Using a Marshall 1960A with my Mark IV

[Herbie the Rad Dorklift]

The Marshall catalogue says the 1960A is 16/4 ohms, does that mean I use my 4ohm output into the Marshall cab?

 

[tony777]

The Marshall catalogue says the 1960A is 16/4 ohms, does that mean I use my 4ohm output into the Marshall cab?

It means exactly that. :lol:

 

[Herbie the Rad Dorklift]

how can it be both? Is there a switch or something? :?

 

[acorkos]

how can it be both? Is there a switch or something? :?

there are 2 jacks and a mono/stereo switch....in mono mode, you plug your speaker cable into your amp's 4 ohm jack and the cab's left jack labeled '4Ohms'.
plugging into the right jack gives you a 16 ohm load....optionally, you can connect your MkIV 8 ohm jack to the 16 ohm cab jack.
Or switch into stereo mode and plug 2 amp heads at 8 ohms into the 2 cab jacks and have at it

 

[Anonymous]

I was running my Mark IV the same way but this only works for one 4x12.
I plugged a 2nd 4x12 set to 4ohm into the 2nd 4ohm jack thinking I would be running each cab properly at 4ohms
but later found by doing this I was actually running at 2ohms which potentially could cause problems.
It did sound good tho - LOL!

I have since changed to a MESA cab because I didn't want to deal with the ohm math headache.
I had issues when we played at ROK back in July, mono 16ohm Krank cabs were provided, I had to run 1 cab to my 8ohm jack.
This mismatch sucked out all my low end - left me with a treble overkill!