extension cabs with V4B

[jmpiwonka]

i have an ampeg V4B.
i have an ampeg 4x10 cabinet, 8 ohms.
i have another 2X10 that is 4 ohms.

is it safe to run both of those cabs off of the V4B???

 

[drwhiteguy]

Based on my experience with my v4bh, I would say not. The v4b runs in either 4 or 8 ohms, and an 8 ohm cab in series with a 4 ohm cab would give you neither of those ohm ratings.

More expert responses are on the way I'm sure.

 

[jmpiwonka]

Based on my experience with my v4bh, I would say not. The v4b runs in either 4 or 8 ohms, and an 8 ohm cab in series with a 4 ohm cab would give you neither of those ohm ratings.

More expert responses are on the way I'm sure.

yeah that's what i was thinking...6ohms right?
i also thought i read that impedance doesn't matter with tube amps though...heh...who knows?

 

[Willem]

no, that would give you 12 ohms
in parallel however it would give 2.6 ohms

 

[Son of Bovril]

heads usually have their speaker outputs set up in parallel, so if you run cab from an output then you get 2.6 ohms...

thats a no no for the V4B

 

[bbocaner]

v4b has a 2 ohm tap on it's transformer -- 2.6 is probably close enough to 2 so as to not cause problems. I would definately consult an amp tech and make sure it was OK before I tried it though!!

 

[Son of Bovril]

if it has a 2 ohm tap, then it will be fine...

 

[jmpiwonka]

yeah it has 8, 4 and 2 ohm taps...

 

[Son of Bovril]

Then it WILL be fine. I'm not sure whether it would be better to use the 4 or the 2 ohm setting though?

 

[Willem]

I'd say 4, I've read here with tube amps you can go below the impedance while with solid state you can go above the impedance...