1967 Marshall Plexi JMP Bass 50w model # 1986
The Duane Allman amp!
To catch Duane's “Live at the Fillmore” sound your setup would be:
1) a '57 Gibson Les Paul Goldtop, Hot Lanta Burst or a '61 SG (as in later years)
2) a 1967 Marshal 50W model #1986 Bass head
3) Two half open 4x12 Marshall cabs filled with JBL D-120F speakers
4) a Coricidin bottle for slide
This one was sold in the late 60's by Bas v.d. Rest Muziekinstrumenten, Den Haag, The Netherlands. And now back in Den Haag again!!
Bas vd Rest was a legendary music store where the roaring Dutch music scene went to test (and buy) their instruments at full blast in the store!! Some even had a few lessons in the back of the office after the purchase for a couple of weeks.
Originally designed for bass players, many guitarists decided to try these out and noticed that they could get really interesting tones with them. The Bass model was a bit smoother than its Lead counter-part. It could easily be converted into a Lead circuits as well without altering too much to the original circuit.
The 50w Bass spec also has a hair less gain then the Lead version and will sound closer to the legendary JTM45 amp that preceded it! Even though, the 50w Bass packs quite a wallop of power!!!
50 or 100 watt?
Both will be powerful and of course loud. 100 Watt amps can be generally thought of as punchier with a tighter bass response and of course more headroom. 50 watt amps can be thought of as more of a “blended” raw sound when the amps are turned up to distort with its particular tone. It’s a subtle difference between both but sonically they are a tad different. One cannot say that an equivalent 50 watt amp will have more distortion than a 100 so don’t look for more gain to pop out of that 50 watt amp. Also, don’t think that the added two extra tubes in a 100 will cause more distortion. In truth, they are about the same but have a different feel and response.