Hoffman Plexi 50

[lego4040]

Wow its been a long time but I'm in the mood for a Marshall. I went back to pedal building to finish up most of my half built boards taking up space on my desk   In the process I realized I missed amp building. I love the look off the offset Marshall JTM45 but I want the EL34 sound again cause I love my Vox AC 15 build. I'm gonna go with Dougs Plexi 50 here but I was wondering what year and model this is designed after? I might want to use different transformers then what is here and I wanted to be able to refer back to a year and model # for specs. If I can build this in a offset chassis that Mojotone has I will go that route but I havent compared chassis dimensions yet. I hope everyone has been doing well and Ill be around for awhile, my eyes cant handle those small pedal builds anymore. Cheers

[sluckey]

Doug's Plexi 50 is based on the JMP series model 1987 Lead 50 watts.

     http://el34world.com/charts/Schematics/files/marshall/Marshall_jmp_lead_50w_1987.pdf

[lego4040]

Thanks Sluckey, I printed out that schematic and another the other day to compare. I have two amps, no three amps on my plate I wanted to get rolling. My wife got tired of looking at all the pedals that started accumulating in front of the tremulox😬. I really love the way the JTM45 offset head looks and Im trying to figure out if I can build Dougs Plexi in it. Anyway, Im still rocking your Vox design and loving it

[lego4040]

If I didn't want to use the PT that's linked in the the parts here(its a stand up) and Id like to use the lay down. Is there one here that's suitable? I'm looking at triode electronics to try and match up http://www.classictone.net/40-18089.pdf   http://www.classictone.net/40-18054.pdf.  Also why the 3H choke and not the Marshall style 3H? If been reading up on these 50 watt plexi and see they've gone thru some changes early on, I seen some people had installed 10H instead. I understand its filtering and that the 10H had tightened up the lower end at higher volume levels.

[sluckey]

I would use Doug's PT for Super Reverb. But why don't you want a stand up PT? I much prefer standup PTs for looks and ease of installation.

[lego4040]

I didnt even think to look at using fender pt’s, it is a bassman circuit anyway. Doug doesnt carry the plexi chassis and I didnt want to punch a chassis this time around, since we were last conversing when I was building your AC15 and Revibe I had moved to a different HVAC plant, I have drill press and stuff but I was looking for quicker chassis build. I always know Someone here has info and helps out.

[sluckey]

You need to look at mojo. They have a nice looking offset head cab. They also sell chassis, transformers that fit those chassis, or even complete kits. Most of this will fit their offset chassis.

Doug can sell the mojo stuff, maybe even with a price break, especially if it's a drop ship order. So, look at mojo, firm up what you want, and send a pm to Doug. You may get lucky.

[lego4040]

Yes that offset cabinet is gorgeous and what I want and hope to use. I was planning on ordering the chassis w turned in edges from Mojo and then ordering whatever else I can from Doug. I want to give my $$$$
to the people who do the right thing with their clients.

[svejkist]

I would use Doug's PT for Super Reverb. But why don't you want a stand up PT? I much prefer standup PTs for looks and ease of installation.

And space management. I build inside old SS Peavey combos. Very cost effective, but it can be easy to run out of chassis real estate. Thank you Weber for selling stand up end bells.