Audible Illusions Modulus 3A troubles


Just purchased a used Audible Illusions Modulus 3A preamp for my system but only getting very very faint sound when turned all the way up.  Plus the very very faint sound is very fuzzy as well. 

I popped off the top & re-seated the 4 tubes but that was no help.

My 2 amps are both rated at 50k ohms input sensitivity, so this is the right preamp for them at around 1.2k ohms output sensitivity, running a biamp configuration.  AI documentations confirms this.

I've tried each amp on its own, using both output RCAs on the preamp, to no avail.

How to tell what is wrong...looking into the return policy, but at least the shipment was insured.

Any ideas?

Thanks-Kevin

kevinshunt

Showing 10 responses by kevinshunt

yes, i've been through each setting, each input (they all come through in the same very very quiet manner), even to the point of adjusting the jumper switches behind the tubes - they also had no effect.

Is there a way to prove that it is the tube?  Is it ok to swap them around?  I've heard one should keep the tubes in the same place.

in the manual there is a good description of how to test tubes by rotating the two for the line stages, so will try that.  I haven't tested phone input yet, they have their own set of tubes.  Four 6922s in total - I've found the least expensive JJ brand for around $22 each.  Will do this today during the Bears game, as I don't expect to be happy about their performance against Packers.  Anyway, will try this to see if anything stands out.

Yeh it’s the very very faint sound when at full volume that may be a non-tube issue

Contacted them last Friday, hoping to hear back Monday, they are a reputable reseller out of CO.  Yeh I'm disappointed as I really wanted to hear it in my system, it's replacing a Peachtree Nova pre that's out of rca inputs.

Sending the unit back - can have refund, fixes, or store credit.  Was wondering if trying to let them fix it is worth it?

They give a 90 day period, if they can even get it working, so gonna go ahead and risk it

Seller replicated the issue and the fix they did was to install a new power cable from the outboard power supply to the unit,  should get it back soon, looking forward to hearing it in my system.

Thanks everyone tor your advice,

Kevin

So it sounds great in my system, actually there is a noticeable difference that I appreciate, highs and mids are clearer and presented in space more vividly. Bass is pretty much the same (great).
 

Kevin