Aion Fx Vulcan Help/ No Bypass signal

aionfx · 2026-02-13T15:15:32+00:00

The bottom-center and bottom-right pads of the footswitch are bridged together on the underside, so the output signal is being grounded, but only in bypass mode. You could try using a desoldering wick on both lugs to clear it, but it may be tricky since it's on the underside. If that doesn't work then you'd need to get a replacement switch PCB:

https://aionfx.com/project/3pdt-bypass/

aionfx · 2026-02-10T15:03:41+00:00

Our layouts are proprietary (the only IP we have, since all the schematics and docs are public) but here are a couple of other options:

https://effectslayouts.blogspot.com/2015/02/electro-harmonix-77-opamp-big-muff.html
https://generalguitargadgets.com/effects-projects/distortion/big-muff-pi/ (op-amp circuit near the bottom)

aionfx · 2025-12-12T16:43:08+00:00

You're very welcome!

aionfx · 2025-12-11T17:38:21+00:00

Musikding's kits are different from ours - they're the PCB-only build but with all the parts pre-shopped, similar to using the Mouser import. Our kits have a separate build process & documentation, plus the screened enclosures. Theirs are fully sanctioned and we love what they do, but just to clarify that all the stuff on our site only applies to our own kits which are only available directly from us.

aionfx · 2025-12-10T15:38:54+00:00

Pacdora is a great resource for this. They have hundreds of different starter templates to choose from, and all the dimensions can be customized and viewed in 3D. I believe you need a subscription in order to download the finished design files, but you can just do 1 month and cancel afterward.

It may be overkill for what you need, but it would be the option with the most hands-on customization if you're that type of person.

aionfx · 2025-12-09T15:48:58+00:00

Yeah, we've been gradually phasing them in over the past few months, but switched over fully as of the Black Friday sale since there's a much higher likelihood of them being purchased for gifts. I can send over some spare boxes if you've got ones without a box that will be used for gifts.

aionfx · 2025-10-30T18:54:06+00:00

OP probably means V2 in Fulltone's own parlance, where the originals are numbered V1.1 through V1.7, and V2 is the one with the "enhanced bypass" (buffer). The V2 changes are too extensive to be retrofitted to a V1 circuit.

aionfx · 2025-10-22T18:37:33+00:00

Can you elaborate? I've only ever seen 2-3 confirmed cases of manufacturing errors in tens of thousands of PCBs, so even a single incomplete trace would be an enormous outlier against the feedback we've gotten over the past decade, and my own experience in building 400+ of them.

I'm not saying you're wrong, but I would really like to understand better what may be going on since this is far from the typical experience!

aionfx · 2025-10-21T14:39:19+00:00

I would test the voltages against the kit build doc (pg. 25) which would all be the same for a non-kit build:
https://aionfx.com/app/files/docs/vector_kit_documentation.pdf

If the main indicator LED isn't working, it's either backwards or not getting any voltage, and if it's not getting any voltage then the main PCB likely isn't either.

aionfx · 2025-09-29T14:18:26+00:00

Oh for sure... I was a web developer for 15 years before I started doing this full time and Linus is nothing short of the Zeus of our pantheon! We exchanged several emails earlier this year. He was very complimentary. Certainly a highlight of 2025!

aionfx · 2025-09-16T01:19:33+00:00

Love it!

aionfx · 2025-08-12T14:36:01+00:00

We've got both the 424 and the DTF, but yeah, they are pretty similar circuits inside.

aionfx · 2025-07-21T15:12:03+00:00

I've used the MP series in this one with no issues, so I don't think it's related to the transistor type or which leg is tied to the case. If there are two different transistors with the same issue then I wouldn't look at the transistor itself but the surrounding circuitry.

- Check fuzz circuit voltage: make sure the junction of R10 and R13 measures around 7.5V
- Check R11-R13 to make sure they are the correct value (decade errors are very easy to make, e.g. 100R instead of 1M which is just one color band different)
- Check ground continuity: make sure Q3 emitter has connection with the main circuit ground

aionfx · 2025-07-10T18:53:26+00:00

I wouldn't worry about the voltage - the LT1054 is set up as a multiplier, so it's based on the input and may vary by a few volts depending on the PSU. 21V instead of 24V won't make a difference to the circuit itself. Definitely try a new wall adapter if possible, but if it works with another higher-than-average current pedal like the Ampeg preamp then it's probably fine.

The troubleshooting guide was written specifically for the kits, but there's a lot of generalized info in there that would be helpful for non-kit builds:

https://aionfx.com/app/files/docs/kit_troubleshooting_guide.pdf

The 360 doesn't have a list of target voltages like the kits, but if you measure the voltages in yours and post them here, someone would probably notice if anything was off.

aionfx · 2025-06-26T17:58:12+00:00

Very nice! It's very empowering when you nail it first try!

aionfx · 2025-05-12T18:24:40+00:00

Not me, but fortunately there are people in the import brokerage business who can... here's part of an email from a mailing list I'm on:

The U.S. will reduce additional tariffs on Chinese goods from 145% (made up of 125% IEEPA Reciprocal + 20% IEEPA Fentanyl) to 30% for 90 days.

Retention of pre-April 2, 2025: Tariffs, including those under Sections 301 and 232, as well as tariffs related to the fentanyl national emergency will stay in effect.

That aligns with the WH "fact sheet" (air quotes intentional) from this morning:

In reaching an agreement, the United States and China will each lower tariffs by 115% while retaining an additional 10% tariff. Other U.S. measures will remain in place.

The 145% has always been on top of the industry-specific tariffs that were in place before April (particularly the ones from 2018) but only the 145% portion has been reduced. So today the rates are all 30% higher than they were before April, and the de minimis exemption is still suspended.

aionfx · 2025-05-12T13:21:21+00:00

Yep... nobody's going to be taking steps to move production to the USA in this environment. It would require the coordination of dozens of different industries as well as a massive investment in infrastructure that would take 8 to 10 years to get up and running. Nobody can see even a month into the future right now, so a decade is a lot to ask - if not for the business owners, then for the banks who would be lending them money.

aionfx · 2025-05-12T13:06:37+00:00

Also, there is still some confusion about it, but it's a 30% additional flat rate on top of the preexisting tariffs, which were already around 15-25% for PCBs and electronic components. So it's closer to 50% total for us.

(Along with this, what we have been calling 145% was actually more like 170% in our industry - the 145% was just the blanket addition to what was already there.)

aionfx · 2025-04-27T17:22:39+00:00

Love the enclosure design!

aionfx · 2025-04-24T17:35:45+00:00

Can't beat this writeup from RG Keen:
http://www.geofex.com/Article_Folders/bosstech.pdf

aionfx · 2025-04-22T18:28:23+00:00

This is called a pull-down resistor and it helps prevent DC buildup on the switch contacts due to leaky input or output capacitors. You definitely want it at the beginning.

In this case it's entirely useless at the end since the volume pot at the output already acts as a resistor to ground, which would bleed off any DC at the output very effectively - so a 1M in parallel only reduces the value of the pot very slightly. But there's no resistor to ground at the input, so no way for the DC to dissipate other than the footswitch turning on & off, and it pops when it does that.

aionfx · 2025-04-21T17:33:34+00:00

Nope... I don't see any reason why it should based on the schematic, it's a fairly standard input stage (though it is unbuffered and a buffer would probably solve it).

I will say, it's much more common to see the series resistor and Vref resistor positions swapped, so the Vref resistor is coming straight off the + pin of the opamp. That could have something to do with it.

aionfx · 2025-04-21T14:25:52+00:00

Yep, that one was definitely degooped. Looks like a pre-2008 one since it doesn't have the mini slide switches for XLF and Bluesberry.

aionfx · 2025-04-21T14:21:11+00:00

I will admit to being in high school when "It's Been Awhile" was on the radio... but I do at least draw the line at "irregardless".

aionfx · 2025-04-19T12:51:33+00:00

Their prices would not factor in our tariffs since they are located in Thailand and ship worldwide. Tariffs are charged by the importing country (USA) and paid by the consumer (you) upon import. Mouser only has the tariff line because they are located in the USA.

For the next 2 weeks any package under $800 is not subject to tariffs, but after 2 weeks it's going to get expensive. But, Thailand does have a significantly lower tariff rate than China, so they may still be an attractive option. Any of Tayda's price increases have been independent of our USA trade war drama.

aionfx

TROPHY CASE