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Impendance taps setting on a tube amp

I have decided to try out the Rouge Audio Cronus Magnum integrated amp before I upgrade my speakers. Reading a Cronus review, I understand that the amp comes factory wired to the 8 Ohms taps. To switch to the 4 Ohms setting you actually have to remove the cover and fiddle with the wires a little. The 6-Moons reviewer suggested requesting that the amp be wired to match the owner's speakers' impedance to avoid having to do it yourself.

I currently have the Totem Hawks speakers, which have a nominal impedance of 6 ohms. Here's a quote I got from Totem: "The Hawk exhibits a nominal 6 ohm impedance that is very constant throughout the ban. The minimum is 5.2 ohms."

Given this information, what would be the optimal setting: 4 or 8 Ohms? Should I try both and see what works best? That's pretty much what RA recommended, but I wanted to see what others think or perhaps faced a similar dilemma.

Thank you.
actusreus

Showing 1 response by atmasphere

atmasphere's avatar
atmasphere
12,116 posts
 
The transformer transforms the 4 ohm impedance to the higher impedance that the tubes have to drive. If you load the 4 ohm tap with 6 ohms, the impedance that the tubes see plate to plate will also go up. You will get slightly less power, but the tubes will make less distortion. OTOH, the transformer will not be loaded quite right and so will ring (distort) a bit more. So you get 6 of one/half dozen of the other. It will not hurt the amp.

Bottom line is you just have to try it. I can't think of a good reason to not have the taps available on the outside of the amp. The last thing a manufacturer wants is for the customer to have to open up the unit and mess with it!
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