What to do with extra transformers I have?

[matttornado]

I have an extra 100 watt Power and 100 watt Output transformer for a Marshall Plexi / 800. If I use them for an amp build, does it have to be 100 watts? Can I use 100 watt trannys for a 50 watt or 40 watt build? What are my options? I already have a 100 watt 2203 clone.

Thanks!

 

[glpg80]

You can use the 100W OT for a 50W build but the primary impedances will be off by a factor of two. That means on the secondary your 16 ohm output shifts to the 8 ohm and the 8 ohm shifts to the 4 ohm output. You just won’t have 4 ohm capability.

 

[harddriver]

You can use the 100W OT for a 50W build but the primary impedances will be off by a factor of two. That means on the secondary your 16 ohm output shifts to the 8 ohm and the 8 ohm shifts to the 4 ohm output. You just won’t have 4 ohm capability.

If you built a 50 watter using the 100 Watt Ouput Transformer your 50 watter would hit with the low end and dynamic punch of a 100 watter which would be pretty cool IMHO. When I pull two tubes out of my 100 plexi it still hits harder and punches bigger than my actual 50 watt Marshall so the theory actually works.

Essentially wired as GLPG80 layed out it would be like having a 100 watt amp and pulling two tubes out of it and when you do this you have halve your impedance in the 100 watter, so if driving a 16 ohm load you set the amp to the 8 ohm tap. If driving an 8 ohm load the amp is set tot he 4 ohm tap.

Mojave used to build their Scorpion 50 watt amp with a 100 watt Output transformer for this very reason....so it hit like the 100 watt Peacemaker. You can read about it here:

https://legendarytones.com/mojave-ampworks-scorpion/