These two amps have become my favorites! I have owned just about every Marshall ever made...except the original Plexi/Bassman... After roughly 15 years of buying, using, and selling 800s, 900s, Jubes, JVM, DSLs I keep coming back to these amps. These two DSL 100s were made in the year 2000. I have replaced both transformers and added a choke. Power transformer is Classictone, output transformer is specially made by Heyboer. Choke is a 3H 250mA Heyboer. Tubes are original Svelanta Winged Cs and a collection of GE, RFT and Raytheon preamp tubes. One of the amp's I replaced the mainboard with the Marshall upgrade...not because it needed it, but because to be safe...I replaced it anyway. I am going to replace the other one as well next month... however, it too works perfectly. These amps are tone bombs! They deliver honest Marshall vibe in spades man... I have a 2204 that I love to death...it's from 86', but I prefer these amps man...for gigging...insane. They sound better and more importantly, FUNCTION better then any other Marshall I've ever owned. All said I probably got about a grand into the heads each. But I will NEVER sell them.. well until I can't play anymore... in which will see me croaking shortly thereafter...when that occurs.