Silverface Champ - new sounds

[angelodp]

So this is a bit of an experiment, I am sure it's been done somewhere. It's a 70's Silverface Champ.

I simply want to up the output a bit and give myself some tonal options and it needs to be reversible.

1. New WHS 8" w/ Ceramic magnet

2. Swap out the 100k plate R's for 220k

3. Up the 12ax7 CR to 3.3k

4. Up the 220K near the 47ohm to 560K

5. Cathode bias R on 6V6 up the 680K - Cap to 100uf 50v

6. Install NFB switch on underside of chassis (on - off). Thats the only non-reversible element.... the small hole.

7. Remove the lo-input jack and install a 250KA push pull pot. Run the Bass ground leg to the 250KA pot wiper, ground tab
to 6.2k the to ground. So it's kind of a MID/RAW pot.

8. The push pull gets used to allow a 120pf bright cap for low volume.

9. Its running 15W at 120v and 13W at 110

10. New F&T caps all around


All in all it is quite good and I dig the tonal options. Its a tad more gain for sure, breakup at 6-7

Cheers A