Express with New Pacific Transformers - Modernized Approach

[RJ Guitars]

Hey guys,

I just started an amp this past week to test out the new transformer set that Pacific is winding for me.

It began with one of my project grade chassis with a white powder coat. Look for some modern twists as I'll fill in the details along the way.

rj

[Blind Lemon]

Hey RJ;

Nice to see you building again, I had to take some time off myself. First time I have checked in here in a long time.

Talk to you soon.

Blind Lemon

[Roe]

Looks clean and good RJ. Nice to see you here again!

[RJ Guitars]

More progress... some voltages and another photo or two

TAP -- Unloaded measurement
120V -- 124V
6.3V -- 6.91V
5.0V -- 4.16V
280V -- 309.5V
250V -- 267V

[M Fowler]

Bob,

Very nice chassis I like the can caps and your wiring that up nicely.

Mark

[RJ Guitars]

Thanks Mark. I like the can caps for a variety of reasons, mostly affordability and they really clean-up the wiring a bunch. I will be using a PS board on this one but you don't have to. After I started down this path I thought about it a little... If you mount the dropping string resistors right on the can cap terminals you could use a Dumble style bias board and reduce the clutter a bit more by adding a chassis mounted bias pot. Plus these trannies have that extra 5V tap if you want to do some solid state relays and a footswitch... Lots of good stuff still to be explored. Thanks again. rj

[JazzGuitarGimp]

I really didn't think I'd like the white chassis, but it look really nice.

[RJ Guitars]

The white is kinda classy looking if you don't have a lot of holes to drill after the fact... Not sure if I am all done with them yet. It's really not a traditional Wreck choice... Which was kinda on purpose.

I had to use flathead screws for a lot of the connections and buff off the powder coat where I needed a good ground on the inside of the chassis... Would prefer it only on the outside surfaces for future iterations. I think I would also choose the hammertone gray finish like they use on Komets. Once you see the board set I am working up for this build then it will be clear that I made no attempt to be conventional in how I approached this...

[RJ Guitars]

A little more progress... I added a DPDT switch to allow a quick change between the B+ windings. Also I'll give you a look at my PCB power supply board.

[MCK]

RJ, talk about hitting the ground running!!! Welcome back and glad to hear you are well. That build and the power supply board looks great! You are on the road to bringing the express build process to the masses!!! Keep well!

[M Fowler]

Sweet looking build Bob.

[RJ Guitars]

Progress has been slow... which is my top speed these days, but I did get a few more wires soldered today...

I finished up the wiring on the output transformer. I used another DPDT switch to allow me to use either the 6.6K tap or the 5.2K tap.

I also reveal a look at my PCB preamp board. With this design of the PCB preamp board I haven't deviated much from the traditional layout. If you have never populated a PCB board it can make soldering seem easy... and everything goes together pretty fast as well.

Hopefully I'll get some more done on this soon...

[Colossal]

Really nice!! Looks great!

[jelle]

Awesome!

[M Fowler]

That is a nice clean build rj, really like the new boards and chassis.