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DIY Stompboxes => Building your own stompbox => Topic started by: rschultz on June 24, 2023, 03:31:17 PM

Title: Aion Azure CE-2 Output level too high
Post by: rschultz on June 24, 2023, 03:31:17 PM
The Aion Azure is a CE-2 with added mix knob. Just built one and it works... but the output level between on and off is very different. On being much louder. I have triple checked all my resistors and orientations. I feel that it probably is related to IC1, the input and output op amp. Both inverting op amps, I think the input gain is R7/(R5||R4) and the output gain is (R9||R10)/R8. Those are inverses of each other, so that would make sense to gain it up, modulate it, then gain it down the same amount and inject the chorus mix in the output. So I'm not sure what else to check.

(https://i.postimg.cc/dhJM2Srn/IC1.png) (https://postimg.cc/dhJM2Srn)

(https://i.postimg.cc/75zVLxfW/Schematic.png) (https://postimg.cc/75zVLxfW)
Title: Re: Aion Azure CE-2 Output level too high
Post by: antonis on June 24, 2023, 05:15:01 PM
Output amplitude is restricted by supply rails voltage..
(about 8Vp-p or 2.8VRMS..)

If your only issue lies on loudness, you can form an output voltage divider with a resistor to GND after R11 or, better, place a Volume pot after C7..

P.S.
The above gain calculations are correct only for high frequencies.. :icon_wink:
(where 6.8nF caps exhibit a negligible impedance..)
Title: Re: Aion Azure CE-2 Output level too high
Post by: rschultz on June 26, 2023, 10:50:40 AM
I think this is a buffering issue. WIth the effect ON, it's buffered. With it off, true bypass. Initially I was plugging the pedal directly into guitar. But after I stuck it in my pedal chain (with buffering before it), the On/Off levels seemed much closer.
Title: Re: Aion Azure CE-2 Output level too high
Post by: ElectricDruid on June 26, 2023, 06:23:14 PM
Quote from: rschultz on June 26, 2023, 10:50:40 AM
I think this is a buffering issue. WIth the effect ON, it's buffered. With it off, true bypass. Initially I was plugging the pedal directly into guitar. But after I stuck it in my pedal chain (with buffering before it), the On/Off levels seemed much closer.

I don't see how this makes any difference. Yes, the pedal is buffered. And yes, when it's true-bypassed that buffer isn't in the circuit. But how exactly is the buffer supposed to make the signal louder when the pedal is on? And how would putting *another* buffer in front of the pedal help the situation? I just don't get what you're proposing. What exactly is the theory about what's going on, so we can work out how to test it?

It's late here, so maybe I'm just being dense, sorry.