Convert old Carlsberg Sidewinder to JCM800/JTM...
Posted: Fri 06/12/20 3:54 am
I have an old Carlsbro Sidewinder 60 watt EL34 combo. Had it from new. Bought it in preference to a Silver Jubilee JCM 800 - oh why? The ignorance of youth... It was about the same price. It had more knobs.
The preamp sounds dreadful - always did - but I am thinking of converting the amp to a Marshall clone - JCM800 or JTM... Schematic attached. I have also added a document from an engineer who did some work on another one and uploaded his record.
It all works properly and I did replace all the electrolytics a couple of years ago.
It is easy to use the power amp as it is because the power amp and preamp are separated; the power amp on its own chassis and the preamp on a board above it. There is a send/return arrangement. The transformers are good quality and are very heavy (Drakes if I remember properly).
What do you reckon? - Keep the PA without change and build a preamp on turret board, or do you think the PA needs modifying too? I see that the circuit is not that different to a Marshall 50 watt PA.
Any ideas or suggestions are welcome!
The preamp sounds dreadful - always did - but I am thinking of converting the amp to a Marshall clone - JCM800 or JTM... Schematic attached. I have also added a document from an engineer who did some work on another one and uploaded his record.
It all works properly and I did replace all the electrolytics a couple of years ago.
It is easy to use the power amp as it is because the power amp and preamp are separated; the power amp on its own chassis and the preamp on a board above it. There is a send/return arrangement. The transformers are good quality and are very heavy (Drakes if I remember properly).
What do you reckon? - Keep the PA without change and build a preamp on turret board, or do you think the PA needs modifying too? I see that the circuit is not that different to a Marshall 50 watt PA.
Any ideas or suggestions are welcome!