Fender 5e3 Tweed Deluxe clone 'Marsha'
written up 2020-6-20
Built late 2016
The goal was to make a tube amp from near scratch, without buying a kit, as cheaply as possible with local parts where available, especially for the power supply. I really wanted to avoid buying an actual fender deluxe power transformer and fender output transformer, so probably the most interesting & unique aspect of this amp is the power section, and with the output transformer an Australian sourced item that has been well documented in Australian home brew valve amp circles (ie https://ozvalveamps.org/optrans.htm )
The cabinet, chassis & speaker is from a gutted Marshall Master Lead Combo, which was a solid state amp from the 80s or 90s, which I bought off Gumtree for $80. I gutted it and sold the guts on ebay for $20.
The amp circuit is a straight up 5e3 but with the master volume mod as described here on Rob Robinette's site - master vol is a 1m pot in place of the 1m resistor feeding into the phase splitter.
The layout is point to point & based on the original. The mounting board is just a piece of masonite and the eyelets I had to buy from overseas. Most passives are from Jaycar while the high voltage power filter caps are from Evatco.
The 6v6 are a supposedly matched pair of NOS eastern European tubes that I got from ebay. It also has some random 12ax7's I either pulled out of something else or bought. (I know v1 is meant to be 12ay7 and I plan on replacing that.)
Output transformer is a 20w Altronics M1120 for $19 - and that is fully documented here. The whole thing cost me about $250 AUD.
Power section is two Jaycar 24v transformers back to back. So 240AC in -> 24AC ->240 AC which rectified (using a straight up bridge rectifier package) gives about 342v dc for the B+ unloaded, 292 loaded)- which is a little low (meant to be 370v loaded?) but I don't mind it running a little brown (and neither did EVH).
Heaters run off their own transformer which is an Altronics M2152 12.5v.
I did put a standby switch in it but later deleted it, because who needs them, really.
It sounds fine, and the channel volume knobs are very interactive. I had more fun building it than anything though and it was a very worthwhile project.
References
Rob Robinette's 5e3 page has tons of info including how it works & all the mods you can think of.
https://robrobinette.com/How_The_5E3_Deluxe_Works.htm
Oz Valve Amps page on locally sourceable output transformers
https://ozvalveamps.org/optrans.htm