I bought a used DSL1 a few months ago for $230 total. Removed the chassis to investigate what was inside. I noticed that the output transformer had an unused wire inside that was tie wrapped in the wire bundle. After ohming it out I decided that it has to be an 8 ohm tap. The only output is 16 ohms. With these small one watt amps, it is ok to mismatch output impedance without damaging the amp. I read that one of the marshall designers did that with one of the 50th anniversary models to get better tone. I added another output jack next to the 16 ohm jack. When wiring it up, I found that marshall had swapped the ground and hot on the pcb spade connection. So I swapped them and wired in the new lead. I recall that it was white. With a meter I read 1.6 ohms on the 16 ohm output and .9 ohms on the unused lead that I assume is 8 ohms. I set up my DSL1 using the new 8 ohm output that I installed. Cabinet is a lead 12 slant fitted with an 8 ohm 12" celestion vintage 30. I also swapped out the stock ECC82 power tube with an RFI ECC82. Amp sounded incredible! Then I switched the 8 ohm speaker to the factory 16 ohm output and it did not sound as good. So I can see this mod as being a good thing for those with 8 ohm cabinets.