On the Book of Fakes, in the JMP group, I've heard of people parting out 1959 Organ versions to keep Leads alive. I have yet to actually see an Organ version. If you have one, can you please post some photos of it, front and (especially) the back? I want the info in case I need to duplicate an Organ model specific back panel at some point. I'd kind of like to get an Organ version just to add to the collection. In ANY condition.
There’s no such thing as a 100w Organ version. The 50w standard range always had an organ variant until about 1973/4. It was the same as a bass model but with a bright capacitor on channel 1 volume.
There was obviously a lot less made than either bass or lead models. That said, I saw them fairly often for sale in the UK 5 - 10 years ago and were less desirable than the lead models. My guess is that they were bought and converted to lead models or modded in some other way.
The difference between an organ and a bass amp is just the bright cap. And it’s a lower value cap than a lead. I’ve recently owned a 4 hole PA and organ. Before the split v1 cathode there was very very little difference between the lead, organ and bass models....check the schematics. If you want an organ, just get a bass model, write organ on the inspection tag and pretend a previous owner clipped the bright cap, lol. Edit: I’m talking 50 watters only. Sorry I don’t do large box heads.
Seems to me either my organ or PA came without a mixer bypass cap. Maybe someone knows if that was a thing or just mine.
I've never seen an organ model before but I've seen the smaller keyboard combos. They seem to be from the 80's. Not sure if they are tube or not. Interested in opening one up one day.
I don't think that's what people mean There's old early amps for other purposes (PA, bass, organ, etc.) that are closely related to the desirable vintage guitar heads and can be changed to guitar specs with just a couple simple mods
That's crazy with all those inputs mounted upwards. I imagine dust would be an issue with that model.
So I learned that there was a 50 watt organ version of the 1987, model number 1989. Apparently there is no organ version of a 1959. The back panel of a 1989 doesn't say Lead, or Bass on it, in fact in that left side area above "Made in England" it says nothing. Blank in that area.
That reminds me. I need to get my hands on some 1/4" yellow dymo label tape and a label maker for it. Because that'll allow me to make correct fuse labels for my back panels I'm making.
There is an older thread where differences between 1986 and 1987 are discussed. https://www.marshallforum.com/threads/difference-jtm-jmp-1987-lead-1986-bass.107840/#post-1836760 As I understand it, the late 1967-1969 1962s are basically organ amps. They are also listed as Lead & Bass (not or) in the Doyle Marshall book p.27. Please correct me if I am wrong. This is what Tanzin wrote then: The circuitry is just like it's supposed to be. Technically it's a model 1962 but for us gear heads the main circuit is a "Bass" (model 1986) with an additional volume pot bypass cap (100pF). BTW, this main circuit setup is identical to the "Organ" amps (model 1989), but normally most of us don't reference this model since they are not to common.
