Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: fossilshark on May 13, 2017, 10:53:18 pm

Title: 50w marshall plexi
Post by: fossilshark on May 13, 2017, 10:53:18 pm
I built a 50w amp thats basically franken-amped out and was thinking about rebuilding it completely (wiring is a mess and there 1000 hack jobs) into a marshall plexi. This looks like the original schematic, but its 100w. If i built it exactly the same except with a 50w poweramp (jcm800 50w poweramp) how would that affect the sound compared to the original 100w version?
Title: Re: 50w marshall plexi
Post by: tubenit on May 14, 2017, 06:13:55 am
I think it would sound very similar if using the same guitar and speaker cabinet.  100w might have more headroom?  However, I think the 50w will be so loud that this wouldn't be an issue in most situations.

Please remember, that Hoffman's Library of Info has a very nice layout and schematic for the 50w Plexi.

http://el34world.com/Hoffman/files/Hoffman_Plexi50.pdf (http://el34world.com/Hoffman/files/Hoffman_Plexi50.pdf)

With respect, Tubenit
Title: Re: 50w marshall plexi
Post by: fossilshark on May 14, 2017, 01:59:34 pm
Thanks, i will check out the Hoffman layout
Title: Re: 50w marshall plexi
Post by: SolidStateCircuitReject on May 17, 2017, 05:00:42 am
I built a 50w amp thats basically franken-amped out and was thinking about rebuilding it completely (wiring is a mess and there 1000 hack jobs) into a marshall plexi. This looks like the original schematic, but its 100w. If i built it exactly the same except with a 50w poweramp (jcm800 50w poweramp) how would that affect the sound compared to the original 100w version?

about the same minus some overhead punchiness - look for schematics for a "1987", which is the 50 watt version of a 1959 - standard super lead. The power sections between 800 and 1959 are identical - the 50 watt versions just have less tubes, less filtering, smaller trannies.