Ampeg B25b

[punkrocco]

Hi I just bought a 1970’s Ampeg B25b it runs at 16 ohms and I only have 8ohm speaker boxes,the guy I bought it from says I can use a dummy plug in one of the speaker outlets which should make an 8ohm cab work OK does anyone know if this would work without damaging anything?Thanks in advance Rocco!

 

[leonard]

Yes, there is an 8 ohm tap on the output transformer. I'm sorry but I can't remember if a dummy plug helps. A visit to a competent amp tech is always a good idea.

 

[punkrocco]

Thanks Leonard it’s with a good tech right now cheers and thanks again!

Yes, there is an 8 ohm tap on the output transformer. I'm sorry but I can't remember if a dummy plug helps. A visit to a competent amp tech is always a good idea.

 

[punkrocco]

Thanks Leonard it’s with a good tech right now cheers and thanks again!

 

[coreyfyfe]

On the B25B if you plug a dummy plug into the extension speaker jack it will swap to the 8 ohm tap and allow you to plug the main speaker out into an 8 ohm cab. Use something like a 1/4” headphone adapter as your dummy plug.

You can also have the amp rewired to separate the taps to individual jacks, but the dummy plug works.

 

[punkrocco]

Thanks for your help much appreciated cheers Rocco!