Help!! Ampeg B25B with two 1x15 speaker cabs

[banikek]

I need some help from those out there who know something about the Ampeg B25B and speaker wiring.

I have an Ampeg B25B head that I just love. Apparently this amp can run at 8 or 16 ohms only. I trick it into using the 8 ohm tap by using a dummy plug. The tone I get is great either thru a 4x10 or 1x15 cab.

Now, I have two 1x15 cabs. Both are 8 ohm. I like the single 15's because I can take either one or two depending on the size room I am playing. Nice versatility. I would like to retain this versatility AND use the B25B.

Here is what I am thinking. I made a little series/parallel box made up of some switchcraft jacks I had. Now when I plug both 8 ohm cabs into this box, the resulting "speaker out" plug is 16 ohm. I want to now plug this into the B25B (removing the dummy plug) and run a combined 2x15 rig. Have I done something evil? Please let me know if my logic is correct and if there are any risks to this set up.

thanks,
chris

 

[OneWayPunk]

I don't see any reason why that wouldn't work if you wired it correctly.
Your probably safe to also run them normally in parallel at 4 Ohms with the dummy plug in The amp should be able to handle that no prob. Tube amps can handle lower impedance loads much better than solid state amps.

 

[coreyfyfe]

As long as it's wired correctly, you've essentially just made a modular B25 cab. The original cabs were two 8 ohm 15s with a series/parallel switch on the jack plate for 4/16 ohms.

 

[bigdaddyforge]

nope, that's exactly correct. i didn't mind losing the versatility of being able to stack them to 4ohm or single to 8ohm so i wired mine into a 2x15 cabinet @ 16ohm and it's dedicated to the b-25b