Audible Illusions Modulus 3A noise

I spent some time with the lid off & found out of the 4 tubes that one seems ok & the other 3 produce a pronounced hiss.  I swapped it to the other side and the hiss changed sides, this was with no sources hooked in.  I would suspect amps, amp cabling, or other issue with the M3A had the sound not travelled with those tubes when swapped.  I need backup tubes anyway, guess I'm going to search around to see what I can find.  I emailed AI but haven't heard back yet - anyone know if the replacement tubes they sell are electro-harmonix?

Kevin

Hi Kevin,

Yes that's a good sign. The AI is dead quiet with tubes in decent shape. A bad hum 'usually' indicates a bad transistor whose noise does not travel.

EH will last a bit longer, but not nearly as long as Voshkod,OTK, Rocket Logo etc.

Enjoy your AI. If you want the ability to use real NOS 6922/7308 email me or IM me.

Mitchell

I use (below) with Deoxit D5 to clean sockets. For tube pins you can use D5 BUT, it will remove the printing - been there/done that. I use very fine steel wool with denatured alcohol, dependin g upon how badly tarnished the pins are.

https://www.cvs.com/shop/gum-proxabrush-go-betweens-cleaners-wide-prodid-767370?skuId=767370&cgaa=QWxsb3dHb29nbGVUb0FjY2Vzc0NWU1BhZ2Vz&cid=ps_oralc_pla&gad_source=1&gclsrc=ds

@wheezer1 Fully agree. I've tried several others through the years which only lasted a short period. Only the Russian ones last a long time. Keep in mind that the originals, as matched pairs are becoming more difficult to get. There is a lot of fake offered.