Aion Zenth - Phase 90 Clone

Started by josh@dividedzero.com, August 29, 2024, 09:01:07 PM

Previous topic - Next topic

josh@dividedzero.com

I'm building this guy

https://aionfx.com/project/zenith-jfet-phaser/

Almost everything works. I have led, sound on bypass, sound on active, volume pot works great. I used the matched jfets from Aion. I've tried all the zener values listed and same result. No matter what I set the speed and depth or the bias changes anything and there's no phase. I've followed the directions in the instructions to do biasing and there's no difference.

I've completed the Apex from Aion with the same transistors as well as a NomNom and a Smoothie from MadBeans. They all work great. I can hear the difference when biasing and everything is great there.

I've socketed and moved the zener to the back to make it easier to test different voltages but no zener seems to make a difference. I get continuity across the zener and sockets. Pulling out the zener (i.e. empty zener slot) makes no change either. Otherwise everything is as stated in the BOM.

Any ideas? It's got to be simple; i's always something simple.




Chillums

The PCB has a extra pad(s) for different j-fets with different pin outs.  Double check to see if you have them in the right ones as its hard to tell from your pics.

josh@dividedzero.com

I've put them in over the silkscreen. matching the GSD with the GSD on the adaptor PCB they came soldered to. The same way I installed them on the other 3 pedals.

Mark Hammer

Chillkums is correct.  You'd be surprised how often a part with the same "number", but fro another manufacturer, has a different pinout.  Double check the pinout of what you have.

aion

Quote from: Mark Hammer on August 30, 2024, 05:04:07 PMChillkums is correct.  You'd be surprised how often a part with the same "number", but fro another manufacturer, has a different pinout.  Double check the pinout of what you have.
I am pretty sure all SOT-23 JFETs have the same pinout now, even Japanese ones like these. There may be some I've missed so I wouldn't make it into an adage quite yet, but I've looked through dozens of datasheets and they've all been the same.

mac

Quote from: Mark Hammer on August 30, 2024, 05:04:07 PMChillkums is correct.  You'd be surprised how often a part with the same "number", but fro another manufacturer, has a different pinout.  Double check the pinout of what you have.

A year ago I bought a set of matched jfets BF245B ... hFE: 250, NPN  ;D  ;D

mac
mac@mac-pc:~$ sudo apt install ECC83 EL84