Aion Andromeda (nobels odr-1) Issue

Started by bal704, November 09, 2018, 02:48:50 PM

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bal704

Just finished building the Aion Electronics Andromeda (Nobels ODR-1).  Everything appears to be working properly, except the output level is very low. 

All the knobs appear to be doing what they are supposed to do (gain changes gain, level changes level etc), but the overall volume is so low it's not useable.  When bypassed, the amp plays at normal volume.  When engaged, barely audible.

I've changed out both IC's, and it didn't help.  Any tips or suggestions?

PRR

Memory is fragile and electricity is invisible.

Give link to documentation.
https://aionelectronics.com/project/andromeda-nobels-odr-1-overdrive/

DC voltages and audio tracing are next. Do what trouble-expert R.G. says:
https://www.diystompboxes.com/smfforum/index.php?topic=29816.0
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reddesert

Traditional debugging advice:
- check the DC voltages on each pin of the ICs
- use an audio probe to follow the signal through the circuit and find out where you are losing volume.

It's rarely the actual ICs that are a problem, especially if they are common op-amps, and especially if the circuit is passing signal. A volume loss problem could be a cold solder joint, or a wrong value resistor that attenuates your signal, bleeds it to ground, or sets the gain of an op-amp to an unintended value.

Hanzo

Quote from: bal704 on November 09, 2018, 02:48:50 PM
Just finished building the Aion Electronics Andromeda (Nobels ODR-1).  Everything appears to be working properly, except the output level is very low. 

All the knobs appear to be doing what they are supposed to do (gain changes gain, level changes level etc), but the overall volume is so low it's not useable.  When bypassed, the amp plays at normal volume.  When engaged, barely audible.

I've changed out both IC's, and it didn't help.  Any tips or suggestions?

I just built the same pedal and am having the same issue.  I'm going to start troubleshooting soon but if you got yours working please share so I can rule out circuit design (since this is a newer one I haven't seen a successful build report).

Thanks

aion

Without seeing any troubleshooting data (IC/transistor voltages) I can't speculate much, but the first thing is to make sure your JFETs are from a trusted source - they're not really available firsthand anymore and there are a lot of off-spec fakes circulating (Tayda, eBay).

PRR

Welcome.

> rule out circuit design (since this is a newer one I haven't seen a successful build report).

?? The Aion page shows 12 build reports, several "no problem". The doc PDF is 3 years old so not very "new". Aion is known for good products.

Odds are incorrect assembly, OR as Aion said fake JFET. Bogus JFET is often revealed with Voltage Readings (why we love to see numbers). Several sorts of other build errors tend to reveal themselves as you poke voltages around the circuit.
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aion

Quote from: PRR on November 11, 2018, 05:30:43 PM
Welcome.

> rule out circuit design (since this is a newer one I haven't seen a successful build report).

?? The Aion page shows 12 build reports, several "no problem". The doc PDF is 3 years old so not very "new". Aion is known for good products.

Odds are incorrect assembly, OR as Aion said fake JFET. Bogus JFET is often revealed with Voltage Readings (why we love to see numbers). Several sorts of other build errors tend to reveal themselves as you poke voltages around the circuit.

There is a brand new version that came out in August for the 125B form factor, which I think is what Hanzo is referring to. The original poster didn't specify which version he was using, but could also be the 125B one. (both versions are still available depending on preferred enclosure size)

There are several dozen of the new ones out there in the wild and I haven't heard of any issues so far - and of course my original prototype is fine - but it's always possible there's a documentation error that would lead to it not working. It's only happened maybe two times in five years, so pretty unlikely, but not impossible in the way it would be if there were several hundred over three years like the earlier version.

But yes - voltages & more details please!

bal704

The issue was a solder bridge.  The first opamp the signal hits from the input had plenty of volume on pin 2 and 3, very little on pin 1.  There are several components between pin 1 and pin 2.  An adjacent solder pad was bridged to one of these pads.  Once I fixed that, it works fine.

I did have to order some 2N5457 transistors off ebay.  That transistor is apparently discontinued, and somewhat hard to find.  The ones I got seem to work.

Overall the pedal sounds good.  It works as designed. 

Hanzo

Quote from: aion on November 11, 2018, 08:46:06 PM
Quote from: PRR on November 11, 2018, 05:30:43 PM
Welcome.

> rule out circuit design (since this is a newer one I haven't seen a successful build report).

?? The Aion page shows 12 build reports, several "no problem". The doc PDF is 3 years old so not very "new". Aion is known for good products.

Odds are incorrect assembly, OR as Aion said fake JFET. Bogus JFET is often revealed with Voltage Readings (why we love to see numbers). Several sorts of other build errors tend to reveal themselves as you poke voltages around the circuit.

There is a brand new version that came out in August for the 125B form factor, which I think is what Hanzo is referring to. The original poster didn't specify which version he was using, but could also be the 125B one. (both versions are still available depending on preferred enclosure size)

There are several dozen of the new ones out there in the wild and I haven't heard of any issues so far - and of course my original prototype is fine - but it's always possible there's a documentation error that would lead to it not working. It's only happened maybe two times in five years, so pretty unlikely, but not impossible in the way it would be if there were several hundred over three years like the earlier version.

But yes - voltages & more details please!

Thanks - yes I'm building the new one but almost certainly is my error.  Was just curious if OP got theirs working before I dug in.  Wish me luck...