Aion Quantum Build Problems

[ElectricDruid]

I think I mentioned in the original post, there's no volume until the last 1/4 turn or less on the volume and distortion. And the volume drops like a rock if you turn either past a 1/4 turn down.

In the original post (Dec 19th) you said everything was fine up until the volume control. But now you're saying there's a problem with the distortion control too? That's a lot earlier in the circuit.
We need an accurate description of the symptoms or the diagnosis doesn't stand a chance!

[DanZ]

I don't think it's anything with the distortion, just lower volume. Just like with other pedals, if you turn up the gain, the volume tends to go up.

I checked through the resistors again, and they're all correct. I'm about to check all the caps again.

I'm so half tempted to buy another and start over again. I had problems with a pedal a couple of years ago. Could never trace it. Bought a new PCB and worked right out of the gate.

[ElectricDruid]

Ok, if you take your audio probe and test either the output of IC1B (pin 7) or the top of the Volume pot (leg 3) and you've got a solid signal there with distortion and tone controls working smoothly, then I think we can move on.

If the signal up to there is good, the problem can only be afterwards. That doesn't leave much, just the volume control itself and the output buffer, so we should be able to fix it relatively quickly.

Can you post photos of the volume control and the area around Q2? We should take a look and see if we can spot anything. If you've been staring at something for a while it gets very hard to actually *see* it. A pair of fresh eyes often works wonders.

Don't give up yet! You're so close!

[duck_arse]

Q1 voltages are too high. please be so kind as to measure and post the voltage at the VC point. measure [that is - MEASURE ] the resistance from that point to both ground and VA. and report findings.

as the holy one sez - photos. [are druids holy or just wise? or just old?]

[ElectricDruid]

[are druids holy or just wise? or just old?]

Better ask Getafix? (Panoramix, for non-English-language readers).

Us Electric Druids mostly loiter about electric stone circles looking for trouble, the lack of which gives us plenty of free time to hang out here instead...

[duck_arse]

Q1 voltages are too high. please be so kind as to measure and post the voltage at the VC point. measure [that is - MEASURE ] the resistance from that point to both ground and VA. and report findings.

So I checked all the voltages on Q1 & 2 and the IC and are as follows (the ideal voltages are in () )

Q1
E 6.04 (3.68)
B 6.67 (4.10)
C 9.47 (9.44)

well now I am confused. are the wanted volts in brackets, or the measured bad, cause I calculate that the VC should read 6V4 about, which makes your "measured" good but your "ideal" bad. bad as in too low by 2V5 abouts. [4V1 is either 28k/22k or 9k1/6k9. abouts.]

[antonis]

Stephen is right..!!

ALL voltages (including IC..) are GOOD..!!

Pin's 3 "deviation" is due to meter loading bias resistor (R7)..
As for Q1 & Q2, single resistor bias configuration (R2 & R15) are strongly dependent on particular BJT beta (h_FE) and V_BE..

[duck_arse]

coffee for me?

[antonis]

coffee for me?

Outchhhh..
(my bad..)