(25/1/2000) The Toaster has now been finished and running for almost a month. Nothing has gone wrong with it yet, but I won't consider it truly complete until it has survived a 3-hour jam session at full blast. Then the name badge can go on.
There have been a few minor changes to the circuitry, and a simple transistor protection circuit has been added to the power stage. It shuts off the HT in case of excess screen current, or loss of grid bias.
On the hardware side it now lives in a nice custom 19" rack, fan cooled, with all the tubes shock mounted.
(10/6/2000) Got some Russian 6L6GCs to use as spares. Liked the tone so much I now keep the original 6CA7s as spares. Bolted on some rubber feet to stop it scratching the furniture. It has now survived three 3-hour jams at earplug volume as well as daily practice (at less than earplug)
(Winter 2000) Found out I was low on power with 6L6s- only 30 watts! Investigated and found 360V screen voltage was too low for them. Increased it to 475 by connecting screens to plate supply. Now 6L6s worked OK, but EL34 screens glow white-hot. Fire in the hall, John! Solved problem by adding an itty-bitty switch to select high or low screen voltage. Can never decide which tube type sounds better.
(Feb 2001) University throwing out piles of tube equipment. Quickly removed all tubes and wandered corridors with shit-eating grin and labcoat pockets bulging. Prize haul: A pair of RCA black-plate 6L6! In the toaster they go that very evening! The glass glows blue, indicating that they are practically unused, and soon the neighbours' ears are glowing a furious red.
(Spring 2001) Toaster started crackling for no apparent reason. Swapped preamp tubes to no avail. Took amp to bits and bonged innards while listening to speaker. Finally found the ultimate dry joint: a connection I'd forgotten to solder at all. D'oh! At last, got round to painting the 'asylum green' rack ears in a sensible shade of black.
(30/4/2001) This amp rocks
(28/7/01) It still rocks
(05/08/02) The BOOST knob doesn't work properly. It crackles when you turn it. I replaced it with an 8-way rotary switch I had lying about, and 8 resistors. Also I found out there is an amp called the TOASTER already... bummer... for those of you who are interested it's a practice amp made by MATAMP (http://www.matamp.co.uk)
(9/11/03) It still rocks