Modify a Silvertone 1448 amp-in-case

Discussion in 'Amp Central Station' started by dkevin, Jun 24, 2019.

  1. dkevin

    dkevin Tele-Meister

    Posts:
    205
    Joined:
    Mar 13, 2011
    Location:
    Seattle, WA
    Let us imagine a world where someone has time on his hands and wants to redesign a Silvertone 1448 amp-in-case. Originally this amp is a transformerless amp using a 12AU6, 50C5 and 35W4 half wave rectifier. If this certain individual wanted to replace these tubes with a 6AT6, 6AQ5 (similar to a 6V6) and a 6X4 full wave rectifier what is the most economical ($) way to power this amp? The original operating voltages seem to be irrelevant for our purposes because the tube lineup has been altered. I...I mean HE would be looking for a modest 250vdc on the output plates. If my math is close, that would require a 230-0-230 PT to provide the plate voltage I need. Anyways, if you have a helpful suggestion, drop a line and I will make sure this guy hears about it.
     

    Attached Files:

  2. Dacious

    Dacious Poster Extraordinaire

    Posts:
    6,528
    Joined:
    Mar 16, 2003
    Location:
    Godzone
    You could back-back two 6.3 volt filament heaters - I did this to create a one tube amp with a 6GW8, which has a triode plus preamp . Use a 6AU6 with your 6AQ5.

    You will easily get a watt or two with that. Don't bother with a rectifier tube, just use a full bridge.

    So you connect the two filament heaters 6.3 to 6.3 volt, and use the HT off the second with a voltage doubler to get you 240 volts which rectified to DC is enough.

    The filament transformers cost almost nothing. If you really want, you can use a little line transformer for the output, pennies.

    Or, get really trick and use two 6AQ5s in push-pull.....
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.