where I can buy tubes to my ALLNIC PRE (3A/110A and 3A/109B)

I'm at work now and don't have my spreadsheet  but I think there are quite a few  DHTs with 4 volt heaters that would work in this application.  My lampizator GG3 uses DHTs in the output stage and I am a huge fan of DHT preamps.  PX25 is one.  You may not be able to put the covers on but I like to be able to see the tubes anyway.  To be clear, I haven't confirmed it is ok to use but you should consider it.  there are others.

I'll add the tubes you use to my list of possible tubes to try in my DAC.

--Jerry

Ask a Tube Dealer.

I agree, contact Allnic or one of their dealers in the the USA (I assume).

I have a great tube dealer but it takes him 3 months to ship so it depends on whether or not you need the tube, and if you have patience.

audiotubes.com

vintagetubeservices.com

Try the above, hopefully they have your tubes.