29-07-2022, 02:31 PM
Hi All,
I recently could not resist buying this Marshall amplifier cabinet (Marshall Class 5 - single EL84 with 2 x ECC83's) as a project. It was advertised as a "dummy' cabinet but looked original and I managed to negotiate a price of £60 which I thought was cheap considering it was one with red tolex material being quite rare. The person I bought it from had no idea whether it had a proper chassis or any board etc but I took it as read that it may not have anything inside.
When it arrived, on examining this the chassis is marked as 'dummy" but it is a real model and it does have a circuit board which is the same as the one as the one in my other Class 5 that my late mother bought me on my 50th birthday (near 13 years ago). The challenge I have, hence ask for some advice/thoughts is that the chassis appear to be designed for a later board (which cannot be purchased and are never seen anywhere for sale) where the valve are positioned at the edge of the chassis (see the photo below). The board I have has the valve positioned on the rear of the board and as such have holes drilled in the middle of the chassis to position them. The reason for the change was to do with a major rattling issue with this amp which eventually led to it being sold as a head and cabinet and not a combo, which had the issues.
I don't want to spend masses of time working on this one at the moment so what I have been thinking is:
- can I use the board I have (yes, it looks a wee bit cheap!) and position the valves at the edge of the chassis by adding appropriate leads from where the valve socket mounts in the middle of the board outwards?
- drill holes in the middle of the chassis and mount the bard with no changes as it stands with no modification?
- prepare a handwired board and modify the whole thing albeit my expertise here is very weak indeed (I can't seem to understand still(!!??) how to convert a schematic into a circuit board layout). I've look everywhere and cannot find anyone or anything that explains this in easy terms.
Thanks in advance for any help.
Rob
I recently could not resist buying this Marshall amplifier cabinet (Marshall Class 5 - single EL84 with 2 x ECC83's) as a project. It was advertised as a "dummy' cabinet but looked original and I managed to negotiate a price of £60 which I thought was cheap considering it was one with red tolex material being quite rare. The person I bought it from had no idea whether it had a proper chassis or any board etc but I took it as read that it may not have anything inside.
When it arrived, on examining this the chassis is marked as 'dummy" but it is a real model and it does have a circuit board which is the same as the one as the one in my other Class 5 that my late mother bought me on my 50th birthday (near 13 years ago). The challenge I have, hence ask for some advice/thoughts is that the chassis appear to be designed for a later board (which cannot be purchased and are never seen anywhere for sale) where the valve are positioned at the edge of the chassis (see the photo below). The board I have has the valve positioned on the rear of the board and as such have holes drilled in the middle of the chassis to position them. The reason for the change was to do with a major rattling issue with this amp which eventually led to it being sold as a head and cabinet and not a combo, which had the issues.
I don't want to spend masses of time working on this one at the moment so what I have been thinking is:
- can I use the board I have (yes, it looks a wee bit cheap!) and position the valves at the edge of the chassis by adding appropriate leads from where the valve socket mounts in the middle of the board outwards?
- drill holes in the middle of the chassis and mount the bard with no changes as it stands with no modification?
- prepare a handwired board and modify the whole thing albeit my expertise here is very weak indeed (I can't seem to understand still(!!??) how to convert a schematic into a circuit board layout). I've look everywhere and cannot find anyone or anything that explains this in easy terms.
Thanks in advance for any help.
Rob
if all else fails...read the instructions!