Peavey Session 400 -- looking for layout

[George Biner]

Trying to work on an old, classic Peavey Session 400 (the head unit, not the LTD combo) -- anybody have the layout?

[Jerry Erickson]

I have a schematic, not a parts layout. Let me know if that'll work for you.

[George Biner]

Hey Jerry, I think I'm OK on the schematic. And there is a layout all over the web, but it is smaller and for the combo version.

[Dennis Detweiler]

Brad Sarno should have it.

[Ken Fox]

Check here. Bob Lawrence uploaded my info there. Board layout was not created by me the rest was


https://sites.google.com/site/robertlla ... sion400mod

[Ken Fox]

[Dirk Edwards]

Would it be ok to put two 8 0hm EV's on sessions 400 in parallel?

Thanks Dirk

[Ken Fox]

Yes. That would be a total 4 ohm load
Not only as the main speakers. Amp cannot tolerate a lower impedance.

[Dirk Edwards]

Thank You!!!

[George Biner]

Thanks for the info!

[Dirk Edwards]

I have two session 400 now with black widow 15s.Have you ever heard two 12"EVs in a sessions? Good? Bad?

[Ken Fox]

Those were an option in the first Session 400 amps. Never saw or heard one but I bet they’d sound awesome

[Ken Fox]

Those were an option in the first Session 400 amps. Never saw or heard one but I bet they’d sound awesome

Here’s one for sale. Rare amp

https://www.musiciansfriend.com/amplifi ... -combo-amp

[Lee Baucum]

My first steel guitar amplifier was one of those Session 400s with two 12" EV speakers.
Very heavy. Sounded great.

Speaking of heavy, I sold it and bought a Session 500!

[Dirk Edwards]

That's the one I was looking at

[George Biner]

Thanks, Ken Fox, for posting the layout.

Just wanted to say that the amp (and schematic) I have has a footswitch circuit -- BUT, that layout doesn't have it -- missing the footswitch output terminals and also a transistor and some additional circuitry, plus some component values on the layout are different. Anybody familiar with this version of the amp with no footswitch? Just curious. Ancient history.

(Additionally, the schematic has the main level pot as "master", while the amp itself is labeled "sensitivity". )

The schematic looks to be official Peavey but has no reference designators (R1, R2, etc) for any of the components -- that's pretty wild, never seen that before!