Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Hoffman Turret and Eyelet Boards => Topic started by: EL34 on July 31, 2014, 10:50:19 am

Title: Hoffman AC30 Turret Board
Post by: EL34 on July 31, 2014, 10:50:19 am

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

Layout and Schematic
http://el34world.com/Hoffman/files/Hoffman_AC30.pdf (http://el34world.com/Hoffman/files/Hoffman_AC30.pdf)

BOM - Parts list
http://el34world.com/Hoffman/files/Hoffman_AC30_BOM.pdf (http://el34world.com/Hoffman/files/Hoffman_AC30_BOM.pdf)

Hoffman Board install instructions (http://el34world.com/Hoffman/instructions.htm)

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

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

Title: Re: Hoffman AC30 Turret Board
Post by: jrdworak on August 07, 2014, 02:49:55 am

I've got a Hoffman AC30 board and I'm thinking a 15 watt amp would suit me better. Here's what I plan on changing, please let me know if I'm missing anything.
1. Leave off 2 power tubes and associated parts
2. Use smaller power and output transformers designed for a 15 watt amp
3. Double the resistance on the cathode resistor for the power tubes.
And that's about it, thanks in advance for any help.

Title: Re: Hoffman AC30 Turret Board
Post by: EL34 on August 07, 2014, 05:18:41 am

Yeah,
That's about the only difference between 2 and 4 power tube amps
Maybe fuse size is smaller also


It would be more along the lines of my Stout without the extra gain stage


http://el34world.com/schematics.htm#Hoffman_Stout_ (http://el34world.com/schematics.htm#Hoffman_Stout_)

Title: Re: Hoffman AC30 Turret Board
Post by: pompeiisneaks on July 22, 2015, 01:13:01 pm

I've got a question on this parts list. I just ordered it and didn't notice it doesn't contain a power transformer nor an output transformer.  The others I'd looked at did.  (Should have paid more attention, I know).  What are the recommended transformers for this build that will make it like a vox?  And why weren't they included in the parts list like the others I've seen? 

Title: Re: Hoffman AC30 Turret Board
Post by: EL34 on July 30, 2015, 10:02:34 am

I am ordering the AC30 output and Power transformers and putting them in stock


I'll post back here when I have them in the catalog and ready to go

Title: Re: Hoffman AC30 Turret Board
Post by: pompeiisneaks on July 30, 2015, 01:59:16 pm

Outstanding, I'm thinking I may be ordering them and a few bushings for the chassis holes here after the first of the month as well.

~Phil