Spectron or Spector of death?

[Carlinb17]

Hello, I've been trying to troubleshoot an aion spectron. I've jumped all the expressions and loops in order to try and nail this down. I get no effect, I do get bypass and I get signal when activated. I can get the sensitivity led to work if the input is extremely high but there is no effect. I've tried a couple of different lm358 and lm1458 with no change.

Here is the build docs
https://aionfx.com/app/files/docs/spectron_documentation.pdf

My voltages for the LM358 are

11.1mv
65mv
.9mv
3mv
2.5mv
4.15v
4.16v
9.1v

Any suggestions or help would be great.thank you in advance!

[idy]

Voltages seem odd for the 358. Pin 4 should be 0, 3mv is close, but maybe turn power off and make sure that pin shows continuity with ground.

The second half of the opamp also seems funny: it is a buffer, taking the voltage from the trigger (the first half of the same IC) and making sure it can provide enough current to drive the LEDs. Pins 5,6 and 7 should all be the same.

[FUZZZZzzzz]

I can also see some suspects of solder that might need some reflowing..

[Carlinb17]

Pin 4 has ground.

When I throw in lm1458 chip I get these which seem better I think

8.45
7.1
3.8mv
.1mv
8.45v
7.59v
7.58v
9.14v

I still get bit effect with this op amp

[antonis]

Did you get measurements on op-amp pins or on respective socket ones..??

P.S.
I agree with @FUZZZZzzzz about reflowing..

[Carlinb17]

Did you get measurements on op-amp pins or on respective socket ones..??

P.S.
I agree with @FUZZZZzzzz about reflowing..

I got them on the op amp pins, and I will reflow today. Thank you

[idy]

Good working voltages for the 358 (which is much better than 1458, you can read about this in the docs from Avon or check out the "building the meatsphere" thread)
should be;

0 on pin4, 9 on pin 8, and all the others less than one volt.

The first opamp is "biased" to ground; when the signal hits it it is rectified  into DC which charges a cap (smoothing it out), and that voltage drives the second half of the opamp. So you should see less that 1v when no signal. By the way, if the LEDs are lighting up when you play, the 358/1458 is working. If no filtering is happening then the problem is in the other ICs, the filter.

Are you sure about all those knobs and switches? Must test with; bandwidth full, Sensitivity max, attack min, decay up higher than attack, like 1/4, color half to full, intensity full, mix more than half. Any of these set wrong and...no filter maybe. Try different settings on the filter mode (LP BP HP) and if some work but not others, that points to the filter. Again, if the LEDs are lighting up, the problem is not in the 358/1458.

I always had to use a booster in front of mine until I started using 358 and adding a 1-2v bias to that chip. Which is covered in the meatsphere thread. Which is pretty long and repetitive, but worth a scan.

[Carlinb17]

Thanks, I reflowed last night and will look at it some more today, if I understand correctly based on the numbers it could be one of the 72 op amps correct?

[idy]

We haven't seen those voltages yet! Just saying, if the LEDs are lighting up when you play, the 1458/358 is doing its job.

The other two opamps are really 4 in two packages. One provides a signal buffer at the input (if you are getting a good clean signal when the blend is at minimum, that one is probably working.)
The other three make up the filter. If the lights are flashing but no filter, could be lots of things. Lots of solder joints, resistor/capacitor values....

[Carlinb17]

Ok I reflowed, and here are the numbers doe the 358


220mv fluctuates slightly
42mv
.7mv
.2mv
1.1v
250mv-300mv fluctuates
450mv-500mv fluctuates
9.13v


When I switch the sweep to the second position I get this on the 358

1.1 my
.8mv
.9mv
.6mv
220-270mv fluctuates
1.67v
1.69v
9.11v

[idy]

We put numbers next to pin voltages to make it easier for others to read, and to clarify our own thinking re what pins you are talking about and what they are supposed to do. And weren't you LEDs lighting up? If so, obsessing on the 358/1458 won't help.

1) 220mv fluctuates slightly
2) 42mv
3) .7mv
4) .2mv
5) 1.1v
6) 250mv-300mv fluctuates
7) 450mv-500mv fluctuates
9.13v


"When I switch the sweep to the second position I get this on the 358"

1) 1.1 my
2) .8mv
3) .9mv
4) .6mv
5) 220-270mv fluctuates
6) 1.67v
7) 1.69v
9.11v

I am not seeing anything here. Mine looks like:
1) 1.68
2) 1.68
3) 1.68
4) 0
5) .89
6) .89
7) .89
9.35

When I flip the sweep switch to "down" (Default LED is on) I get
1) 1.6
2) 1.6
3) 1.6
4) 0
5) .89
6) 1.06
7) 1.06
9.35

Notice nice groups of three pins with the same number? It is not unusual for the + inputs (5 and 3) to be loaded a bit by the meter and read low.

When you use the "first position" of the sweep, is that when the LED is normally off until you play? And in the "second" it is normally on until playing darkens it?
Please clarify that you have set the knobs and switches as mentioned, how are the LEDs doing, and what is sound is coming out.


One funny thing about this circuit is that the voltage out does not change between the two settings, sweep up and sweep down. Instead, the LEDs and their power and ground are flipped around and the opamp "sources" current in one position and in the other "sinks" it. In one it acts as a + power source, and in the other it acts like a negative ground.

[Carlinb17]

Thanks for the info, I actually had it fired up last night out of the box, when I boxed it no effect. So I think I have a grounding issues somewhere. Going to start going through it now looking for that