Thanks Andrew.. Great site!

I’ve been researching the Rivera-era range of amps since 2004 and it looks like they made around three thousand Bassman 20s. The confusion arises when people misread the tables at the back of the excellent Teagle and Sprung book – it’s easy to mistake the ‘original price in dollars’ column for ‘how many made’. My website (info only, non-commercial) http://www.stratopastor.org.uk/strato/amps/twoseriesfenders/twoseriesfenders.html

The trouble with the Bassman 20 is that it uses a Princeton output transformer, the power transformer is Champ sized. The output transformer is way too small for a Bass amp. You would do better to put a Deluxe Reverb output transformer or something with a bigger core. Once that is done the circuit has to be modified to allow the bass response to pass through the amp. I have removed this stuff only to find out the amp distorted very easily. With a better transformer set and a little modification it would be a better sounding bass amp.

It’s not going to put out as much low end as a ported 15 with a 100 watt head. But it puts out plenty for recording. You don’t need to move much air to get all the bass you need for recording situations. Most engineers roll the bass off pretty substantially also compared to what you hear from an amp. It won’t ever sound like an Ampeg or Mesa, but it’s not supposed to.

The trouble with the Bassman 20 is the transformers. The output transformer is from a Princeton amp and not up for the task of reproducing bass, in fact the amp purposeful rolls off bottom end to stop early distortion.