Wednesday, October 21, 2020

ECHOPLEX: EP-3 Preamp, Point to Point Layout

This is one of the first circuits I ever built due to the simplicity, and it's hard to go past as a simple boost with a bit of fattening up of the signal.  

The Echoplex EP-3 preamp doesn't provide tons of gain, but it does work very nicely as a slight boost, or as an always on type effect.   I plan on adapting this to be the front section of a Valve Caster, to provide some extra grit. 

I used the Aion Electronics schematic, as I like the idea of the fat switch, but I did not include the volume control or output buffer.  Pretty easy to add a volume control, I'm sure anyone reading this knows how.  

ECHOPLEX EP-3 PREAMP - POINT TO POINT LAYOUT

ECHOPLEX EP-3 PREAMP - POINT TO POINT LAYOUT
version update:  corrected switch wiring.  pin 2 to ground (thanks Solderholic)




8 comments:

solderholic_JPN said...

Hello Andy.
I made ECHOPLEX_EP-3 Preamp to Klon Centaur Silver Edition by your layout.
Klon Centaur has fat tone on your layout EP-3.
Very COOL!!
I post it to my HP.
http://solderholic.html.xdomain.jp/img/file90.pdf

Andrew said...

That looks really impressive - nice work. Can’t have been easy to make a Klon point to point.

solderholic_JPN said...

Thank you ,Andy!
Dose ep-3 of your layout work good sound by +18V ?
Is 1st pin of fat SW to ground?

Andrew said...

Thank you for spotting that. I've updated the layout, hope this hasn't caused any inconvenience. Pin 2 should go to ground, and the other two pins move to pin 1 and 2.

I haven't played it for a while now - I remember 18v just having more body to it.

solderholic_JPN said...

Thank you ,Andy.
It's meens Fat SW layout is same of Aion schematic.

Andrew said...

Yes, should be the same now. Sorry about that.

solderholic_JPN said...

I've just added 18v charge pump to mymade ep-3 .
it's very powerfull !!
Thank you for your advice.

Andrew said...

No problem - it's a good booster with some tonal colour.