I am wanting to build an amp myself and learn more about amp I would love to do like this 800 reissue 20 where is the best place to get a kit and get it together. Also can anyone help locate a chassis print as I am a sheet metal fabricator. Maybe hook someone up with one for the print.
Jcm 800 reissue 20 watt version
- Thread starter Dave47857
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Chris-in-LA
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Not sure there is a 20 watt reissue kit. Just build the 50 watt version, they sound great at almost any volume. I use Amp Parts Direct for Heyboer transformers and Valvestorm for the boards, wire and electronic parts.
Guitar-Rocker
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It's from ValveStorm
Guitar-Rocker
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If you want to build a lower watt version, determine which power tubes you want to use, source your iron for those, and adapt that to a 2203 style preamp.
Chris-in-LA
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i built a tweed Bassman with a 2204 preamp section. That amp is about 40 watts. I’m sure you could do the same thing with the JTM45 kit. That amp is about 30 watts.
This is the Bassman. It has Marshall knobs on the preamp section
This is the Bassman. It has Marshall knobs on the preamp section
PelliX
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The 2203 and 2204 share the same preamp, it's really just a different output stage (100W vs 50W, 4 valves vs 2).
RCM 800
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Mojotone makes an 18w TMB kit. Guessing Ceriatone probably has some 18 or 20 watt options too but I dont know of any kits that are low watt that use EL34's nor do I know how it would work. Marshall origin 20s use EL34's but I dont know how they did it. A long time ago I built an AX84 high octane. They are single ended and can have an octal option but it only uses one tube for the power amp for about 5watts IIRC.
playloud
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Are you specifically hoping to clone the SC20? I'm not aware of anyone who offers a kit for that. Someone posted a SV20 schematic here recently. I wouldn't be surprised if the SC20 is the "MV version" (i.e. cascaded channel + cold clipper + MV) of that.
The SC20 is unique in that it uses a pair of EL34s with cathode bias. Most 18W/20W kits use EL84s, and are designed around the original Marshall 18W/20W circuits, which are significantly different to a 2203/2204 preamp.
If you're committed to low voltage, I would either build a 2204 kit with 6V6s (as @Dblgun suggests above) or check out these designs from Modulus (still use EL84s but will provide higher gain):
- https://modulusamplification.com/gts-20-plexi-20-watt-valve-amp-kit-3393-p.asp (You could easily cascade this for more gain)
- https://modulusamplification.com/th...-ultimate-hot-rodded-plexi-amp-kit-8724-p.asp
The SC20 is unique in that it uses a pair of EL34s with cathode bias. Most 18W/20W kits use EL84s, and are designed around the original Marshall 18W/20W circuits, which are significantly different to a 2203/2204 preamp.
If you're committed to low voltage, I would either build a 2204 kit with 6V6s (as @Dblgun suggests above) or check out these designs from Modulus (still use EL84s but will provide higher gain):
- https://modulusamplification.com/gts-20-plexi-20-watt-valve-amp-kit-3393-p.asp (You could easily cascade this for more gain)
- https://modulusamplification.com/th...-ultimate-hot-rodded-plexi-amp-kit-8724-p.asp
