Fender Vibro-Champ w/o vibro build - OT hook up & review please

[RoadShow]

Hi folks,

I wanted to build a Fender Vibro-Champ w/o the vibro and "think" I've drawn the circuit correctly.  Could you please review and give me comments?

In particular, it seems the Hammond 1760C is the right fit per their website, and to match the OT to the 6V6 I would hook up the blue & red, correct?  If so, what's the proper way to tie off the 5k brown wire?  Cut it short, heat shrink the end, and tape it to the chassis?

Thanks for your inputs!!!

[exnihilfit]

why not use the Champ AA764 schematic/Layout?
https://el34world.com/charts/Schematics/files/Fender/Fender_champ_aa764_schematic.pdf

For the 5K lead on the transformer, I usually just shrink wrap the end and then loop together and use a larger shrink wrap for the rest of the lead to make it a stub, I don't like to cut in case I may use it in the future...

[dogburn]

Yep, that transformer works, but you also might consider the Hammond 1760CP, which has a 4 Ohm tap rather than 3.2 Ohm, since new 3.2 Ohm speakers aren't common (but it's a minor difference anyway).

And I put heat shrink on the end of the unused wire, roll it up and secure it with a zip tie and tuck it out of the way.

[dogburn]

I built a no-trem Champ (the AA764, as exnihilfit pointed out), and added a NFB switch, which is a really useful mod if you are looking for additional tweaks to the circuit. I also add a mid/raw pot (from Rob Robinette's site) to give more tonal flexibility that can send the sound into more tweed territory.

[RoadShow]

why not use the Champ AA764 schematic/Layout?
https://el34world.com/charts/Schematics/files/Fender/Fender_champ_aa764_schematic.pdf

For the 5K lead on the transformer, I usually just shrink wrap the end and then loop together and use a larger shrink wrap for the rest of the lead to make it a stub, I don't like to cut in case I may use it in the future...

Yep, that's exactly what it is.
Thanks

[RoadShow]

Yep, that transformer works, but you also might consider the Hammond 1760CP, which has a 4 Ohm tap rather than 3.2 Ohm, since new 3.2 Ohm speakers aren't common (but it's a minor difference anyway).

I built a no-trem Champ (the AA764, as exnihilfit pointed out), and added a NFB switch, which is a really useful mod if you are looking for additional tweaks to the circuit. I also add a mid/raw pot (from Rob Robinette's site) to give more tonal flexibility that can send the sound into more tweed territory.

1760CP, yes, but the 1760C has 8 & 16 ohm options, CP doesn't have 16.

What resistors did you use for NFB switch?  For the AB763 example he uses 820/1.5k whereas the Champ starts with 2.7k.

Thanks

[RoadShow]

Updated schematic...

[dogburn]

I just used the standard resistor for NFB and added a switch to cut it out of the circuit. You could do a three-way switch with two different resistor values plus cutting it out, but I haven't found that as useful as a simple NFB/no NFB switch.