Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

The gate voltage depends on the DAC. For example it is at 0V for PCM1704.
You have to judge for your own case, as I have not spent time on your DAC circuit in detail.
If you use an offet voltage you need to change the value of the resistors across caps to make sure they match with the offset.
See the ES9018 implementation (SEN Version 18).

Patrick
 
Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

Could you post a link to the schematic for the cascoded balanced version that sounded so good?-- I tried to find it but the thread is long. Also are folks still preferring Joachim's PSU?. I noticed that the SEN is supposedly sensitive to PSU mains power supply noise hence the common mode choke, alternatively using a choke filter before a Salas.


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Cascode BF862 with LS832

Fair enough about batteries ... haven't read through but I assume you have a row of switches that go from recharge to supply?

The BF862 is indeed attractive because low noise and low cost/easily available. I recall reading that it is recommended to cascode this. Considering the LS832 as a dual low leakage/capacitance jfet for cascode? The U431 used in this article: http://http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2872042/

Reasonable or better with J111, etc.?
 
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2SK2013/2SJ313 has a positive Vgs and is therefore NOT self biasing.
If you start putting in a bias circuit like Leach you add complication AND distortion.

A high bias, high power SEN can be done using my LU1014 Triode Cell (200mA bias).
But you have much more capacitances to take care of.


Patrick
 
We used matched J111's.

I've read the article as well as the discussion regarding the BF862 which is easily available. I also read where you were testing the coupling caps ... Obbligatos for example are not very expensive ... did you find a significant difference? Obviously some extra room on the PCB but if it is at all better then worth it. Do you do this type of cascode (?Borbely type)? I'm sure these are neophyte questions and this circuit may be totally off, but I'm trying to learn.

Am I on the right track?
 

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