'Lo all! I'm going to be taking my fist stab at amp modding with my Ceriatone TMB. I've gone back and forth with Nik (what a great guy!) and with his advice I feel prepared to move forward. First of all, I love the amp. My goals are to make the volume and tone controls more usable, to get a little more clean headroom, and to have the master affect both channels. Here is the layout from Ceriatone: http://ceriatone.com/images/layoutPic/marshallLayout/TMBceriatone.jpg And here is what I plan to do to it: http://img517.imageshack.us/img517/5486/moddedtmblayouttm8.jpg For the resistor change Nik said I could use the regular concrete type, but I found some NOS ones at Torres, so I'm going with that. The replacement pots are CTS, also from Torres. If it turns out not as good as it was, they are all easily reversible mods. I'll post up how it turns out once I get it done!
My modded Cer. TMB is my go-to amp. Many other amps have come and gone but this one is my "goldi locks".......just right. There are a few mods on your layout I haven't tried so I am very....um....... interested in your results. I haven't checked in to 18watt.com in a few days..have you posted your ideas for review over there? If you don't mind please do one mod at a time and document your findings. I love all things 18watt.
I haven't posted at 18watt yet, I need to do that. I'll be doing one thing at a time and checking to make sure I haven't jacked it up, as well as documenting my findings. What did you do to yours?
Oh, a few things....lol. Some of these have been changed back to original values. -Power cathode bypass filter to 50uf then to 100uf -120pf bright cap across volume lugs - 220k2W bleed resistor across cap can (not a mod) -C1 coupling cap (v1) to .0047uf -33k/500pf slope/treble bypass combination (I did a lot of combination testing and I like this balance) -V1 cathode caps to .68uf -R9 PI bias resistor changed to 2.7K (cold bias) then back to 820 -120pf cap across the PI plates -V3 tail resistor to 47k then back to 56K -Ironsounds buffered loop installed (removed) -Sozo caps in most positions -Kiwame resistors in positions other than plates This amp now has plenty of clean, beautiful headroom and the inherent boominess of the circuit is in check. Great amp.
I really like the idea of the master volume controlling both channels. Was that done with just simple rewiring, or did you need extra parts? It looks like all you had to do was change 3 wires? Are you happy with how it works?
