Audible Illusions Modulus 3A noise

I recently purchased a used Rogue 99 Super Magnum with phono stage. When I hooked it up I could hear static noise/hissing which was not acceptable. Before I did anything I replaced all of the tubes which were tested for shorts, Gm, and noise. These were purchased at a premium (only a few dollars more than standard retail). After warming up for 30 minutes I placed my ears next to a speaker and turned up the gain and volume to max. I couldn't hear a thing. Then I brought in my wife who has incredibly sensitive ears and asked her if she could hear any hissing, humming, buzzing etc. NOPE!!! I had the preamp connected to an Accuphase A-36 power amp and then to Fritz Carrera speakers. My signals input to the preamp were a Yamaha CD-S2000 and Thorens TD-1601 with Ortofon Cadenza Blue cartridge. That system as assembled is very quiet now.  

@wheezer1 I haven't done any cleaning & not sure exactly sure how to accomplish this, I suppose there are many YouTube videos with those details, do you have any tips?  Is this what folks use de-oxit (sp?) for?  what implement, like a bottle brush or special brush?

Thanks - as you can tell I've not done this before.

Kevin

If you want to try NOS, stick to Tungsram 6922s. Those and the premium only Russian tubes mentioned above, are the only tubes you can count on for superior reliability and sound. I’ve had more than 30 yrs enjoyment from my 3a and 3b, following this mantra. When I ventured astray, I paid the price.

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