SEplex low gain tweak

Since posting the SEPlex design a few people have built it and I’ve heard that it has, what might be considered, excessive amounts of gain. It does have gain since I wanted EL34 OD sound but I thought it would be appropriate to have the option to tone it down a bit.

So I changed the boost switch around. Now the “boost” setting is what used to be the “normal” setting. There is now the option to add a voltage divider after the tone stack. So, between the gain control, master volume and this, you can control the gain after every triode.

Here is the updated schematic:

This clip is using what is now considered the boosted mode

1 Comment

  1. Hey!
    I love your work and admire your skills,was planning on trying to make something similar to this,
    I’ve got one EL84 I’d like to use for something like this,is it possible to modify this amp to use one EL84 instead of the EL34,of course using an adequate output transformer and power supply 🙂

Leave a Reply