A very weird (to me) issue with an Audible Illusions Modulus L2B ...

This is my second AI preamp - they sound fantastic but, as we all know, their CS is sh*t, which is why I'm posting here rather than wasting my time trying to call them (I've been waiting for 9 months for a response to a query about getting a copy of an owner's manual for my 30+ year old S-120 amp - after several phone calls, e-mails providing name, rank and serial number at Art's insistence, and unfulfilled promises).

Anyway, about 3 months ago, the blue backlight behind the selector knob went out.  Not really a big deal, and I figured I could live with it that way as it didn't affect the sound in any noticeable way. I just assumed that the diode/led/whater-it-is had burned out and that eventually I'd get around to replacing it. BUT, when I turned it on about an hour ago, the 'broken' backlight is working perfectly fine, but the lights behind the two smaller center knobs (left and right gain - remember, this is the L2B line stage, not a full function preamp, so the knobs are slighlty different, but presumably, the backlighting scheme is the same) started flickering (not in sync with one another) and now they are out, but the one that's been out for 3 months remains on. And, as I'm writing this, the light behind the right gain knob just came back on, but the one behind the left gain knob is still out.  The light behind the main volume knob seems unaffected.  Obviously, these backlights are not in the circuit, so this is essentially a cosmetic issue, but I'm wondering if anyone else has experienced this and what, if anything, they did to fix it.

Thanks, and Happy Turkey Day!!




We had an old farmer neighbor in the early 70s who bought a new Chevrolet.  As part of gov’t meddling in new car manufacturing his new car had a large, square seatbelt warning light in the middle of the dash that would not go out until the driver’s seatbelt was fastened.  He solved that annoying problem with a piece of black tape strategically placed directly over the warning light.  

Your problem might benefit with a similar solution.

Sounds like cold solder connections on the circuit board behind the front panel controls. I had a similar problem with the original Modulus 3.  Lucky for me, it took only a week to get repaired at AI but that was in the 90’s when they were located in California. 

Agreed with @stereo5. If you possess soldering skills, maybe give the board a look see under a magnifying glass. Perhaps something will stand out as needing a little reflow. Another option is to send the unit into a reputable repair facility. PCX in Canada repairs hi-fi. As far as the lower 48, I’m not sure who to contact. Maybe Frank Van Alstine would give it a look? 

Thanks @stereo5 ​​​​and @wturkey. I figure it is something like that too. I’m hoping someone might chime in who knows where to look - I have no problem going in with a soldering iron, but I’m less confident at being able to spot the bad connection, and totally confused about why it’s affecting more than one light, but not at the same time. Guess I’ll have to take off the front panel and poke around. I do have a competent tech - unfortunately he’s got a 6 month backlog, but I do already have a vintage (‘73) Marshall tube amp on his waiting list, so maybe this is a good excuse to check in with him.


As for the tape suggestion, I’ll assume you’re joking or just misunderstood. I’m trying to get the backlights to stay ON, not cover them up. Either way, thank you for your folksy wisdom.

@boxcarman - the S-120 amp is 30 years old (and still fabulous), but I can’t rely on the owner’s manual for the current S-150.



Lordy. Or he could have put on his seat-belt and potentially saved EMS having to untangle his remains from a tree. Without "gov’t meddling," no one could walk away from a 30mph crash in an unmeddled sedan unharmed. Complain about government interference in the bedroom instead.

would not go out until the driver’s seatbelt was fastened.

Too funny.  The 1960s-70s was a different world.  We rode in the back of pickup trucks and bicycle helmets didn’t exist.  We had lawn darts and clackers.  Clackers were two hard plastic balls on a string.  The trick was to swing them so the balls bounced back and forth against each other.  Eventually, when the balls shattered and had maimed enough little kids, they were banned.  Lawn darts were 2 lb spears that were tossed into the air with the goal to land them in a small hoop on the ground.  Not pretty when they landed on someone’s head.

Smoking was as commonplace as bottled water is today.

What I miss the most are French fries cooked in trans fat.  Nothing compares to the taste of fries in the good ole days.

My uncle talked of a time- up until the 1940s when you could see how your new shoes fit by putting your feet under a flouroscope at the shoe store.  That’s right, an x-ray machine sitting out in the open in a shoe store.  They were phased out when people’s feet started falling off, apparently.

Gov’t meddling or personal freedoms/choice.

Thank you for hijacking my thread with wistful remembrances of the good old days. I was born before 1960, I remember them well. It was acceptable to pinch girls’ on the @$$ too. Try that now on my granddaughter and they won’t find where my son and I scatter your pitiful remains. So, it’s been fun reminiscing, but your answer is still entirely inapposite to my question.