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[EL34]

This board has information on the Hoffman Turret boards and projects of mine

This is a list of Hoffman Turret boards
5F1 Tweed Champ Layout, Schematic and BOM
5F2A Princeton Layout, Schematic and BOM
5E3 Tweed Deluxe Layout, Schematic and BOM
5F6A Bassman Layout, Schematic and BOM
6G15 Reverb Unit Layout, , Schematic and BOM
AB763 1 Channel Layout, Schematic and BOM - Thanks to Steve for the original schematic drawing
AB763 2 Channel Layout, Schematic and BOM - Thanks to Steve for the original schematic drawing
AC30 Layout, Schematic and BOM
Plexi 50 Layout, Schematic and BOM
Princeton Reverb Layout, Schematic and BOM - Thanks to Steve for the original schematic drawing
Stout Layout, Schematic and BOM
Stout Reverb Layout, Schematic and BOM
ReVibe Layout, Schematic and BOM

Here's a sample file showing the AB763 2 channel board
http://el34world.com/Hoffman/files/Hoffman_AB763_2.pdf

All the Layouts, Schematics and BOM's can be found on the library page here
http://el34world.com/schematics.htm

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

Make sure you view this file that explains many things on my layout diagrams
http://el34world.com/Hoffman/files/CommonHookups.pdf


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

An Important Note
Go here o read on how to make sure you are getting the most recent PDF file
http://el34world.com/Forum/index.php?topic=17468.0

[EL34]

Question: How do you connect the Ground Buss that goes down the back of the pots?
Answer: You don't
The ground buss is soldered to the back of the pots
The pots are bolted down to the chassis
The chassis is made of metal
The ground connection from the pots to the Power transformer lug is made through the chassis
See the image down below

Question: How come the 5E3 and 5F6A diagrams have separate cathode resistors and caps on the first preamp tube? The original schematics shows that both tube halves share the same resistor and capacitor
Answer: This lets you voice each half of the pre-amp tube differently if you want to. If not, just do it like the original. You have that option

Question: There are no input grid resistors on the original schematic for the power tubes. How come your layout has them?
Answer: It's best practice to use grid stopper resistors

Question: Your bias system is different than the one on the original schematic
Answer: I use a more stable bias system than some of the original amps had. It's a better system. I also add bias pots if there was not a bias pot on the original amp.

Question: How come there are one ohm resistors on the cathodes of the power tubes on some of your layout diagrams?
Answer: This makes it easy for you to bias the power tubes. What's not to like about that?

Question: Why do grid stopper resistors go to pin 6 on the diagrams. Pin 5 is the input grid
Answer: Pin 6 is not used internally on 6L6's and EL34's. It is just used as a handy solder terminal for the grid stopper resistors. The same goes for EL84's. Pin 1 is not used internally on an EL84.

Question: How come you only show one input jack with a 33k resistor on the layout diagram and schematics?
Answer: Most people never use the Lo jack and so to keep things simple, I show an easier and simpler way to create an input jack. The diagrams also show how to set up a Hi-Lo set of jacks if you prefer to do yours that way

[EL34]

Future use

[EL34]

future use