Ampeg B15N - Resistor / Rectifier Help!

Discussion in 'Amps and Cabs [BG]' started by bassybass1010, Jun 16, 2016.

  1. bassybass1010


    Jun 16, 2016
    Newbie here - hello!

    So I have a 1970 Ampeg B15n. The rectifier tube has been changed over to a couple of resistors and I have a couple of questions.

    How does this affect the sound?

    It has been converted to work with UK voltage (no step down needed) - was this a result of that? And it is possible to convert it back for use with a rectifier tube?

  2. beans-on-toast


    Aug 7, 2008
    I don't think that you have the full details. Either you need a solid state rectifier or a tube rectifier in place. You can not substitute the rectifier with two resistors. The amp will not work work that way. If your amp is working, they did something else.

    Secondly, you need the proper transformer. If you increase the voltage on the power line side to 240 with a 120VAC transformer in place, you decrease the current capacity on the secondary side of the power transformer will decrease below the level demanded by the amp. There are no shortcuts. Either buy a 240VAC transformer and have it fitted or use a 240 to 120 external voltage conversion transformer. You can purchase a universal transformer from in the US, Power Transformer PT108 for Ampeg B15N/B12N - Product Details. This will allow you to use the tube rectifier or, if you wish, a solid state rectifier.
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