Audible Illusions Modulus 3A troubles

Measure power supply voltage.

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

@kevinshunt, you should ask for a full credit refund on your Audible Illusions Modulus 3A preamp.  The preamp was preowned, and you have no clue else might go wrong. Sometimes you repair one thing and something else breaks.  Others on this Forum may have a different opinion but THIS is my opinion. 

I have heard that common issues with the Audible Illusions Modulus 3A preamp include problems with the tubes, which may need replacing with high-quality ones to prevent excessive noise or distortion.  

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

@kevinshunt, as per your post above, have you contacted the seller? What did they say? Please keep us posted.

Two things:  Is your cartridge a moving magnet or at least a high output moving coil?

Secondly, are you aware of the mute switch which is pushed in while the unit is not playing, but must be out when playing music?  I've owned both an Audible Illusions 2D and 3A for many years.  It's also been about 10 years since I've owned one.  What I just wrote about the mute switch maybe just the opposite.  

The AI's are very long lasting units if you use the AI tubes.  It is also a very good sounding unit with phono built in.

Bob

eing on both right and left channel makes me feel there is something else going on. unless the seller sold the unit not working correctly. Something could have happened during shipping as well. nice unit though when working correctly. 

+1, “Contacted them last Friday, hoping to hear back Monday, they are a reputable reseller out of CO”.

It is possible something broke during shipping. In any case, based on your post, the Audible Illusions Modulus 3A unit needs to be returned for a checkup.

If it was just the phono section, it could be you are running a very low output moving coil cartridge. Unless it has the optional John Curl phono board, the regular Audible Illusions phono board does not have much gain.

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.

Did you at least contact the seller.

I hope it works out but

Id thing new tubes might not be the problem..

They are great preamps I have owned 4

Yes it was advertised in full working order

Was it offered as a working unit?

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.

Return it if it was offered as a properly working unit.

DeKay

If you are not willing to buy tubes return it. If I am correct the 6n23p reflector are the ideal tubes for Audible illusion they last longer than other tube..check them out if indeed they are the right one.

Agree. If you otherwise are pleased with the condition of the unit, spend some money on a set of tubes instead of return shipping. You probably would have ended up buying tubes in short order anyway.

The tube filaments are powered continuously even when the power switch is in the off position. Even though the amount of electricity to the filaments is at a lower level, the tubes don’t last as long.
 

I bought a used Audible Illusions L3 linestage. When I replaced the tubes with new ones I was amazed at how much better it sounded. It had much more gain since the setting on the volume knob was at a lower point for the same loudness. Try new tubes before you return it. Good luck.

@pwerahera +1 Good suggestion! Buy and try a new set of 6922's before returning the preamp. The joys of tube gear ownership!

Return it…

Tubes in this AI unit may need to be replaced. AI designs push the biasing of these 4x6922 tubes to their limit. So potential lifetime of tubes is much shorter compared to those from preamp circuit designs from other manufacturers such as Audio Research, VTL, etc. You can buy 4 JJ 6299 tubes for $29/each from Amazon. You can get this to work without breaking the bank.

Sorry, pic is not my unit, tape section has been tested

@hiend2 , more like 6 years!

Turn the tape monitor switch off. It is separate from the input selector.  It is one of the large controls, same size as volume

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.

Make sure nothing obvious is going wrong i.e. you've selected the wrong input mute is engaged stuff like that. If nothing like that's going on send it back.

To sounds like a tape monitor switch is on ect.

Return it, if it needs servicing dont return to Audible illusions as you wont see the unit for 6+ months

+1, I also would return it. The unit is not working.

A common problem is with the tubes; they may need to be replaced with a new, high-quality set. Additionally, excessive noise or distortion might indicate a malfunction within the preamp itself. Further investigation into the preamp’s internal components may be necessary. I Suggest you return the unit. ASAP!

I would just return it. You've confused input and output impedance with sensitivity, btw.