Tubes for Modulus 3A

what is the difference between the 3a and 3b? There is no mention of the 3b on AI website.

The differnce between a 3a and 3b is about 12 months of wait time. All joking aside Art made severial refinements (I would need to review the manual) but I was never able to pin him down. That being said it's a great unit.

Sorry I can't be of more help.
Tony

Art Ferris called me this evening regarding a post I made about my secondary preamp the Modulus 3 (origional) I have a problem with one channel in the phono section and we had a great chat. He said their web site will be updated before the end of the year and that he is making the 3b now and it has much more refinements than the 3a. He did tell me to be careful regarding the EH6322 tubes as the newer ones are junk, perform poorly and microphonic as hell.

He really made my day!

Bob

You should get your tubes from him... more often than not it is better IMO to go to the manufacturer.

Tony

I have owned a Modulus 3A for many years. I breathed new life into my unit by replacing the 400V 100UF electrolytic capacitors with new ones; same brand and value.
One of the electrolytics is too difficult to replace, I left it in. I found room to replace one of them with a Jantzen cross cap metallized polypropelene 100UF 400V capacitor.
I believe this will solve your problem. As for the tubes, the 3A does not give any great response to expensive tubes.