Aion FX Neurotron carrier signal bleed

[benjaminstrange]

Hi everybody - long time lurker, first time poster. I've run into a few gremlins with an Aion FX Neurotron build. Everything seems to function as it should, but the VCO carrier signal is bleeding into the main signal pretty bad. I've gone through all the VCO calibration and transformer trimming as discussed in the build notes, and these seem to make no improvement to the noise issue. Have any of you experienced this, and could give me some pointers about where to begin looking to fix this problem?

Also - the blend function makes the entire signal very quiet and muted in the 12:00 position, and it really only seems to put out the proper volume all the way up or all the way down. Could this just be how the circuit was designed? I'm only really getting a decent sound from my bass blended in when the blend knob is all the way down, which doesn't exactly make it very useful.

Any insight you could provide would be greatly appreciated.

 

[chris.knudson]

Q3 looks like it's in backwards.

 

[benjaminstrange]

Q3 looks like it's in backwards.

You're right! Thanks so much - it might have taken me hours to notice that.

 

[comradehoser]

Solved?

 

[benjaminstrange]

Solved?

Not yet - I'm just now having coffee this morning! I'll get it fixed later today, and post back if the issue is solved.

 

[benjaminstrange]

Solved, well, sort of. There's still a tiny bit of bleed, so I'm not sure how much is normally acceptable or not. I used to own a real Lovetone Ring Stinger (bought the entire line brand new in 1999, and stupidly sold them ages ago), so I can't recall if the original is this noisy or not.

The blend pot works perfectly now. Much obliged for the help!

 

[Kris100]

Solved, well, sort of. There's still a tiny bit of bleed, so I'm not sure how much is normally acceptable or not. I used to own a real Lovetone Ring Stinger (bought the entire line brand new in 1999, and stupidly sold them ages ago), so I can't recall if the original is this noisy or not.

The blend pot works perfectly now. Much obliged for the help!

From my own build I can tell you will not find a trimpot position where the bleed goes away 100%. It's kind of like calibrating a BBD for lowest noise floor possible. Well done!