2003 MARSHALL JCM 2000 DSL 100
The Marshall JCM 2000 DSL and TSL amplifiers were the successors to the 1990’s JCM 900 series. Featuring true dual and triple channel switching these amps were Marshall’s answer to the Mesa Dual/Triple Rectifier series and the Soldano SLO-100 amps that took over hard rock and metal during the 1990’s. These older DSL’s have an actual spring reverb tank (newer ones have digital reverb) and I think it makes them, amongst other changes, far better sounding then the modern revisions. That being said Marshall cut a lot of corners on these amps and they are filled with under-rated and cheap parts that do not hold up well over time. That is why this amp required the type of restoration I would have to do on a 40-50 year old vintage hand-wired amp after only 21 years. This amp came in with leaking filter caps, heat damaged power resistors, a broken power switch, and blown tubes.
The amp was given a full restoration. All of the radial capacitors in the power filter supply and bias/bypass circuit positions were replaced with new extra high-quality, upgraded temperature and voltage rated electrolytics. Brands used included: Chemi-Con, Nichicon, CE, Panasonic, and Kemet. The under-rated 1 Watt power dropping and bias resistors were upgraded to 3 watt Metal Film and 2 Watt Metal Oxide type units respectively. This was done for better noise floor, reliability, and preventative maintenance.
The amp was completely re-tubed with the following compliment: V1/V4 = EHX 12AX7, V2/V3 = JJ 12AX7S, V5-V8 = JJ E34L Matched Quad. I picked out this lineup specifically for this amp to give the best balance of tone, reliability, and low noise. The adjustable Fixed Bias was set to Factory Spec of Approx. 76mv per pair of E34L tubes. All of the power tube socket PC pins were re-soldered due to stress and cold solder joints present. All pots, switches, and tube sockets were cleaned with De-Oxit and all hardware was tightened. Amp now works correctly - all symptoms were resolved.
