I have alwasy been a fan of mesa boogie . I guess alot of inspiration was for my small town guitar teacher in middle of nowhere town in china who taught me alot of Metallica riffs. In Fact, My very first pedal was a Dr.Boogeyman from a shop call doublefish. I lost the pedal sometime in junior high, but after 10 years of busy work/study i contacted the same shop and they re-made the pedal just like the one i had
Anyway, recently I begin comtemplating a DIY project one day when browing Bane's website about a Mark 2C+ build http://diy-fever.com/amps/mesa-mark-iic-pcb/ . For my Background I graduated with a Electrical Engineering bachlor degree from Arizona in U.S, but I feel like I didn't nearly have enough knowledge about the tube amplification.
So I dived into Youtube University and begain to learn as much I can about this special Subject. Thanks for many of the amazing Youtube Channel(s) like @UncleDoug, @BlueGlow Electronics and Aaron Lanterman's( channel(@Lantertronic) . I learned alot about the In-and -Out about tube amplification.
Since I 'm currently residing in China it's quite easy to have a PCB made by a manifacturer, therefore I had a PCB board(s) made with Gerber file.
from send in the design to receive the board in less than a week..... pretty speedy
I want to see if I can build this preamp small enough that could fit into a Aluminum case of 300mm x200 mm x 65mm (11.8 x 7.8 x 2.55 inches) to potentially fit on to a pedal board. well in the end it took alot more effort than i expected to work in a small space
For example, until I was about to closing the case I realized the Potentiometers are too big to fit in there. I had to change to smaller 16mm diameter pots.
I used a little a little Power Supply module ( the metal case on the right 85 x 55 x31 mm) that provide a 320V DC @0.2a and 13V DC @3A. Therefore the tube Filament supply is in DC.
For the Capacitor I have tried to use as much from CDE / sprague Orange drop as I can. hower due to the Limited Space I was not able to fit in the big motor starter capacitor for on the power supply side. therefore I have to stuck with electrolytic capacitors.
For tubes I use 3 x ECC83 from JJ Electronics
Finally finished! spent some quite some time debugging but no big problem. In the end I realize I need to improving my wiring skill to use shorter wire. but fortunately the amp is works pretty well and noise is suprisingly low.
After putting the preamp to test, I do feel like it kind of need to go through a EQ pedal and scoope out the mid to generate the Metallica Sound, just like the original amp . I have a Mesa Boogie EQ pedal. But I also tried it on my Joyo 10 band Equalizer and it work out pretty well as well.
Below is the Mark 2C+ preamp along with my DIY poweramp that provide a clean platform for testing, the cabinent is a 2 X 12 Celestion V30 speakers. I will make a Youtube video very soon.
Later on I went to PCB document and optimized a few places on the board in alituim to have the 12AX7 PCB sockets fit nicely on to the board, and add some wiring on the PCB design to have less hand work later on. I will make a another more detail post about it if this circuit board works. Overall I think it consolidate the design and will reduce 60% of the soldering work.
the side by side comparison between the first board (yellow) and V2.0 ( Purple)
