Aion Electronics Nimbus - no effect

[ajhuff]

Hello, please bear with me because I really don't understand electronics very well. I've built two pedals kits, a spring reverb kit from BYOC and a Helios distortion pedal from Aion Electronics. Both woked perfectly when I buttoned them up and plugged them in. I am pretty good at following directions, going slow, being methodical. I can do kits with good directions.

So I wanted to see if I could start with just a board and build a pedal. So far it seems I can't.

I bought the Nimbus overdrive board from Aion and sourced everything else. Making this one of the most expensive pedals ever. I have it plugged into a Voodoo Labs power source. With the guitar plugged in, pedal on, I get guitar sound as if plugged straight into the amp. No change in tone or sound. Turning the volume, drive or tone knobs does nothing. If I switch the power off, it's as if I unplugged the guitar. No sound to the amp. So I guess it's not passing through.

I've read the trouble shooting sticky and I need to start even more basic than that I guess. I bought a 9v battery jack that I can plug into the pedal for power. With my DMM I confirmed the plug is negative power by putting the negative lead into the plug and touching the positive lead to the outside of the barrel. That reads about 9V, 8.5 I think, new battery. I then plugged the battery into the pedal. I put the negative lead of the DMM on the pedal box and then touched the positive lead to the center of the jack output or where the wire connects the jack to the PCB board and I get -14.9 mV. So it seems I'm doing something wrong from the very beginning.

Hopefully someone would be willing to hold my hand here, walk me through this and teach me a little.

[ajhuff]

This is the DC power jack I bought off of eBay. Did I buy the wrong thingm

[ajhuff]

Here's the reading I get

[Marcos - Munky]

First of all, welcome!

If I got it right, your power supply is negative center. But you're using a metallic power jack.

The metallic jack is touching the outside lug of your dc plug, which is positive. But it's also touching the enclosure, that is wired to ground, that is wired to negative of the dc jack. So it is as if you're shorting the positive and negative pins of your power supply. This is indicated by your measurements, you get 9V before connecting the dc brick to the pedal but get almost zero after connecting it to the pedal. A dc brick will just disarm, while a battery will discharge quickly and get pretty hot.

To be sure, just do this: remove the dc jack from the box. You may have to desolder the wires. If yes, then resolder the wires again and make sure the dc jack isn't touching the enclosure. Connect the power plug again. Test the pedal again.

If it's working, then the problem is the metallic jack. Just get a plastic one. If the problem isn't solved, let us know to tell you the next steps.

[ajhuff]

The battery does get hot!!!

Sounds like I need to replace it with a plastic one regardless..I picked it just because it looked cool. I never knew there were reasons not too. Thanks! I will order a plastic one and post results after I get it. Probably next week.

-AJ

PS Thanks for the over simplifying your explanation. I actually understood you.

[Marcos - Munky]

So your battery is probably dead. Rip.

You can use the metallic one if you use a positive center power supply. But the standard power supplies for guitar effects are negative center, you you'll have to use a power supply that'll work for your pedalboard but nobody else.

Before ordering the plastic dc jack, do the test I told you to do, with the dc jack removed from the enclosure. So we'll know if that is the only problem, and hopefully it is.

[ajhuff]

I cut the wires and reattached outside the box with the jack just hanging in space and not touching anything. When I plug the battery in I get the same readings as before and the battery gets hot. I checked and it's an 8V battery now. So I will just wait until I get a plastic jack and eliminate this as a source of error. And before I screw something up.

Thanks!

-AJ

[DIY Bass]

If the power jack was not touching the case and the battery still gets hot then you have a short on the power supply somewhere on the board.  Take your multimeter with no power connected to the board, and measure the resistance between the +ve and ground.

[ajhuff]

OK, so if I put one test lead at point A and the other test lead at point B, I think that's what you mean, my meter reads 6.7 when the dial is set at 20K Ohms.

[DIY Bass]

OK, R20 and R21 join together.  Measure from that join to both of the pads you have already used (A and B (Gnd and 9V) from above).

[ajhuff]

Good morning. I might not understand what you mean. I got 6.6 for each.

I measured with one test lead on the +9V (I labeled A above) to the right leg of the R20 resistor and got 6.6 with the dial set at 20K ohms.

I measured with one test lead on the +9V (I labeled A above) to the left leg of the R21 resistor and got 6.6 with the dial set at 20K ohms.

I measured with one test lead on the  GND (I labeled B above) to the right leg of the R20 resistor and got 6.6 with the dial set at 20K ohms.

I measured with one test lead on the  GND (I labeled B above) to the left leg of the R21 resistor and got 6.6 with the dial set at 20K ohms.

It was pretty consistent. The second decimal would be different but it was 6.6 something for all of them.

-AJ

[duck_arse]

please assist us to assist you - post photos of your built board, both sides, and shots of your offboard wirings, please. it is also polite to at the very least provide a link to a circuit diagram or build docs of the version you've built.

thank you.

[ajhuff]

Sure.

[ajhuff]

I'm not sure how to post the wiring diagram since it's a PDF but here is the link to the board.
https://aionelectronics.com/project/nimbus-maxon-od-820-overdrive-pro-pcb/

[duck_arse]

assuming this is your version .....
https://www.dropbox.com/s/3mayaqit8atqnju/aion-nimbus-od820-documentation.pdf?dl=1

I can't see much from your far away pics [we like to be close enough to read the resistor colour bands], but two things: are all you tantalum capacitors the right way around? they are marked with a (+) leg as opposed to normal electros, marked for the (-) leg.

and - I couldn't see it mentioned in the docs I linked, but I think your diodes D1 and D2 should solder to the first and fourth pads when only fitting singles; you have soldered to second and third, which from what I see on yer blank pcb, are shorted pads.

[ajhuff]

OK thanks. That's the one.

Yes, I didn't understand where the diodes went so I put them in the two middle holes. So they should be in the outer holes. I will fix that. Thanks!

I feel good the capacitors are correct because I paid close attention. Is there a way to double check? Unless you're saying I used the wrong kind to start with?

I'm not sure how to get a better picture with my phone but I'll see what I can do.

-AJ

[ajhuff]

I played around with the manual settings on my camera phone, I've never been in there before. Maybe these are a little better.

[Marcos - Munky]

Just to be sure, what's the resistence between +9V and gnd pads? The ones you labelled A and B. Measure with the probes directly on them, with no power.

Also, can you remove some parts from the board to do some testings? I mean, do you have the tools/skill to remove a part without damaging the board from overheating if asked?

[ajhuff]

Hi. Yes, that 6.7 number I measured was with no power on. I don't know what that means.

Yes, I can desolder. Back in college I worked at a plant making High I drives and power supplies. I had no idea what I was doing or even what a high I drive was, but like I said I was really good at following directions.

So I may not understand what I'm doing, but will follow whatever directions you give me.

Thanks!

-AJ

[ajhuff]

I had to source everything from scratch. The resistors were easy. But I did struggle on buying the capacitors. Perhaps I bought or used the wrong thing. So I put together a list of what the instructions called for and what I bought.

Build List      What I purchased

C1 100n      Wima 0.1µF 5% 63V
C2 1uF film   Wima MKS2-1.0/63/10 1uF 63VDC 10% Polyester (PET) Film Capacitor Radial
C3 100pF 1   100pF, 50V, radial leaded multilayer ceramic capacitor, coating by epoxy resin.
C4 100n      Same as C1
C5 220n      Wima 0.22µF 5% 63V
C6 10n      Wima 0.01µF 5% 63V
C7 220n      Same as C5
C8 10pF 1      10pF, 50V, radial leaded multilayer ceramic capacitor, coating by epoxy resin.
C9 220n      Same as C5
C10 10uF 2   16V 10uF tantalum
C11 20pF 1   20pF, 50V, radial leaded multilayer ceramic capacitor, coating by epoxy resin.
C12 1uF film   Same as C2
C13 100uF 25v   Panasonic FM 100uF 25V Low-ESR 105C USA SELLER
C14 10uF      Same as C10
C15 100uF 25v   Same as C13
C16 10uF      Same as C10
C17 10uF      Same as C10
C18 220uF 16v   Panasonic Radial Capacitor 220uF 16v EEU-FC1C221 105'C Low Impedance
C19 220uF 16v   Same as C19

Semiconductors
Q1 2SK246         2SK246-Y Original New Toshiba TO-92 MOSFET K246
IC1 - IC2 JRC4558D      JRC4558D OpAmp
IC3 TC1044S         TC1044SCPA
D1 - D2 1N914 3      NTE Electronics 1N914 Silicon Ultra Fast Switch Rectifier Small Zener Diode, Single Configuration, 200 mA Forward Current,                                                     10mA Test Conditions, 100V
D3 - D5 1N4001      uxcell a11092900ux0407 25 x 1N4001 Molded Plastic Case Rectifier Diodes, 1A, 50V

1 Can be ceramic or film. I prefer to use multilayer ceramic capacitors (MLCC) for these small values.
2 Can be electrolytic or tantalum. C10 is in the signal path.

Thank everyone for your patience with me.

-AJ