I got a question. I recently purchased a Sunn 1000s amp head, and its output impedance rating is 8 ohms, however, my cab I believe has four 70W green celestions rated at 16 ohms. Is there anything you guys might recommend in regards to the difference in impedance? I just don't want to end up causing any probs with either of the pieces. Lemme know.

Thanks.

You should be able to run it fine a 16 Ohms assuming the amp is solid-state.

If you want to push out more volume, you could probably rewire the cab to operate at 8 Ohms.

is the whole cab rated at 16 ohms, or is each speaker 16 ohms?

gio wrote:is the whole cab rated at 16 ohms, or is each speaker 16 ohms?

this is a good question!

it's a 4x12 cab and each speaker is rated at 16 ohms.

also, for information, it's a tube amp.

polymath wrote:also, for information, it's a tube amp.

Ok, in that case you need to be quite careful. Do not ever run the amp with no speakers connected. Also, you should match the impedance indicated at the socket - in this case 8 ohms.

Does the amp only have an 8 Ohm output?

there's the 8 ohm speaker output, and an additional 4 ohm external speaker output.

can you give me a brief rundown as to why you make thos suggestions for a tube amp, or about what to do concerning the impedance mismatch (what does it mean, exactly)?

Tube amps need to see the correct impedance as they are designed to have a load (speaker) which matches the output impedance of the amp.

When this occurs (impedance matching), we get maximum power transfer. When it doesn't happen, we don't. You risk frying your valves and output transformer if you don't use the correct load.

As a solution, you could rewire your 16-Ohm cab as 4-Ohms by wiring each speaker in parallel.

Otherwise, you could run it into the cab as it is and hope it's ok.


Roddy

you think that blowing the tubes would be something that happened quickly or could just occur over time?