Hoffman vs RobRob 5f6a layout

[LPJr]

Hi all- I’m just starting my first 5f6a build (only my second after a 5e3 kit)
I have a turret board that matches the Rob Rob layout and I’m ready to start populating the board, but I purchased the Hoffman parts list and now I see layout is quite different, and also some circuit differences in cap and resistor values. Most notably Hoffman calls for 5 doghouse filter caps and RobR only has 4.... also Hoffman bumped up the bias filter caps for 8uf to 10, and added the bias trim pit which looks like a good idea. Can I just use 4 filter caps and the other Hoffman values with the Rob R layout? Why does Hoffman use 5? TIA

[sluckey]

Hoffman bumped up the bias filter caps for 8uf to 10

No big deal.

Hoffman uses five 22µF filter caps because Fender used five 20µF caps. But notice the first two caps are parallel. A single 40µF would work just as well. Perhaps Rob used a single 47µF for the first filter cap? I can't confirm because Rob's website is down.

Disregard the above paragraph. I found Rob's layout. There are a total of 5 filter caps in the original, four 20µF in the doghouse and one 8µF on the board. Rob did his layout the same. Hoffman chose to use five 22µF caps. He can probably tell you why he used a 22µF rather than a 8µF.

[LPJr]

Thanks Sluckey, yes RobR has 4 22/500 (and monotone has 4 20uf)
The old Fender layout doesn’t show the cab board but I only see 4 20/600 on the schematic unless I’m missing #5? I’m new to all this and still learning how to read these layouts and schematics, but in my searching around I’ve only seen Hoffman’s with 5... please educate me!

[LPJr]

Ok great thanks... I guess I’ll just save a few bucks and stick with this board then and just use the 22 on the board- sorry about getting two threads going I’m new to the form m didn’t know if it would get seen on the old one...I’ll stick with this one now. Also when I ordered the 10uf bias caps were out of stock, so should I get 8uf or go with Hoffman’s increased values?

[LPJr]

On second thought after staring at these layouts for a while I’m taking Sluckey’s advice on the other thread and just ordered up the Hoffman turret board- just looks so much tidier and well thought out. I also like the idea of almost no wires under the board. Thanks again.

[sluckey]

The old Fender layout doesn’t show the cab board but I only see 4 20/600 on the schematic unless I’m missing #5?

Like I just said above, the fifth filter cap is an 8µF and it's in plain view on Rob's documents and the original Fender board layout/schematic. See attachment.

Hoffman most likely chose to use a 22µF for the fifth cap because it gives improved filtering. I strongly suggest you quit looking at Hoffman's documents. Just use the original Fender docs and Rob's docs, or whoever you bought the board from. Otherwise you will be very frustrated before you finish this project.

[EL34]

Use the layout for the board you have

If you are using my 5F6A turret board, you use my layout and install instructions