Rare 1978 "Rock 'n Roll Baby" 100 watt combo (Superlead) with PPIMV (Post Phase Inverter Master Volume) and new Electro Harmonix EL34 valves (4) and three new 12AX7 valves from Tube Amp Doctor (Germany). Recapped with new audio / filter caps from Tube Amp Doctor. Upgraded with vintage Electro Voice EVM12L (8 ohm) 100 watt speaker worth €200. (Happily the the factory supplied Powercell 100W speaker is gone.) (EV12L are the speakers used by Mesa Boogie. Marshall and Electro Voice EVM12L is the Holy Grail combination for UK vintage blues rock sound. This is an exceptionally rare amplifier which has been upgraded to modern specification. It is heavy (as in 31.3 kilogrammes). Four inputs (2 bright and 2 normal) . Very rare amplifier, only 400 2150s ever made, few of those will sound as good as this one. Has external speaker output jackplug for speaker cabinet up to 16 ohms so can be used as a Marshall Head (Marshall heads from this era cost €2000 or more). Sticker reads "Crowley's Cork 53426". This amp has a lot of gain and power, would suit a hard rock/metal player with Les Paul style input. Sounds best with both channels jumpered. Jumper cable included. Easy distortion break up but compression is good and the EVM12L keeps it smooth. Bright signal and normal. Recently professionally re-biased and serviced. Comes with three free EL-34 Valves worth €90. Small tear to Tolex at front. Small signs of wear and tear. Otherwise good appearance. Audio sample: https://www.dropbox.com/s/hity012fjtg2m95/SeemADream09.mp3

https://drive.google.com/file/d/17LQsaJQl9yW-xmD6Fxv8fIHKvihixIqf/view?usp=sharing

The amp was stored for most of its lifetime. I gigged with it less than 10 times since 1993, so it has been well looked after. I believe the value of these amps is underrated. The problem was at the time of manufacture buyers preferred Marshall heads and cabinets to the combined unit. That is why only 400 of these amps were made. (). This makes them extremely rare, especially in the USA.
If you are looking for more gain then try a Super Lead but a Super Lead Marshalls from 1978 are really expensive and are the premium collected Marshall amplifiers. However you can easily convert a 2150 into a Marshall Super Lead (Hendrix) by halving the resistors at R12 and R15 on the schematic. The mod is ill advised however because the 2150 amplifiers are so rare (especially in USA) that collectors prefer them in stock condition. The Celestion Powercell speaker is long gone and I replaced it with a an EVM-12L from the same era, which is a definite improvement. The amplifier has been recapped but that does not affect the vintage collector value. The old Daly filter caps are gone and have been replaced with Tube Amp Doctor equivalents electrolytic capacitors. The improvement in tone was noticable. Here is a good link to start your research https://www.marshallforum.com/threads/marshall-2150-conversion-to-super-lead.98665/