I haven’t had as much time to play with my amp as I’d have liked this week, but I have managed some tweaking. I’ve tried a few options for the caps in the tone stack and added a ‘bright switch’ cap across the volume pot. I’m astounded by how much of an effect a small change can make to the overall tone (also, I now understand ‘icepick’ highs... ouch). I’ve still got a bit of playing to do to find exactly the sound that I want but that’s part of the fun.
I must say that the blackface/brownface and -ve feedback switching are both a little too subtle at this stage. Once I’ve got my main amp right I’ll turn my attention to accentuating those options… The raw switch on the other hand is immense, it really is a fantastic party trick.
One thing that I have noticed though is that I’m not managing to get a great clean sound at any real volume at the moment. I suspect that one of my tweaks has affected the drive but I’m going to need to play to figure it out. It may be as simple as the bias being out or the old output tubes breaking up earlier than I expected. I’m really hoping that it’s not the output transformer… but that doesn’t feel likely.
I’ve also built the attenuators. Working in that confined space was… not easy… but I got it all in and it all works. I don't think that I won’t do it this way again. The -3dB and -6dB settings only give the smallest of volume drops and even the -10dB doesn’t really allow for bedroom level playing of the driven amp. I’m pretty glad that I didn’t bother with the caps because I didn’t notice any significant treble loss in my brief tests last night.
I will be making an external I-Pad attenuator at some point and it’ll be interesting to see how they interact.
I still have some tweaking to do on what I have already built to get it where I want it but now that the attenuator is installed I’m starting to think about the next phase. I still have a large amount of open space in this chassis, on the side furthest away from the power supply. I could easily put in three new tubes and 3 or 4 pots/switches if I get clever.
So I’m toying with a few options.
1) Get a reverb tank and add a reverb circuit (eek)
2) Add a tremolo channel similar to the original blackfaces
3) Branch out and add a modern lead channel
4) Shoot for a classic one two and add an old school plexi style channel
What do you think? Which of these sounds cool? Can you think of any other options to explore?