8+4+4=?

[treelifeUK]

In my quest to be able to hear myself on stage, could I (Mark iv) keep my C90 plugged into the 8 ohm socket and plug a 8 ohm EVM 12L ext speaker into EACH of the two 4 ohm sockets? ie, 8 + 4 + 4. I could then use one of the EV ext cabs as a monitor down at the stage front! Then perhaps, I could hear myself over the piano player, drums and bass! Is this good for the transformers? Probably not. Interested to hear comments?

 

[Russ]

I just read through both the user's manuals for the A and B versions and both say that the use of both 4 ohm jacks present a 2 ohm load to the amp. This is obvious. However, they go on to state that a 2 ohm load will not cause immediate damage but your tube life to be shortened. I would think that if the Mark IV was capable of less than a 2 ohm load then they would mention it in the manual. For this reason, I would suggest not doing it.

You might be able to run your two 8 ohm cabinets as a 16 ohm load if wired properly and use the 8 ohm tap and then use your C90 in one 4 ohm tap. This mismatch 16 into 8 and 8 into 4 has already been told to me by Mesa as being ok.