Hi David,

Thank you for contacting Mearto with your appraisal inquiry.

The Marshall JMP 4150 (often branded as the "Club and Country Bass" model) was one of Marshall’s rarer bass combos from the late 1970s and part of a small line of Marshall bass models from that period before Marshall largely exited dedicated bass amplification in favor of guitar amps and later hybrid/solid‑state bass series.

There just weren’t many bass combos from Marshall in that period, so surviving 4150 units show up less often than classic guitar JMPs.
Condition is considered crucial since these amps are 40+ years old and valves, caps, and speakers wear with age and use and often require frequent servicing.

I've found a few different "good condition" examples of this model retailing currently for between $1,500 and $3,000 but when these come to auction, they usually don't bring that much - usually between $700 and $1,000.

Please let us know if you have additional items to appraise, or questions/concerns, and thank you again for using Mearto.
~ Delia