Hoffman Plexi50 Turret Board

[EL34]

The layout Diagram, Schematic and BOM and other build information can be found on the library page here
http://el34world.com/schematics.htm

Layout and Schematic
http://el34world.com/Hoffman/files/Hoffman_Plexi50.pdf

BOM - Parts list
http://el34world.com/Hoffman/files/Hoffman_Plexi50_BOM.pdf

Hoffman Board install instructions

Hoffman Turret Boards are on this page
http://hoffmanamps.com/MyStore/catalog/TurretBoard.htm

Hoffman amps Public parts list page is here
http://hoffmanamps.com/MyStore/catalog/PartsListIndex.htm

Plexi 50 demo tunes

Beck's Bolero
http://el34world.com/Misc/Music/files/Plexi50Demo3.mp3

I got the Six - ZZ top
http://el34world.com/Misc/Music/files/IGottheSixPlexi50.mp3

Cause we've ended as lovers
http://el34world.com/Misc/Music/files/CauseWeveEndedasLoversPlexi50.mp3

[EL34]

I just updated the Hoffman Plexi 50 Layout and schematic with a couple new pages.
The two new pages has my Hot Switch mod schematic and layout


Here's the link
http://el34world.com/Hoffman/files/Hoffman_Plexi50.pdf

[taylorc315]

Can someone please post a picture of a completed 50 plexi turret board, or direct me to one. I'm just getting started in this and would love to compare to make sure I have it right before I commit to soldering.
Thanks
Tracy

[EL34]

That may be tough.

I hardly ever sell Plexi boards.
Everyone seems to like the smaller amps these days.

I sell lots of Fender type boards, especially Princeton AA1164's, 5F1 Champs and 5F2A Princeton's
Also lots of the small 18 watt Stout and 6V6 plexi boards

I have not build a 50 Plexi for many years because I have the original one I built in 1992

The layout diagram is just like looking at a real board
That's why I spent so much time doing those diagrams
Looking at someones board is not very useful because you can't see where all the wires go and some people do not do very neat builds

[taylorc315]

Thank You, I should be ok but I see that the schematic has 2 500p one paired up with the 470 on the ninth lug, and one by itself on the 12th. the kit only calls for one 500p and that's all I got, do I need to get another?

Tracy

[taylorc315]

Also I do have a 1972 50watt head that's pretty much original, I suppose I could open it up and compare. don't know if that will help.

[EL34]

Thanks for the heads up
The parts list is supposed to have two of those 500p caps
I fixed the parts list


The 500p across the 470k makes that channel brighter.
You can leave that off if you do not want a really bright channel


The other 500p is the tone control section treble cap

[taylorc315]

Thank You You've been a tremendous help!

Tracy

[taylorc315]

Hello,
Could you give some insight on the wires that come with the kit? The kit comes with red,black,green,white solid wires. Also it comes with stranded of the same, but the diagram only shows using the red and black mostly. Any info would be great as this is my first amp build.

Thanks
Tracy

[EL34]

The wires that come with the boards are just a generic wiring kit
There's no way to tell what colors someone may like to use or not use and so I include a little bit of each


Have a look at the Board installation document on the library page
It's has wire color suggestionsThe link is right below every Turret board on that page

[taylorc315]

Thank you very much!

[EL34]

Found this video on you tube with a demo of one of my old Plexi 50 watt heads and a Hoffman reverb unit

https://www.youtube.com/watch?v=snHgRgyWLfQ