Panel time. What we have here is a reverse engraved gold plexi panel, hot off the laser.
Lets just keep rolling on this… Rogers' amp!!
This is the circuit card in progress.. here I am attaching the leads before putting the card into the chassis.
I use a harness jig for the production model amps. They all start off like this when I am in R&D, paying out the leads over length…. But once I get the amplifier lead dress performing to my liking I remove the board from the built proto amp and build a jig to copy the lead lengths for each wire. This method leads to consistent performance from amp to amp.
Lead dress is where you bring the amp to life. Done right, proper lead dress can be like tuning a racing engine. Its just not going to run right until this is perfect. When its perfect it can create small feedback loops that help the amp reject bad frequencies and reinforce the good ones. This also requires dog like hearing to accomplish. ARF!!!!
Stay tuned for more...
Progress continues on the Rogers amp…
Transformers are attached as well as the sockets and can capacitors. The reason for the output transformers position is magnetic. This is the position that allowed for the lowest coupling between the power and output transformers on this chassis given the other variables of component placement.
I have I method for determining the positions of the various components with which could fill another book, but again I would rather build. Lets just say that all the components in an amplifier form a kind of "electrosphere" that can work for or against the designers goals. My goal is to make a circuit whose design is symbiotic.
This is the black art that eludes many builders. -Ossie
Well hope y'all had a good 4h!!
The Rogers Project continues…
Here we have the circuit card with eyelets installed. Each one is inserted by hand and set using a staking tool and hammer.. takes about 10 min…..
Next we have the near finished circuit board. Note the different caps and resistor types. I have a method to my madness, and yes it works. A combination of old and new precisely chosen for its specific application. There are many reasons to choose a part, I could write a book on this but I would rather build instead. -Ossie
Meanwhile Sam cuts a 1-12 cab logo to size… wonder what it will go on??? More to come!
Using this jig a standard 3 Monkeys chassis is modified to accept a laydown power transformer…. Yes thats a Porter-Cable and it cuts through the aluminum chassis like butter...
While Ossie and Sam work on the physical amp at the shop in Raleigh. Greg works on the panel creation while on the road with Brad and Aerosmith.
It all starts here. The brain of the amplifier.
Most guitar players/ techs know the similarities between early Fender and Marshall amplifiers, esp the Bassman.
Here we have the original master template for the 63 Splitfront from the Blockhead era of my life.
Yes it is the same one I used to make all those sweet Splitfronts more than 15 years ago… I cut a board out of paper grade phenolic sheet, and drill it out on the press. Eyelets will be inserted following this process.
We are going to modify the parts list a little to fit more closely the early Bassman circuit. An early JTM45 is essentially a Bassman, we just need to change a few parts values and we will get what we want.
Rogers has much love for these great amplifiers, … They often sound the way you wish your plexi did ;) This fact is not lost on him.
Stay tuned for more, gotta get back to work!
And so it begins!!! Our good friend Rogers Stevens just sent out the call to action!
The original, only, and current guitar player for Blind Melon requires a new weapon and I aim to make it for him. Rogers is a fantastic guitar player and I am honored to be working with him again!
Its going to be a one off -Watch and see what we come up with… Right here !!!!
Ps ----- He also snagged a Nashville Howler pre pro on monday to put it through its paces. Could be quite useful in his studio… Ya think?