would not have tension ???

it's good, it measures like a normal diode