Another dumb OHM question

[doomedfuzz]

I have an Orange Rockerverb 100 head. 2x8ohm outs and one 16ohm out. I usually run a single Orange PPC412 that is 16ohm and have no issues doing so. Now my question: With this amp head, can I run two 8ohm cabs? Reason being, I want to run a full stack and I have an 8ohm Sunn cab and I have the opportunity to pick up another 8ohm cab cheap. Thoughts?

[MEC]

I haven't checked the schematic but if you have two 8ohm speaker outs you should be able to run two 8ohm cabs at the same time.

[the Life Aquatic]

no, u would need to run 2x16 ohm cabs putting both in the 8 ohm jacks. 2x16 ohm cabs will be 8 ohms. also it should tell u in the manual, i have a TT and i remember seeing something in the manual about how to hook up cabs to it

[doomedfuzz]

I didn't get a manual with mine, but I downloaded the PDF and it says NO do not do what I was wanting to. Oh well!!

[MEC]

I just checked the manual out and you guys are correct.

The only way to use two 412 cabs with 8ohm speakers is to rewire them in series making them 32ohms and then daisy chain them for one 16ohm load.

[Toonster]

well he can use can use each 8 ohm cab on an separate output right?

[siamesegun]

well he can use can use each 8 ohm cab on an separate output right?

No, those outputs are wired in a way that the cabs connected to them cannot have a net impedance lower than the rated value. Therefore, two 16 ohm cabs would halve the impedance to 8 ohms which is allowable. Attaching an 8 ohm cab to each output would lower the impedance to 4 ohms, which is lower than the output tranny is designed for and would prove damaging to the head.

Also important to note that a 16 ohm cab and an 8 ohm cab together would combine to an impedance of 5.333 ohms, which is still too low for the head.

Edit:

Check out this site for a bit more explanation and a calculator: http://www.bcae1.com/spkrmlti.htm
Also this: http://www.marktaw.com/recording/Electronics/OhmsAmpsandSpeakers.html